E D M U N D J O H N B O W E N

29 A pril 1898 — 19 N ovem ber 1980

Elected F .R .S . 1935

B y R. P. B e l l , F.R .S .

Edmund John Bowen, known to everyone as T ed Bowen, died on 19 N ovem ber 1980 after a short illness. H e was a pioneer in the study of photochem ical reactions and a m ajor contribu tor to our knowledge of the production and quenching of fluorescence, bu t his influence goes far beyond his published scientific work. T here can be few of his pupils, colleagues and other friends who have not benefited repeatedly from his unselfish and enthusiastic help and advice, and his ability to explain abstruse theories in simple term s has helped the understanding of several generations of scientists.

Early life and schooling

T ed Bowen deposited w ith the Royal Society a very full account of his life and work, prefaced by the words— “ H aving struggled w ith the com piling of obituaries on several occasions one is brought to realize the desirability of easing the task of the person chosen to w rite one’s own. H ence these notes.” T h is account has proved invaluable in w riting the present m emoir, particularly this section, and provides yet another example of T e d ’s habitual consideration for others. Passages in double inverted commas are direct quotations from his own account.

T ed Bowen’s paternal great-grandparents were W illiam and M ary Bowen. W illiam, born 1811, was the son of W illiam and Betty Bowen of Hallow, W orcester, and became a gardener at the houses of N athaniel H artland and of Lady Prinn at Charlton K ing’s, Cheltenham . T he eldest of their twelve children, John Bowen (born 1837), was T ed Bowen’s grandfather. He worked as a gardener and a carpenter, and in 1862 he m arried Betty Riley, a farm er’s daughter from Rishworth, Yorkshire. T hey had four children, and their eldest son, Edm und Riley Bowen, born 1866, was T ed Bowen’s father. T he Bowen family thus had firm roots in

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W orcester and the surrounding country, and T ed retained a W or­cestershire accent throughout his life.

“ Edm und Riley Bowen started as a pupil teacher at £60 per annum ; later he was appointed headm aster of the C hurch of England Elem entary School for Boys, St. Jo h n ’s, W orcester. Practically all the parish activities centred round the church, and organisation of them all, including collec­tion of money to build a new school, was his constant care. W hen there were any difficulties people came to him to have them sorted out. T hough his pupils left at the age of 14 m any of them never forgot w hat they owed to his teaching. He built up a m useum in the school, containing a large num ber of minerals, fossils, natural history specim ens from at home and abroad, old guns, pistols and swords. Cannon balls and a sword from the Battle of W orcester were brought in by old boys engaged in excavations in the tow n.” I t is interesting to see here the origins of T ed Bowen’s love of geology, natural history and collecting in general, which persisted throughout the whole of his life.

In 1895 Edm und Riley Bowen m arried Lilias K am ester, daughter of Thom as K am ester of Clewer, W indsor, who was also a carpenter. T hey had two daughters and two sons, of whom T ed Bowen was the eldest. (His brother D r A. R. Bowen became principal of the Technical College, Newark.) T he Bowen family lived in a sem i-detached house near the school, the other half of w hich was occupied by a b ro ther of Edm und Bowen, who had m arried a sister of Lilias Kam ester, and their children. T he com bined gardens of the two houses were large and well stocked with fruit trees, and the Bowen children appear to have led a happy rural existence w ithout too m uch parental discipline. However, T ed Bowen soon came to feel that he and the other Bowen children were isolated from the rest of the com m unity. In his own w ords—

“ T he children from other houses not far away were regarded as belonging to a distinctly lower class. We played with them sometimes in the lane bu t they were not invited into the garden. Social classes were then m uch m ore sharply distinguished and finely divided than now. T here was a fear of picking up bad habits from people of lower standards. Entertainm ents and parties were solely for m em bers of the family—uncles, aunts, nephews and nieces. T here seemed to be no- one in the parish whose social status was not either above or below that of the schoolm aster and the secret am bitions of his wife. W e were definitely over-protected and sheltered.”

T his feeling persisted when T ed Bowen attended his father’s school (1906-10). Both he and his bro ther felt ill-at-ease am ongthe otherpupils, many of whom came from very poor families and were rough and rebellious. T he Bowen boys became self-centred and attentive in class, bu t frightened both of offending the teachers and of the other children:

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w hen school was over they hurried hom e “ w ith feelings of escape” . F rom 1910 to 1915 T ed Bowen attended the Royal G ram m ar School, W or­cester, as a day boy, cycling or walking the two miles from home twice a day. H ere there were presum ably other boys w ith backgrounds similar to his own, bu t he appears still to have led a rather solitary existence. He stubbornly refused to play cricket or football, the alternative being the cadet corps, and he took no part in other activities such as debating or dram atic societies. However, the teaching was good and he was usually top or near the top of the form order. In particular, the sound teaching provided by the chem istry m aster, R. J. Carter, convinced him that he ought to aim at a scientific career.

D uring T ed Bowen’s school days m any other influences contributed to his later scientific developm ent. In addition to the stim ulus provided by his father, he attended lectures at the W orcester M useum on natural history and on general scientific topics, and the Children’s Encyclopaedia provided a welcome source of hom e education. T he Bowen children explored W orcestershire by cycle and became interested in collecting fossils and flint im plem ents, m any of w hich were given to the W orcester M useum .

In D ecem ber 1914 T ed Bowen sat for the O xford scholarship exam inations as a trial run and, apparently to everyone’s surprise, was awarded the Brackenbury science scholarship at Balliol at the age of 16.7. He w ent into residence in O ctober 1915 and, apart from war service, was to spend the rest of his life in Oxford.

U ndergraduate days and war service

T ed Bowen’s first period in Oxford lasted little m ore than a year and was not very profitable. M ost of the college was occupied by officer cadets in training, and the few undergraduates were mainly foreigners or people unfit for service. A lthough lectures and laboratory instruction were available a great deal of time was taken up by the Officers’ T raining Corps. T he Balliol science tu tor, (Sir) H arold H artley, was away on war service, and T ed Bowen was given tutorials by D. H. Nagel of T rin ity College, w hich he described as “ undem anding” . I t is therefore not surprising that towards the end of 1916 he decided to volunteer for training as a gunner officer. T h is training appears to have been very sketchy, being carried out w ithout any actual weapons, and directed mainly towards passing everyone through as rapidly as possible.

In April 1917 T ed Bowen was posted to France as L ieutenant w ith a howitzer unit, and from that date he saw almost continuous war service until the Armistice, taking part in the battle of the Ypres salient, Cam brai and the Somme. T here were heavy casualties in Bowen’s unit, and he was reluctant to talk about his war service, though later he kept in his college room a fascinating collection of shell-cases and the like, and some items

such as G erm an gun-sights eventually turned up as com ponents of his research equipm ent.

T ed Bowen was fortunate in being dem obilized quickly, and was able to return to Oxford for H ilary T erm 1919, which left five term s to go before his final exam inations. (Sir) H arold H artley had now returned to Oxford, and, like m any others, T ed owed m uch to H artley’s tutorials; he also speaks of the influence of W. H. Perkin, N . V. Sidgwick and D. L. Chapm an. One of his m ost distinguished contem poraries at Balliol was C. N. H inshelwood, who also came up in H ilary T erm 1919 after serving as a chem ist in an explosives factory. A lthough only a short tim e was available before finals, H inshelw ood and Bowen were encouraged by H artley to carry out some undergraduate research on the rate of decom position of solids, which form ed the basis for their first published work. In spite of this diversion T ed Bowen was awarded first class honours in 1920. He could not have had m uch tim e during these five term s for non-chem ical activities, and he makes no m ention of any such.

An Oxford career

A fter taking his degree, T ed Bowen’s career followed a very simple course. He was im m ediately appointed a D em onstrator in the Balliol and T rin ity laboratories, which at that tim e looked after m ost of the laboratory work in physical chem istry in the university. T h is was followed in 1921 by a Lectureship at U niversity College, w here he was elected a Fellow and Praelector in Chem istry in 1922, a position w hich he held until his retirem ent in 1965, when he was elected an H onorary Fellow. He was the first Fellow in Chem istry to be elected at U niversity College, and in 1922 the only other scientist was the medical tu tor. D uring his Fellowship tenure he overlapped with eight M asters of the College, a record which very few can equal. He was the only retiring Fellow of the college ever to be made an H onorary (as distinct from Em eritus) Fellow.

T ed Bowen was a loyal m em ber of his college, and his enthusiasm and adaptability m ust have made him a stim ulating tu tor, though possibly sometimes going too fast for his less agile pupils. He served as Junior D ean 1924-35 and as D om estic Bursar 1930-38. He became very interested in the history of the college, and he collected and described in the College Record num erous objects which turned up in the course of repairs and excavations. He also compiled and presented to the College a year-by-year history of the College since 1249, accompanied by photo­graphs of all known prints, drawings and engravings of it.

Bowen was. appointed a U niversity L ecturer and D em onstrator in 1938, initially in the Balliol and T rin ity Laboratories, and then in the U niversity Physical Chem istry Laboratory which replaced them in 1940. In 1952 he acquired the title of A ldrichian Praelector in Chem istry,

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Edmund John Bowen 87

w hich was held by the senior U niversity L ecturer in that subject. As Jun ior P roctor in 1935—36 he served on num erous U niversity com ­m ittees, and he was subsequently an elected m em ber of the G eneral Board of Faculties and a C urator of the U niversity Chest. However, his m ain adm inistrative contributions in the U niversity were related to special interests of his own, and these will be described in the later section on ‘Societies and o ther in terests’. As a com m ittee m em ber he was famed for the speed w ith w hich he could bring m atters to a head and cause decisions to be made, som etim es too quickly for his m ore cautious colleagues.

Early research in photochemistry

A part from the undergraduate work with H inshelw ood on the decom ­position of solids, already m entioned, Bow en’s scientific work was all concerned w ith the interaction of radiation w ith chem ical substances, in particular photochem ical reactions and the production and quenching of fluorescence. U ntil 1940 it was all carried out in the B allio l-T rin ity laboratories, of which he him self has w ritten an excellent history.* S tarting in some cellars in Balliol in 1853, collaboration w ith T rin ity began in 1879, and by the tim e that T ed Bowen started research in 1920 the laboratories had spread into a motley collection of cellars and disused prem ises in both colleges. T he space in w hich he did m ost of his work was partitioned off and fitted w ith crude benches in an old building which had recently been used as bathroom s by T rin ity College. T he original w ater supply was retained, and gas and one power socket (100 volts d.c.) were installed. T h e laboratories had of course no workshop, technician or secretary, and all glass-blowing was done by the research workers themselves. Research funds were meagre, being provided mainly by small grants from the Chemical Society, the Royal Society and Im perial Chem ical Industries; however, this was less im portant than m ight appear, since little of the appropriate equipm ent was available com m er­cially and m ost of the apparatus had to be hom e-m ade.

It is possible tha t the idea of research in photochem istry was first suggested to T ed Bowen by (Sir) H arold Hartley, who kept a small notebook in w hich he wrote down ideas for future research. T hey did in fact collaborate in 1922 in an attem pt to separate the isotopes of chlorine by photochem ical means, a project first suggested by T , R. (S ir Thom as) M erton. At that date isotopes had only recently been discovered, and only very small separations had been effected by diffusion. T he plan was to carry out the hydrogen-chlorine reaction in light which had been filtered through chlorine, consisting m ainly of 35C135C1 and 35C137C1; it was believed that hydrogen would then react preferentially w ith 3 7 Cl3 7 Cl, so that the hydrogen chloride produced would contain chlorine w ith an abnorm ally high atomic weight, which was m easured by the classical * Notes Records R. Soc. Land. 1970, 25, 227.

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m ethods of T*. W. Richards. In Bowen’s own w ords— “ T he apparent a.w. at first appeared to exceed 35.7: when the result neared 37 high hopes were entertained, bu t when it reached 40 it was concluded that som ething had gone w rong!” F u rther exam ination showed that no separation had actually been effected, no doubt owing to the chain character of the reaction, which was not realized at the time. (Owing to disruptions caused by the war Bodenstein’s 1918 papers were not available.)

T he following years saw several m ore significant photochem ical in ­vestigations carried out either by T ed Bowen alone or w ith the unskilled assistance of Oxford undergraduates, who all had to do a year of research in order to obtain an honours degree in chem istry. A lthough the principles underlying photochem ical processes had long been im plicit in the theoretical work of Einstein, little quantitative experim ental in ­form ation was available, and Bowen’s next few papers aimed at filling thisgap.

His equipm ent was extremely prim itive by m odern standards, and was largely hom e-m ade. Initially the light source was a carbon arc street light, obtained from the Oxford city lighting departm ent, though low -pressure m ercury arc lamps became available later. T he reaction vessels were small flat scent bottles, fused on to soda glass tubing. M easurem ents of light intensity were made w ith a hom e-m ade bolom eter, consisting of a single layer of fine copper wire and form ing one arm of a W heatstone bridge. Later a H efner standard amyl acetate lamp was obtained for absolute calibrations of light intensity.

T ed Bowen had always enjoyed making things with his hands, and the necessary ‘do-it-yourself’ activities found him in his element. T h ro u g h ­out his life he accum ulated a large collection of odd com ponents which m ight come in useful some time. One of these was a very large concave m irror, of unknow n origin, which he used to dem onstrate the very high tem peratures which could be produced by focusing the rays of the sun. T his led to the invention by his colleagues of “ Bowen’s Book of 101 Things a Bright Boy can do. Experim ent 1— How to burn a hole in a brick. F irst you find a friendly lighthouse keeper, etc. . . .” A nother example of his adaptability arose at a later date, when the B allio l-T rin ity laboratories were taking over the contents of the private laboratory which the Earl of Berkeley had m aintained at Boars Hill. T h is contained a miscellany of items, including a set of false teeth, of which H artley rem arked— “ Give them to Bowen, he’ll incorporate them in his appara­tus!” In fact they were not wasted, since T ed used them later to dem onstrate that natural teeth fluoresce in ultraviolet light, while a r­tificial ones do not. T he natural teeth were supplied by T ed himself, or by any m em ber of the audience who could be persuaded to subm it: this included on one occasion Lord Nuffield when he was being shown round the new Physical Chem istry Laboratories which he had donated to the University.

Edmund John Bowen 89

T ed Bow en’s hom e-m ade apparatus did not look elegant, appearing to consist largely of tin cans, solder, sealing wax and black paint, bu t it did work. Possibly as a reaction against the m eticulous conductivity m easure­m ents being carried out by H artley, his form er tu to r, T ed was at pains to em phasize to his colleagues that photochem ical research was a very im precise affair, requiring a notched stick rather than a slide-rule or logarithm tables for its in terpretation. T he same attitude was reflected in a verse due to Hinshelwood:

T here was a young fellow nam ed Bowen W ho always em ptied his pipette by blow in’

He said— ‘It doesn’t m atter a bit ‘Because I make up the rest w ith sp it’.’

A t the party given to celebrate T ed Bowen’s election to the Royal Society in 1935 he was presented by his colleagues with a notched stick, in which each division was guaranteed to contain 10 + 2 subdivisions, and also a specially constructed pipette w ith a trum pet-shaped orifice designed to facilitate em ptying by blowing.

In spite of these frivolities, it was clear to everyone in the laboratory that in the years 1923-35 Bowen was producing results of great im ­portance for the developm ent of photochem istry. Q uantum yields of close to unity were found for the decom position of chlorine m onoxide, chlorine dioxide and nitrogen trichloride in carbon tetrachloride solution, while w ith gaseous chlorine m onoxide an efficiency of 2 was found, independent of pressure. T he action of light on gaseous chlorine dioxide gave several cubic centim etres of a dark red liquid, which was tentatively identified as chlorine heptoxide containing dissolved monoxide, though parallel work in Bodenstein’s laboratory showed that it was mainly chlorine hexoxide, and highly explosive. Q uantum efficiencies were also m easured for some photochem ical reactions in organic solids, and the suggestion was made for the first tim e that the prim ary photochemical process m ight be the transfer of an electron w ithin the molecule. A pparent directional effects observed with polarized light were shown to arise only from anisotropic absorbance in the crystal. I t was shown as early as 1926 that the photolysis of aldehydes and ketones had a much lower quantum efficiency in solution than in the gas phase: the explanat­ion given is equivalent to w hat was later term ed the ‘cage effect’, though expressed in different term s.

In 1930 the photochem ical oxidation of acetaldehyde was shown to be a chain reaction, producing peracetic acid and diacetyl peroxide, though a radical mechanism was not identified at that date. In the absence of inhibitors the rate was proportional to the square root of the light intensity, indicating a bim olecular chain-ending process. On the addition of inhibitors the rate became directly proportional to the light intensity, showing that the chain-ending process had changed: this change from

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vocl* to voc I had been predicted theoretically, bu t not previously observed.* A detailed study was also made of the photochem ical oxida­tion of alcohols by dichrom ate solutions, bu t the com plexity of these reactions, which are still im perfectly understood, made it difficult to arrive at any clear-cut conclusions.

As early as 1927 Bowen had investigated luminescence in the oxidation of phosphorus vapour, and had shown that only one quantum of light was em itted during the oxidation of some 2000 P 4 molecules. F rom about 1935 onwards he became increasingly interested in the production and quenching of fluorescence and their relation to photochem ical change. T h is work was in terrupted by the war, bu t received a great stim ulus from the new techniques w hich became available after 1945. These develop­m ents are described in the next section.

W ork on fluorescence; war service, 1939-45

In T ed Bowen’s early work the intensity of fluorescence was m easured either photographically, or w ith alkali-m etal photo-cells, whose ou tpu t was amplified by a single triode or pentode valve. In 1936 he described a ‘quantum counter’, in which light of a wide wavelength range fell upon a fluorescent screen and the intensity of the resulting fluorescence was m easured. T h is device made it possible to measure absolute fluorescence yields, and has been used extensively by other workers, photo-cells being subsequently replaced by the vastly more sensitive photo-m ultipliers.

M ost of the work on fluorescence was carried out w ith polycyclic arom atic hydrocarbons, including anthracene and its derivatives, naphthacene, perylene, coronene and rubrene: m any of these were studied both as solids and in solution, and in a few instances also as vapours. M aterials of high purity were necessary, since even traces of im purities gave rise to spurious effects. In fact, some of the phenom ena observed with m ixtures of hydrocarbons were later to lead to very interesting conclusions about energy transfer. W hen a hydrocarbon is illum inated in the presence of oxygen it may fluoresce or undergo oxidation, and in some instances photo-dim erization also occurs. In addition the fluorescence may be partially quenched either by oxygen or by the solvent, so that in order to obtain a com plete picture m easure­m ents have to be made over wide ranges of hydrocarbon and oxygen concentrations. Seventeen hydrocarbons were studied, and it was found that, in the absence of dim erization, the quantum yields for fluorescence and photo-oxidation always added up to approxim ately unity, showing that no chain processes were set up.

W ork along these lines continued up to 1939, and to some extent during the war period, though there were m any interruptions. A lthough

•T h is paper (£ . J. Bowen & E. L, Tietz, J . Chem.S&c. 1930, 234) contains a confusing misprint in table VII, in which y jP should read y jl .

Edmund John Bowen 91

T ed Bowen rem ained in O xford during the war, there were m any calls on his tim e and energy. Several of his colleagues were away, so that the teaching load was increased, and m atters were com plicated by the transfer in 1940 of laboratory teaching in physical chem istry from the B allio l-T rin ity laboratories to the new U niversity Physical C hem istry Laboratory, in w hich Bowen took an active part. One of his m ost valuable functions during th is period was to act as a channel of com m unication betw een his colleagues and H inshelw ood, who was head of the labora­tory. H inshelw ood was rarely inclined to discuss problem s w ith other people, bu t he always seemed willing to listen to T ed Bowen. He was a m em ber of the O xford research team w orking on respirator problem s for the M inistry of Supply, and he acted as an A ir Raid W arden throughout the war, though O xford was never bom bed.

T h e end of the war brought particular benefits to T ed Bowen’s research, in that various electronic and optical devices w hich had been developed for m ilitary purposes gradually became available for general use. T he m ost im portant of these was the photo-m ultip lier, w hich made it possible to m easure low light intensities w ith a vastly greater sensitivity and accuracy than h itherto , especially when used in conjunction w ith a fluorescent screen as in Bowen’s “ quantum counter” . Some of this equipm ent was initially available as war surplus at an airfield near Oxford, w here it was sold by the hundredw eight. T h e sum to be paid was determ ined by weighing the custom er’s car on entering and leaving the establishm ent, and it was always believed by T e d ’s colleagues that his car w ent in loaded w ith scrap iron, which was unloaded on the site; occasionally the estim ated am ount of equipm ent purchased came danger­ously close to being negative!

T hese increased technical facilities led to m any im portant investiga­tions of the relations between fluorescence, quenching of fluorescence and various photochem ical reactions, only some of which can be referred to here. In the case of anthracene and its derivatives a study of the dependence of the fluorescence intensity and the rates of photo-oxidation and photo-dim erization on the concentrations of oxygen and hydrocar­bon led to the conclusion that oxygen could deactivate the excited singlet state of the anthracene molecule, bu t could react only with the trip let state: on the other hand, dim erization was held to involve reaction of a singlet excited molecule w ith one in the ground state. T h is was one of the earliest dem onstrations of different chemical reactivities exhibited by different electronically excited states. A long series of papers in the years 1947-59 examined the effect on fluorescence quenching of various factors, particularly tem perature. T his last effect is a small one and is difficult to unravel, since a change of tem perature may affect (a) the fraction of the incident light absorbed, (b) the volume of the solution and hence its concentration, (c) the frequency distribution and distribution in space of the em itted fluorescence, (d) the collectable fraction of the

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fluorescence (because of changes in refractive index) and (e) effects due to dissolved oxygen or self-quenching. It was finally concluded that quenching could occur in two ways, a tem perature-dependent process in w hich the singlet excited state is converted into the trip let by therm al activation, and a tem perature-independent process in w hich the singlet—trip let selection rules are broken down by interaction w ith the quencher, in particular a solvent molecule. However, all the tem perature effects are rather small, and this line of investigation ultim ately proved rather unprofitable.

M uch m ore interesting conclusions followed from the study of the quenching of fluorescence from hydrocarbons by strong quenchers such as 0 2 and S 0 2 in the gas phase and in solvents of varying viscosity. In the vapour such quenching occurs at almost every collision. In solution the quenching efficiency for a given hydrocarbon-quencher system varies closely w ith the viscosity of the solvent, w hich governs the diffusion coefficients: in addition there is a small am ount of ‘static’ quenching, arising from hydrocarbon-quencher pairs w hich are initially in contact, and therefore do not need to diffuse together. For a given solvent the apparent quenching constants vary widely w ith the nature of the hydrocarbon. However, if these apparent constants are converted to absolute rates by allowing for the different fluorescent yields and mean lives of the excited state (calculated from the areas of the absorption bands), then the absolute quenching rates become almost identical for different hydrocarbons, and have values very close to those calculated from simple diffusion theory by assum ing that quenching takes place on every encounter and assigning reasonable values to the molecular dia­meters. T h is simple conclusion, w hich applies both to quenching by oxygen and to ‘concentration’ quenching by the hydrocarbon itself, represented a m ajor contribution to the subject.

A nother kind of effect of added substances was observed in the fluorescence of perylene vapour. In the absence of added gases the fluorescent yield depends on the wavelength of the exciting light and on the tem perature. T h is is because the probability for the excited species to pass over into the non-radiating trip let state is higher the higher the vibrational level. A ddition of non-quenching foreign gases causes the rapid vibrational deactivation of the excited molecules and thus enhances the fluorescent yield. T he results were used to com pare the efficiencies of several additives in rem oving vibrational energy.

Studies of m ixtures of two fluorescent substances gave inform ation about the transfer of electronic excitation energy between molecules which has far-reaching consequences in a num ber of fields. T he first observations (1943) related to anthracene crystals containing traces of naphthacene, which show green fluorescence due to emission by naphthacene, rather than the blue fluorescence characteristic of highly pure anthracene. One part in 105 of naphthacene in solid anthracene is

Edmund John Bowen 93

sufficient to produce a detectable change in fluorescence. Q uantitative studies showed that the results could not be explained by prim ary light absorption by naphthacene, nor by secondary fluorescence caused by the re-absorption by naphthacene of prim ary anthracene fluorescence, bu t m ust arise from the m igration of energy through the crystal from excited anthracene to naphthacene.

Sim ilar behaviour was observed for o ther solid solutions, bu t none of these com pounds was very soluble in liquid solvents, and no energy transfer could at first be detected in liquid solutions. However, following the work of Forster on dyes in alcoholic solution it was found that the same effects occurred in pairs of arom atic substances having higher solubilities in non-polar solvents. T h e m ost unam biguous dem onstration was given for benzene and chloroform solutions containing 1-chloroan- thracene (the light absorber and energy donor) and perylene (the energy acceptor and fluorescence em itter). In the words of R obert Livingston, who collaborated in some of this work:

‘If anyone deserves credit for our experim ental proof of the occurrence of energy transfer by inductive resonance it is E. J. Bowen. He picked out a pair of com pounds which made the proof possible. T h e fluorescence efficiency of the donor com pound, while appreciable, was m uch less than that of the acceptor. U sing an equim olar m ixture of the two substances, the total fluorescence emission of the solution increased as the total concentration was increased. T h is elim inates the “ triv ial” mechanism. T he inde­pendence of the efficiency of energy transfer from the viscosity of the solvent eliminates any diffusion-controlled m echanism. W e also showed [by absorption spectrom etry] that mixed dim ers did not form to any appreciable ex ten t.’#

T h e above results indicated that energy transfer could take place over distances considerably greater than a molecular diam eter. T he final proof of this came in 1954 from a study of the same system in a rigid glass at low tem peratures, from w hich it was clear that the effect could not depend on any collisional m echanism , bu t m ust involve energy transfer over a distance of about 3 nm.

D uring the ten years or so preceding his retirem ent in 1965 T ed Bowen’s research work continued unabated. He did not break m uch new ground, bu t im proved facilities and collaboration with some senior co­workers enabled him to extend and refine many of his earlier in ­vestigations. Topics investigated during this period include the fluor­escence of acridine, acridone and naphthylam ine, the photochem istry of diphenylam ine, and the effect of tem perature and viscosity on the quenching of fluorescence. He had been fascinated by chem ilum ines­cence ever since his study in 1927 of the glow accompanying the oxidation*R. Livingston 1960 in Comparative effects of radiation, p. 326. New York: Wiley.

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of phosphorus vapour, and the availability of detecting systems which would respond to a few photons per second in the visible region made it possible in 1963 to make a quantitative study of the weak light em ission during the decom position of organic peroxides in solution. T h is work, in w hich he was ably assisted by D r R. A. Lloyd, dem anded extrem e refinements of purity and technique to achieve reliable results. I t was shown that the phenom enon is extrem ely sensitive to the presence of dissolved oxygen, and that part of the lum inescence is due to em ission from excited oxygen molecules.

T heoretical chemistry and photobiology

T he period of T ed Bowen’s scientific activity coincided w ith the grow th of the quantum theory, and this was of course fundam ental to the understanding of the interaction between radiation and m atter. A lthough Bowen was prim arily an experim ental chem ist he fully realized the im portance of these theoretical developm ents, and he contribu ted a great deal towards their understanding by chem ists. He was certainly no m athem atician, and may well have sym pathized w ith his pupil (probably mythical) who on seeing a differential sign would tu rn the page over quickly: if he then saw an integral sign he w ould close the book and go out to coffee. N evertheless, T ed Bowen had a rem arkable gift for grasping the essence of quantum -m echanical argum ents and for explaining them to other people by means of simple diagrams and models. In this connection he was fond of quoting R. W. W ood’s saying— ‘A half-tru th is sometimes better than a whole tru th : like a half-brick it carries fu rth er’.

H is enthusiasm for com m unicating inform ation to others found ex­pression in his book Chemical aspects of light (1941, 2nd ed, 1946) and in som ething like 30 lectures and review articles, listed in the Bibliography. M any of these are simple expositions of various aspects of quantum theory, while others sum m arize general fields of photochem istry, fluor­escence and luminescence, including their practical applications and instrum entation. T hese articles include several for the School Science Review, and his Christm as lectures for children in Oxford were colourful both in their delivery and their practical dem onstrations.

Tow ards the end of his life T ed Bowen became increasingly interested in photosynthesis and other aspects of photobiology. A lthough he did not him self carry out experim ental work in this field, he had a sound background knowledge of many branches of biology and was able to make many valuable (and often anonym ous) contributions to the in terpretation of other people’s work. These contributions were widely appreciated, and when the Fourth International Photobiology Congress was held in Oxford in 1964 he was chosen as President, and he also edited the resulting publication, Recent progress in photobiology. He also took part in the F ifth Congress in 1968 at D artm outh , N .H ., U .S .A ., and the Sixth in

Edmund John Bowen 95

1972 at Bochum , G erm any. A t the F ifth Congress he was presented w ith the Niels F insen G old M edal, aw arded under the auspices of the Comite In ternational de la Lum iere.

Societies and other interests

T ed Bowen was elected a Fellow of the Royal Society in 1935, served on Council 1943-45 and was aw arded the Davy M edal in 1963. He served as a Council M em ber and V ice-President of both the Chem ical Society and the Faraday Society, and was Liversidge L ecturer of the Chemical Society in 1966. H e was active in several im portan t early D iscussions of the Faraday Society, notably on Photochem ical reactions in liquids and gases (Oxford, 1925), Photochem ical processes (Liverpool, 1931) and Lum inescence (Oxford, 1938). T h e present w riter was an undergraduate w hen the first of these m eetings took place, and the vivid im pression still rem ains of a young and enthusiastic T ed Bowen arguing volubly w ith various English and foreign greybeards: unfortunately his delivery was rather too rapid for the linguistic abilities of some of the latter.

A lthough he had little enthusiasm for such activities, Bowen was naturally draw n into a num ber of national com m ittees, including the Chem ical Defence Com m ittee of the W ar D epartm ent, the Physical and Inorganic Chem istry Com m ittee of the M inistry of Supply, the L iquid Fuels Com m ittee of the M unitions chem istry Advisory Board, and the Propellants and Internal Ballistics Com m ittee. M uch m ore to his taste was his service on various scientific (but non-chem ical) bodies w ithin the U niversity. He had a rem arkable depth of knowledge in m any branches of science outside his own, and his practical interest is shown by the fact that he became a m em ber, and subsequently Chairm an, of the Delegates of the U niversity M useum , the Com m ittee for Scientific Collections, the Com m ittee of the M useum of the H istory of Science and the Visitors of the U niversity Observatory.

These interests stem m ed in particular from his life-long hobby of collecting fossils and objects of antiquarian interest, which he gave away freely to experts and m useum s. As a schoolboy he collected and gave to the W orcester M useum Palaeolithic and N eolithic flints from the neigh­bourhood. He presented m any am m onites from the local K im m eridge clay, and fossil lobsters from D orset, to the Geology D epartm ent of O xford U niversity, and num erous Perisphinctes from Ringsted Bay to D r W. J. Arkell, F .R .S . These included hitherto unrecognized species, one of which was nam ed Perisphinctes boweni after him. In 1965 he presented a large collection of fossils to the newly extended Geology D epartm ent of the U niversity of Leicester. T o the Ashmolean M useum , Oxford, he gave an uncom m on type of m esolithic axe, coins, and a small iron quarrel or mediaeval cross-bow bolt head, found on his w ar-tim e allotm ent in the U niversity Parks, and other local objects were given to the Oxford City M useum and the Oxfordshire C ounty M useum at W oodstock. He also

96 Biographical Memoirs

presented books, pictures and other objects to the M useum of the H istory of Science, Oxford, including the 1st edition of The natural history of Oxfordshire by Robert Plot, and The spring of the air by R obert Boyle.

In spite of his interest and expertise in geology, T ed Bowen does not appear to have published anything in this field. He did, however, make several contributipns to the history of science, notably a pam phlet (with M. Purver) on the origins of the Royal Society, and articles on the developm ent of chem istry in Oxford. H is interest in the lives of scientists is also shown by the fact that he was the author of three Royal Society biographical memoirs (of D. L. Chapm an, D. LI. H am m ick and C. A. Coulson). He frequently gave unexpected glimpses of other facets of historical knowledge: for example, at the m om ent when the election of Pope John X X III was announced, he surprised the Senior Com m on Room by quoting accurately from m em ory G ibbon’s account of the election of the A nti-Pope. On the other hand, he showed little or no interest in religion, art, music, politics, sport, foreign languages or Small­talk (except for jokes, in which he took a boyish delight).

In the period 1920—26 T ed Bowen went on several walking and clim bing holidays in Britain and abroad, including the first postw ar meet of the Oxford U niversity M ountaineering Club in the French and Italian Alps. Such strenuous trips did not continue for long after his marriage, bu t he retained an interest in such activities by becom ing secretary of the A. C. Irvine Travel Fund, which makes grants to Oxford undergraduates for holidays in m ountainous regions. H is next trip abroad appears to have been with the Faraday Society to Canada in 1952. He was a m ost stim ulating m em ber of the party, and on the voyage out was tireless in using his hom e-m ade telescope and his apparently inexhaustible know ­ledge to identify birds, dolphins, icebergs, celestial objects, etc. and to explain them to his fellow-travellers. In 1959 he visited some 20 universities in India and Pakistan at the request of the Com m onwealth Relations Office to investigate the need for scientific staff on tem porary transfer from British universities. He was cordially received and m ade valuable personal contacts, though he was saddened by the difficult conditions under w hich many of the science departm ents had to operate. T he meetings of the International Photobiology Congress in the U .S.A . (1968) and in G erm any (1972), already m entioned, gave him the oppor­tunity to visit several universities in these countries. In the early part of his career T ed Bowen had little opportunity to visit scientists in other countries, partly owing to the war and partly owing to his reluctance to put him self forward: during his 45 years as a college and university teacher he appears never to have sought the sabbatical leave which many of his colleagues frequently enjoyed. He therefore valued all the m ore the opportunities for travel which arose during his last 20 years, when he had valuable contacts w ith em inent photochem ists such as T erenin of the U .S .S .R . and Jablonski of Poland.

Edmund John Bowen 97

Family life and personal characteristics

In 1924 T ed Bowen m arried E dith M oule, eldest daughter of Joseph and M argaret M oule of H artlebury, W orcestershire. M em bers of the M oule family had been yeom an farm ers in the H artlebury district for at least 350 years, and T ed was able to add general farm work and rough shooting to the other outdoor activities w hich he loved. T h e ir m arriage was a very happy one, and their golden w edding in 1974 was celebrated by a large family gathering in U niversity College. T hey had two children, M argaret Lilias, born in 1927, and H um phry John M oule, born in 1929. Both children had distinguished university careers, though only H um phry inherited his father’s scientific leanings; he became a Senior Scientific Officer at A .E .R .E ., H arwell, and then a L ecturer in C hem istry at Reading U niversity. Both H um phry and M argaret had three children, and T ed had the satisfaction as a grandfather of seeing the name Bowen appear once m ore on the rolls of both Balliol and U niversity Colleges.

T he Bowens started their m arried life at 15 Banbury Road, bu t in 1934 bought a large house at 10 Park Tow n, w hich gave T ed m ore scope for his energy and ingenuity in doing odd jobs in the house and the garden and provided m ore space for the rapidly growing collection of am monites: this rem ained their home up to the present day. T he present w riter returned to Oxford in 1932 as a newly m arried and very jun io r don, and he and his wife still have warm recollections of the hospitality shown by T ed and E dith Bowen and the m any ways in w hich they helped them to fit into a new environm ent. M any others m ust owe similar debts of gratitude. In 1937 T ed Bowen built a holiday house, designed by himself, in Ringstead Bay in D orset. T h is area was ideal for pursuing his geological interests, and the house provided yet another place for entertaining his friends. I t was requisitioned during the war, bu t was returned in 1947 and used several times a year thereafter during vacations. It was a m ost valued possession, and may have helped to m aintain his excellent health, which he enjoyed almost to the end.

T he many personal tribu tes to T ed Bowen from his friends and colleagues refer repeatedly to his enthusiasm , his energy and his kindness to others. He seemed to retain all his life the innocence of a naturally good child, untem pered by self-interest or desire for recognition. One of his form er colleagues described his life as one of the strongest argum ents against the doctrine of original sin. T ed loved giving things to people and doing things for them . Some of his gifts to m useum s and other institutions are m entioned in the preceding section, bu t there were also many individual acts of kindness, as the w riter can illustrate from his own experience. W hen I returned to O xford in 1932 T ed im mediately presented me with an old engraving of Balliol College and a Balliol coin. Some years later, when we had moved into a new house, I casually rem arked to T ed that it would be nice to be rid of an old quince tree in the

98 Biographical Memoirs

garden. He arrived the next m orning w ith the appropriate tools, rem oved the tree, and, typically enough, unearthed a 17th century metal token and the vertebra of a prehistoric animal in the process. Similarly, in the laboratory I was once careless enough to reveal that a com ponent of T e d ’s apparatus was ju st w hat I needed for one of my own experim ents. It was im m ediately removed and handed over, w ith the com m ent ‘I expect I can find som ething else which will do ju st as w ell’. O n another occasion he presented me with a copy of D irac’s book on quantum theory, saying ‘I don ’t understand a word of this, bu t perhaps you can tell me if there is anything in it’.

T ed Bowen changed rem arkably little in youthful appearance over fifty years or so, and even less in boyish character. One of his colleagues who had a long talk w ith him a few days before his death reports that he still seemed to have the verve, enthusiasm and freshness of a m an in his twenties. It is indeed fortunate that he did not suffer any long or painful illness, but died shortly after a heart attack on 19 N ovem ber 1980.

Thanks are due to m any people for their assistance in w riting this memoir, and I would like to m ention particularly M rs Edith Bowen, D r H. J. M. Bowen, Professor W. J. A lbery, Professor J. N . P itts, Lord Redcliffe-M aud, Sir Rex Richards, Professor Brian Stevens, the Very Reverend J. H. S. W ild and Professor J. H. W olfenden.

T he photograph reproduced was kindly provided by D r H. J. M. Bowen.

B ibliography

Original papers on photochemistry, fluorescence and related subjects1922 (With H. B. H artley, A. O. Ponder & T. R. M erton) An attempt to separate the isotopes of

chlorine. Phil. Mag. 43, 430.1923 The photochemistry of unstable substances. chem. 1199.

The photochemical decomposition of chlorine monoxide. chem. Soc. 2328.1924 (With H. B. H artley, W. D. Scott & H. G. W atts) The rate of photochemical change in

solids. J.chem. Soc. 1218.The photochemistry of the halogen hydrides. J. chem. Soc. 1233.

1925 (With H. Booth) The action of light on chlorine dioxide. J. chem. Soc. 510.(With J. F. Sharp) The photochemical decomposition of nitrosyl c h lo r id e .chem. Soc. 1026. A note on the photoactivation of chlorine. Phil. Mag. 50, 879.

1926 The dissociation theory and photochemical thresholds. Trans. Faraday Soc. 21, 543.(With H. G. Watts) The photolysis of acetaldehyde and of acetone. chem. Soc. 1607.

1927 (With E. G. Pells) A study of the chemiluminescence of phosphorus vapour. J. chem. Soc.1096.

(With C. W. Bu n n ) The photochemical oxidation of alcohols by the dichromate ion. I. 7. chem. Soc. 2353.

1929 (With E. T . Yarnold) Photochemical oxidation of ethyl alcohol by potassium dichromate IIJ. chem. Soc. 1648.

1930 (With E. L. T ietz) Photochemical interaction of acetaldehyde and oxygen. chem. Soc. 234.1931 (With T. A. Peacocke & E. R. W ellburn) Photochemical oxidation of alcohols by potassium

dichromate. III. chem. Soc. 1866.

Edmund John Bowen 99

1932 (With W. M. Cheung) Photodecomposition of chlorine dioxide solutions.^. chem. Soc. 1200. (With J. Chatwin) Photochemical oxidation of alcohols by potassium dichromate. IV. J.

chem. Soc. 2081.Light filters for the mercury lamp. J. chem. Soc. 2236.

1934 (With F. Steadman) Photo-oxidation of rubrene. J. chem. Soc. 1098.(With E. L. A. E. de la Praudiere) Photoreactions of liquid and dissolved ketones. I. J. chem.

Soc. 1503.(With A. T. H orton) Photoreactions of liquid and dissolved ketones. II. J. chem. Soc. 1505. (With H. W. T hompson) Photochemistry and absorption spectrum of acetone. Nature, Lond.

133, 571.1935 Light filters for the mercury lamp. J. chem. Soc. 76.1936 (With A. T. H orton) Photoreactions of liquid and dissolved ketones. III. J'. chem. Soc. 1685.

Heterochromatic photometry of the ultraviolet region. Proc. R. Soc. Lond. A 148, 349.1937 (With J. W. Sawtell) The fluorescence efficiencies of solutions of hydrocarbons. Trans.

Faraday Soc. 33, 1425.1938 Fluorescence of solids. Nature, Lond. 142, 1081.1939 Fluorescence in solution. Trans. Faraday Soc. 35, 15.

(With A. N orton) Quenching of fluorescence in solution. Trans. Faraday Soc. 35, 44. (With A. H. W illiams) Photo-oxidation of hydrocarbon solutions. Trans. Faraday Soc. 35,

765.1942 The reversible quenching by oxygen of the fluorescence of polycyclic hydrocarbons. Nature,

Lond. 149, 528.1943 Fluorescence spectra of naphthacene molecules in solid solution in anthracene with variation

in wavelength. Nature, Lond. 153, 653.1945 The fluorescence of naphthacene in anthracene. J. chem. Phys. 13, 306.1946 (With E. Coates) Quenching of fluorescence by van der Waals forces. Nature, Lond. 157, 548.1947 (With A. W. Barnes & P. H olliday) Bimolecular quenching processes in solution. Trans.

Faraday Soc. 43, 27.(With E. Coates) Solvent quenching of fluorescence. J. chem. Soc. 105.(With J. D. F. M arsh) The photochemical dimerisation of acenaphthylene.^, chem. Soc. 109. (With E. Coates) Stereo-effects and van der Waals complexes. J. chem. Soc. 130.(With E. M ikiewicz) The fluorescence of solid anthracene. Nature, Lond. 159, 706. Fluorimeter design. Analyst, Lond. 72, 377.

1949 (With E. M ikiewicz & F. W. S mith) Resonance transfer of electronic energy in organic crystals. Proc. phys. Soc. A 62, 26.

(With P. D. L awley) Crystal size and fluorescence intensity. Nature, Lond. 164, 572. Chemistry and weak light effects. Br. Sci. News 3, 38.The action of light on dyes. J. Soc. Dyers Colour. 65, 613.

1951 (With W. S. M etcalf) The quenching of anthracene fluorescence. Proc. R. Soc. Lond. A 206, 437.

Resonance transfer of energy between molecules. Symp. Soc. exp. Biol. 5, 152.1953 The photochemistry of anthracene. I. The photo-oxidation of anthracenes in solution.

Discuss. Faraday Soc. 14, 143.(With K. K. Rohatgi) The photochemistry of anthracene. II. The photochemical reaction of

anthracene with carbon tetrachloride. Discuss. Faraday Soc. 14, 146.(With R. J. Cook) Temperature coefficients of fluorescence. J. chem. Soc. 3059.(With B. Brocklehurst) The fluorescence spectrum of coronene. J. chem. Soc. 3318.(With B. Brocklehurst) Energy transfer in hydrocarbon solutions. Trans. Faraday Soc. 49,

1131.The spectrophotometry of fluorescence and phosphorescence. Photoelect. Spectrum. Grp Bull.

6, 124.1954 Fluorescence quenching in solution and in the vapour state. Trans. Faraday Soc. 50, 97.

(With B. B rocklehurst) The fluorescence spectra of coronene and 1,12-benzoperylene at lowtemperatures. J. chem. Soc. 3875.

(With R. L ivingston) An experimental study of the transfer of energy of excitation between unlike molecules in liquid solutions. J. Am. chem. Soc. 76, 3600.

1955 (With B. Brocklehurst) Energy transfer in rigid solvents. Trans. Faraday Soc. 51, 774. (With B. Brocklehurst) The emission spectra of aromatic hydrocarbons in crystalline

paraffins at — 180°C. J. chem. Soc. 4320.(With K. W est) Solvent quenching of the fluorescence of anthracene. J. chem. Soc. 4394.

100 Biographical Memoirs

1955 (With D. W. T anner) Photochemistry of anthracenes. III. Inter-relations between fluor­escence quenching, dimerisation and photo-oxidation. Trans. Faraday Soc. 51, 475.

1956 The photochemical oxidations of alcohols by dichromate. Nature, Land. 177, 889.(With S. Veljkovic) The enhancement of the fluorescence of vapours. Proc. R. Soc. Lond.

A 236, 1.1957 (With D. M. Stebbens) Solvent quenching of fluorescence. J. chem. Soc. 360.1958 (With J. Sahn) The fluorescence of acridine and acridone solutions. J. chem. Soc. 3716.1959 (With J. Sahn) the effect of temperature on fluorescence of solutions. J. phys. Chem. 63, 4.

(With S. F. A. M iskin) The effect of viscosity on the fluorescence yield of solutions. J. chem.Soc. 3172.

Viscosity and temperature effects in fluorescence. Discuss. Faraday Soc. 27, 40.1961 Fluorescence measurement. Photoelect. Spectrom. Grp Bull. 13, 331.1962 (With N. J. H older & G. W. W oodger) Hydrogen bonding of excited states. J. phys. Chem.

66, 2491.(With D. Seaman) The efficiency of solution fluorescence. Luminescence Org. Inorg. Mater.

Int. Conf., New York, p. 153.1963 (With J. H. D. Eland) Photochemistry of diphenylamine solutions. Proc. chem. Soc. 202.

(With R. A. L loyd) Chemiluminescence of organic peroxide decomposition. Proc. R. Soc.Lond. A 275, 465.

(With R. A. L loyd) Chemiluminescence from dissolved oxygen. Proc. chem. Soc. 305.1964 Chemiluminescence in solution. Pure appl. Chem. 9, 473.

Chemiluminescence of dissolved oxygen. Nature, Lond. 201, 180.

Books, review articles and lectures1931 (With N. V. S idgwick) The structure of simple molecules. Rep. Prog. Chem. 28, 365.1932 Photochemistry. Rep. Prog. Chem. 29, 46.

The structure of simple molecules. Rep. Prog. Chem. 29, 59.1933 Chemical kinetics. Rep. Prog. Chem. 30, 46.

Molecular structure. Rep. Prog. Chem. 30, 79.The rusting of iron. Sch. Sci. Rev. 14, 139.

1934 Chemical kinetics. Rep. Prog. Chem. 31, 46.1935 The state of carbon dioxide in aqueous solution. Sch. Sci. Rev. 16, 560.1941 The chemical aspects of light. Oxford University Press. (2nd edn, 1946).1943 The absorption spectra of organic substances and wave mechanics. Rep. Prog. Chem. 40, 12.1944 Developments of valency theory. Cherny Ind. 338, 491.

Wave mechanics. Fluorescence and phosphorescence. Reaction velocity theory. Postgraduate lectures in physical chemistry. London: Oil and Colour Chemists Association. 32 pages.

1945 Valency links. Mon. Sci. News No. 3.Particles, waves and chemical formulae. Endeavour 4, 75.

1946 Luminescence (solids, liquids and gases). Thorpe's dictionary of applied chemistry (4th ed.) 7,405. London: Longmans.

Physical states of aggregation. Sci. Prog., Oxf. 34, 477.1947 Fluorescence and fluorescence quenching. Q. Rev. chem. Soc. 1, 1.

Wave mechanics and electron patterns. Sch. Sci. Rev. 28, 164.The absorption of light by chemical compounds. (4th John Mercer Lecture.) J. Soc. Dyers

Colour. 63, 281.Fluorescence quenching in solution. Analyst, Lond. 72, 379.

1949 Photochemistry. Thorpe's dictionary of applied chemistry (4th ed.) 9, 526. London: Longmans. Photosynthesis in plants. Thorpe's dictionary of applied chemistry (4th ed.) 9, 592. London:

Longmans.1950 Light absorption and photochemistry. Q. Rev. chem. Soc. 4, 236.1952 The luminescence of organic substances. Nucleonics 10, no. 7, 14.1953 (With F. W okes) The fluorescence of solutions. London: Longmans.

Photochemistry. Encyclopaedia of Chemical Technology 10, 510. New York: Interscience.1954 Fluorescence. J. Oil Colour Chem. Ass. 37, 264.1955 The use of fluorescence for industrial analysis and examination. Mol. Spectrosc. 1. London:

Institute of Petroleum.1960 Fluorescence. Ciba Rev. 12, 2.

(With M. Purver) The beginnings of the Royal Society. Oxford University Press.

1963 The photochemistry of aromatic hydrocarbon solutions. Adv. Photochem. 1 , 23.1965 (Editor) Recent progress in photobiology. Oxford: Blackwell.1966 Light emission from organic molecules. Chem. Br. 2, 249.

(With G. F. J. G arlick) Luminescence. Int. Sci. Technol. No. 56, 18; 78.1968 Fluorescence and luminescence in biology. In: Energetics and mechanisms in radiation biology

(ed. G. O. Phillips). London: Academic Press.(Editor) Luminescence in chemistry. London: Van Nostrand.

1972 Chemi- and bio-luminescence. Res. Prog. Org. Biol. Med. Chem. 3, 100.1974 The development of chemical ideas of light. In: Progress in photobiology (ed. G. O. Schenk).

Frankfurt: Deutsche Gesellschaft f. Lichtforschung.1975 Wave mechanics and organic photochemistry. Photochem. Photobiol. 21. (Guest editorial.)

Edmund John Bowen 101

Miscellaneous publications1920 (With C. N. H inshelwood) The rate of chemical action in the crystalline state. Phil. Mag. 40,

569.1921 (With C. N. H inshelwood) The influence of physical conditions on the velocity of

decomposition of certain crystalline solids. Proc. R. Soc. Lond. A 99, 203.1922 (With C. N. H inshelwood) Uber die Geschwindigkeit chemischer Umwandlung fester

Stoffe. Z. phys. Chem. 101, 541.1925 (With H. Booth) The heats of solution and of decomposition of chlorine dioxide. J. chem.

Soc. 342.1929 (With A. C. Cavell) The oxidation of phosphorus vapour. J. chem. Soc. 1920.

(With E. L. T ietz) The oxidation of acetaldehyde by oxygen. Nature, Lond. 124, 914.1930 The history of science at University College, Oxford. College Record p.49.1931 (With E. A. M oelwyn-H ughes & C. N. H inshelwood) Kinetics of the decomposition of

carbon tetrachloride,solutions of ozone and of ozone-chlorine mixtures. Proc. R. Soc. Lond. A 134, 211.

1932 Scientific museums and laboratories. In: Handbook to the University of Oxford. OxfordUniversity Press. (Also later revisions.)

1934 Contribution to a discussion on energy distribution in molecules. Proc. R. Soc. Lond. A 146, 254.

1941 (With A. M. B innie) A method of making stream-lines momentarily visible. Proc. Camb. phil. Soc. 37, 346.

1943 The colour of red blood corpuscles. Nature, Lond. 152, 476.1949 Wave-mechanical considerations applicable to fibre-forming substances. Fibre Sci. 130.1950 (With A. W. B irley) The vapour phase reaction between hydrazine and oxygen. Trans.

Faraday Soc. 47, 580.1958 David Leonard Chapman. Biogr. Mem. Fell. R. Soc. Lond. 4, 35.1960 (With S ir H arold H artley) The Right Reverend John Wilkins. In: The Royal Society, its

origins and founders (ed. Sir Harold Hartley). London: Royal Society.1965 Chemistry in Oxford. The development of the University laboratories. Chem. Br. 1, 517. 1967 Dalziel Llewellyn Hammick. Biogr. Mem. Fell. R. Soc. Lond. 13, 107.1970 The Balliol-Trinity laboratories. Notes Rec. R. Soc. Lond. 25, 227.1974 (With S. J. A ltmann) Charles Alfred Coulson. Biog. Mem. Fell. R. Soc. Lond. 20, 75.