1153

THE LANCET.

LONDON : SATURDAY, JUNE 10, 1922.

Health and Efficiency in the PotteryIndustry.

HEALTH AND EFFICIENCY IN THE POTTERY INDUSTRY.

THE application of physiological knowledge to

industrial processes continues to be extended by theIndustrial Fatigue Research Board, in the interestsof those employed. The latest instance is to be found

in an investigation carried out in earthenware andchina factories. 1 The ware is first modelled from

damp clay in potters’ shops, which communicate

directly with heated stoves where this " green "

ware is placed to dry before being passed on to beburnt in kilns. Prolonged controversy, which hasengaged the attention of Departmental Committeesand H.M. Inspectors of Factories, has centred on

complaints that the hygiene of potters’ shops is

deleteriously affected by back draughts of hot andmoist air escaping from the stoves into the work-rooms. The object of the inquiry now reportedupon was to investigate the physiological aspect ofthis problem. Although no general agreement existsas to the most suitable temperatures for industrialwork, previous inquiries of the Board have providedobservations made in the boot and shoe trade, in

weaving sheds, and in engineering factories, which

may usefully be compared with the extensive datanow presented.

Dr. H. M. VERNON and ’Mr. T. BEDFORD, jointauthors of the first part of the report, which dealswith atmospheric conditions in potters’ shops, pointout that the work of the potter is continuouslyactive, but not heavy. They suggest 62’5° F. as

an ideal temperature for the work ; and hold thatthis temperature can be maintained when outdoortemperature is low and need only be exceeded onwarm days. A temperature curve representing a

practical ideal according to outdoor conditions is

given. Systematic investigation in potters’ shopsdisclosed that conditions varied with the type of

drying stove used ; leaf and draw-out stoves gavean average excess of temperature of 7° over thatfound in an engineering workshop which approxi-mated to the ideal ; dobbin stoves gave an excessof 6° ; chamber stoves came nearer to the ideal;while some cabinet stoves gave good and othersinferior results. On the whole, the contention thatthe air of potters’ shops is unduly warm was cor-roborated. Contrary to expectation, however, theair in potters’ shops was not found to have a greaterrelative humidity than that of engineering shops, orof boot and shoe factories, or, indeed, of outside airat similar dry-bulb temperature; though, havingregard to the high temperatures met with, the abso-lute amount of moisture present was greater. It

1 Two Investigations in Potters’ Shops. By H. M. Vernon,assisted by T. Bedford. Industrial Fatigue Research Board.Report No. 18. Pp. 74. 1922. Price 2s. 6d.

is now established that while temperature and mois-ture are important, the cooling power of air, whichis a function of rate of movement as well as of warmthand humidity, is the physiologically importantmatter. The (median) velocity of the air currents inpotters’ shops was found to be 17 ft. per minute inwinter and 21 ft. in summer, whilst that in boot andshoe shops was 35 and 37 ft. respectively, or nearlydouble as much. Thus the cooling power of the air,as estimated by the kata-thermometer, is only 5’6and 4-5 on an average for winter and summer obser-vations respectively : whereas in boot and shoe

shops it is 7-4 and 6-4. A matter of some interestnot previously investigated is raised here : the authorspoint out that the movements of the workers them-selves in carrying out industrial operations mustbe added to the velocity of the air in order to arriveat the cooling power of the atmosphere to which

they are exposed ; and that, within certain limits,the more an operative moves in the course of hiswork, the less should he notice whether a workshopis well or badly ventilated. If these movements are

unduly active, heat due to increased metabolism

may outweigh the increased cooling power, but undernormal conditions in a quiet atmosphere an advan-tageous stimulus may in this way accrue to the workers.(Is this an explanation of why many brain-workerswhen dictating walk the office noor ?) In this inquiry,however, as the movements’of the potters do notexceed those of workers in other industries cited-

they fall short of the movements of mule-spinners incotton-mills-the comparisons made are not invali-dated. The evidence collected shows that potters’shops in general are kept at a considerably highertemperature than that considered suitable to otherindustries which require work of a correspondingdegree of activity on the part of the operatives.This excess of heat is dependent largely on the faultystructure of the drying stoves, though potters them-selves are to some extent responsible. They are

careless about keeping the stove doors shut, as wellas being indolent about opening windows. Nearlyall the windows were found shut until the shoptemperature reached 67° to 7 0°, in spite of the factthat the windows, being usually of the hopper type,caused no direct draughts when in the half-openposition. Even at a temperature of 80° only two-thirds of the available window space was kept open.The reason given is that potters have, for the mostpart, been engaged in the industry since the age of14, and they have got so acclimatised to the heatthat they feel uncomfortable without it. The result,however, must manifest itself in lower basal meta-bolism, and a greater liability to respiratory affections ;and the suggestion is made that herein may be foundan influence, secondary to exposure to pottery dust,contributing to the high mortality from phthisisand respiratory diseases experienced in the potteryindustry.The second part of the report, written by

Dr. VERNON alone, deals with the efficiency of varioustypes of drying stoves. It is somewhat technical,and its main interest is the rehabilitation of the old

theory, that in the drying of ware of moderate sizehigh temperature is the chief requisite. He furtherholds that mechanical efficiency coupled with thebest workshop conditions for human efficiency, canbe attained only by preventing nearly all back draught,and by installing an independent system of warmingthe shops. The whole report, which is an excellentone, establishes yet again that there is rarely anyincompatibility between conditions advantageous fortechnical and for hygienic efficiency.

1154 RECENT WORK ON YELLOW FEVER.

Recent Work on Yellow Fever.IT is a little over 50 years since OBERMEIER made an

important contribution to medical science by thediscovery of the spirochæte of relapsing fever, but ithas been left until now for success to be obtained inthe exploration of the group to which his organismbelonged and the recognition of other importantpathogenic species. The attack upon the spirochsetedates from SCHAUDINN’s demonstration of the

Treponema pallidum in 1905, and since then rat-bitefever and Weil’s disease have each been traced tocausal organisms within this group. Few scientistshave contributed more to the solution of the diffi-culties which beset this branch of bacteriology thanhas NOGUCHI, and it is fitting that the most recentlydiscovered pathogenic member of the spirochætalgroup should have been brought to light throughhis efforts. The previous workers upon the problemof yellow fever, pursuing their subject in the dark,but yet with most admirable logic, had greatlynarrowed the field of inquiry. The organism wasunknown, but its habits were recognised ; the con-ditions of its transmission by the Stegomyia mosquitowere exactly worked out, its filtrability was proven,and conjectures were freely hazarded, by the lateSir PATRICK MANSON amongst others, as to itsprotozoal nature. The numerous claimants for thepathogenic role in this disease had been separatelyinvestigated by STERNBERG and rejected. In a word,the properties of the germ were to a large extentknown, but it had never been seen.

This was the position when HIDEYO NOGUCHI, whohas summarised the history of investigations on

yellow fever in an admirable contribution to the

Congress of the Royal Institute of Public Health, justconcluded, commenced his investigations at Guayaquilas a member of the Yellow Fever Commission ofthe International Health Board. He examined a

large number of cases diagnosed as yellow fever,and systematic attempts to infect animals of manyspecies were made on an extensive scale. Success

<only attended his efforts in the case of the guinea-pig,where, out of 74 animals inoculated with the bloodobtained during the first week of the disease, eight,representing material derived from seven cases ofthe malady, acquired a disease characterised by arise of temperature four or five days after inoculation,followed by jaundice a few days later, and often

ending in death. In the organs of the first animalwhich succumbed to the disease NoGUCHi 1 wasable to detect a spirochsete, and in further experi-mental infections, obtained both by passage fromanimal to animal and by the inoculation of humanmaterial, this organism was constantly found wheresymptoms of the disease developed. Further, culturalmethods, akin to those devised by this author forthe cultivation of the spirochaetes of syphilis andinfective jaundice, gave positive results, not onlywhen the material used for inoculation came fromthe infected animals, but also in a number of humancases, in some of which it was also possible to demon-strate the organism in the blood by use of the dark-ground condenser. This organism, which NoGucHihas termed the Leptospira icteroides, very closelyTesembles the Leptospira icteroh&oelig;morrhagica of infec-tive jaundice, and it was necessary to show thatthe two were not identical, and that the diseasein Guayaquil was in fact yellow fever and not

spirochaetal jaundice. This would appear to be

1 Noguchi : Etiology of Yellow Fever, Journal of Experi-mental Medicine, vol. xxix., No. 6, 1919, and succeedingnumbers.

proved by a number of points in the behaviourof the organism in the animal body. For example,the urine in Weil’s disease has been found to berich in spiroch&aelig;tes in the early days of convalescence,whilst the Leptospira icteroides is hardly seen in theurine, which is usually non-infective. Further,the latter organism disappears from the tissues ofthe moribund animal, and in this it also contrastswith the Leptospira icteroh&oelig;morrhagica, which wouldappear to be a much more resistant organism. Immu-

nologically, moreover, the two organisms appeardistinct, agglutination and the Pfeiffer phenomenondifferentiating them, whilst recovery from theone, consequent upon a non-fatal attack, does notconfer resistance towards infection with the other ;although here the distinction is less absolute. It isconcluded that, although not identical, the two

organisms are closely related, as, in fact, are theclinical conditions to which they give rise.With regard to the further agreement of the

characters of this organism with the previouslydetermined facts about the nature of the yellowfever virus, it has been found that the organismwill pass through Berkefeld filters, the filtrates

being infective although showing no visible organisms.This observation has raised again the interestingquestion of the existence of a granular infective

phase in the life-history of the spirochaete ; a phasewhich LEISHMAN2 believes that he has observedin relapsing fever, and ANDREW BALFOUR 3 has upheldin the spiroch&oelig;tosis of fowls. Some experimentsdirected towards the transmission of yellow feverto animals by the Stegomyia mosquito were successful.In one case it was possible to infect guinea-pigs bythe bites of mosquitoes previously fed on patientsill with the disease, and in another to transmit thedisease from guinea-pig to guinea-pig by this means.In this connexion .the interesting observation wasmade that the latent period of 12 days, which mustelapse before the mosquito fed upon human-infectedblood becomes virulent, is shortened to eight daysin the case in which the insect feeds on the animal.What happens in the body of the mosquito is stillan unsolved mystery; but NOGUCHI utilises thisfact to suggest that, since the infection in the animalis a much heavier one, the shortened latent periodwould point towards a simple pullulation of the

organisms, which requires to reach a certain con-centration before the inoculation effected at bitingis heavy enough to cause infection-a presumptionagainst the existence of a special developmentalcycle in the insect’s body.

"Brain.", A WIDELY representative gathering of Britishneurologists assembled on May 26th to do honour toDr. HENRY HEAD on the occasion of his retiring fromthe editorship of Brain, a position which he hasoccupied for some 17 years. The veteran Sir DAVIDFERRIER, one of the founders and original editors ofthe journal, which is now half a century old, washappily able to attend and by his presence to form aliving link between the old era and the new ; Dr.PERCY SMITH, too, on whose shoulders the editorialburden had fallen in somewhat difficult times, Dr.GORDON HoLMES, who succeeds Dr. HEAD inthe editorial chair, and many others who at one timeor another have acted on the committee of Brain,

2 Leishman : Mechanism of Infection in Tick Fever andHereditary Transmission of Spiroch&aelig;ta Duttoni in the Tick,Trans. Soc. Trop. Med. Hyg., London, 1910, vol. iii., p. 77.

3 Balfour : Spiroch&aelig;tosis of Sudanese Fowls, Fourth Reportof Wellcome Research Laboratories, Khartoum, 1911, p. 76.