935

thoracic wall against the whole area of the diaphragm.In the case of the bell stethoscope, the higher-frequencyresponse obtained by pressure is presumably due to

stretching of the soft tissues per se.We may conclude that unless the diaphragm endpiece

is being used merely to hear something from a chest wallemaciated in such a way as to make it impossible for abell to lie flat, it should always be pressed down firmly ;otherwise its object will be defeated.With regard to the flexible tubes of a stethoscope,

there seems to be no virtue in a very large internaldiameter. However, there are two reasons why thetubes should have thick walls. First, the instrumentmust be robust ; and second, the thicker and less resilientthe wall, the less extraneous noise will be heard. Apartfrom the room noise heard from ill-fitting earpieces, mostnoise comes in via the fairly extensive

" membrane "

of the flexible tubes. There is thus a distinct advantagein making the wall as thick and stiff as possible, and it isfor this reason that tough plastic tubes may have a goodclaim for consideration.

It would be interesting to know if any of yourreaders can make any addition to, or comment on, thisanalysis.

University College Hospital,London, W.C.1.

C. J. DICKINSON.

TYPHOID FEVER IN A GENERAL HOSPITAL

SIR,-In his letter of Dec. 2, Dr. Grant takes twoworkers to task for treating a case of typhoid fever ina large general hospital. In your issue of Dec. 16,Dr. Michael Curtin, registrar in the hospital for infectiousdiseases of which Dr. Grant is medical superintendent,describes a case of subacute bacterial endocarditis treatedthere for five months. Is it partly because the beds inisolation hospitals are being used for non-contagiousconditions that the failure to find accommodationfor pulmonary tuberculosis has become a " nationalscandal" ?

’

Newcastle upon Tyde. H. A. DEWAR.

TOWARDS SAFER MILK

SIR,-Your annotation of Oct. 7, describing the areaeradication scheme for dealing with tuberculosis in cattle,says :

" Immediate slaughter of all reactors is not feasible,because it would cause a disastrous fall in milk-suppliesand serious disturbance of farm economy ; the cow playsan important part in maintaining soil fertility, and somereplacement stock must be bred from the tuberculin-

positive." This complacent condonation of the use of reactor cows

for liquid milk production rests on two false premises.First, farmers are really worried about the flooding ofthe liquid-milk market, and it is common knowledgethat much milk from attested herds goes to the manu-

facturing market. The fear of a milk famine is thereforeridiculous ; and even if such a fear was justified I amsure few mothers would not welcome a return to rationingrather than subject their children to the risk of tubercu-losis. Secondly, it is nonsense to fear the lowering ofsoil fertility through the lack of cowdung. Many farmscarry no livestock at all, and a simple alteration of soilmanagement would obviate any loss of fertility due tothe absence of dung.The Government’s proposal to compensate farmers for

the slaughter of reactors is a scandal, since the bestfarmers have already cleaned up their herds and onlythe sluggards or the unscrupulous continue the productionof milk from reactors. Reactor cows still form the back-bone of the business of a type of dealer and farmer whoshould never be allowed to handle human food (exceptfor their own use). I have personal knowledge of such a

man who keeps a tuberculin-tested cow for his own useand sells milk from a cheap herd of reactors.

If every reactor cow was suitably branded, farmerswould not dare to keep them openly, and the waiting-lists for sanatorium treatment would be lessened byremoval of all cases of bovine tuberculosis.

Llandinam, Mont. HARDY NAYLOR.

** We have long urged that all except the highestgrade of designated milk should be heat-treated beforedistribution. Though, oii the present policy, eradicationof tuberculosis in cattle will not be achieved for somethinglike fifteen years, this is a shorter time than othercountries have taken over the task. Payment of com-pensation to farmers who would otherwise be deprivedof their livelihood seems to us essential.—ED. L.

TROPHIC AND TROPIC

SIR,—In " thyrotropic " and kindred words the

adjective &tgr;&rgr;&pgr;&khgr;&sfgr; forming the suffix is derived from thepassive voice of the verb &tgr;&rgr;&pgr;∈&ngr;, which has the twomeanings of to

" turn oneself towards " and to " betakeoneself to."

&pgr; &dgr;&thgr;’ &tgr;&lgr;µ&ohgr;&ngr; &tgr;&rgr;&psgr;µ&agr;; &tgr;&ngr;&sfgr; &xgr;&ngr;&ohgr;&ngr;&dgr;µ&ugr;&sfgr; &sgr;∈µ &tgr;&dgr;’ &pgr;’ &agr;&tgr;&agr; &phgr;&ugr;&ggr;&ngr;;

Eur. Hipp.Where shall I turn me ? Think. To what friend’s doorBetake me, banished on a charge so sore ?

Gilbert Murray.

The heliotrope turns itself towards the sun : the

thyrotropic hormone betakes itself to the gland. Forthe use compare the well-known epithet of Odysseus,&pgr;&lgr;&tgr;&rgr;&pgr;&sfgr; (polutropos), " versatile " ; or the nameof the Fate’ ’A&tgr;&rgr;&pgr;&sfgr; (whence atropine), " Inexorable."To say that a hormone betakes itself anywhere is notprecisely accurate, but it is an allowable figure of speech :in fact it is a trope.

’

Professor Burn’s substitution (Dec. 9) of trophic fortropic, from &tgr;&rgr;&phgr;∈&ngr; to rear, will hardly do, for thenotion of nourishment is implied, whereas a hormonestimulates growth without contributing nourishment.An adjective denoting " furthering growth " is &bgr;&lgr;&agr;&tgr;&khgr;&sfgr;(blastikos).

"

Thyroblastic "

proclaims in one word that"it exerts a most important influence on the develop-ment of the thyroid gland."

Orpington, Kent. H. ST. H. VERTUE.

SIR,—May I venture to question Professor Burn’sassertions on the meaning of the suffix " tropic."The verb &tgr;&rgr;&pgr;∈&ngr;, from which &tgr;&rgr;&pgr;&sfgr; is derived

is a transitive verb (Latin : vertere), not intransitiveas implied by Professor Burn. Admittedly, used inthe middle voice it carries the meaning which heattributes to it, but basically it means "’ to turn (some-thing), guide, or direct." In the spirit of free translationso common in scientific terms, " adrenotropic " and"

thyrotropic" can quite legitimately be interpretedas

"

guiding or directing the adrenal or thyroid," a

more accurate description of the action of these hormonesthan " nourishing," which function they obviously donot perform.

Etymologically, ,.

geotropic" and ’’

heliotropic ’’ can

be regarded as implying that the earth and sun

respectively are responsible for the directing or are

themselves being directed. Although the scientistsmay not mean this, it would be folly for us to base theapplication of this and other suffixes of classical originupon existing inaccurate English usage.

Sheffield. H. H. PILLING.