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stimulation of the median nerve, which caused atingling sensation only, causes a marked lowering ofthe threshold of both cutaneous and deep receptors.This is accompanied by cutaneous flushing in thearea of the hand supplied by the median, beingespecially noticeable in the index finger and thenareminence. Very strong faradic stimulation, whichcould only be borne for a moment or two and evokedvigorous muscular contractions, raises the thresholdin both cutaneous and deep receptors. It is accom-panied by marked vaso-constriction in the palmardistribution of the median. The cutaneous receptorswere excluded when necessary by freezing the skinwith ethyl chloride. Faradic stimulation of themedian nerve of a degree intermediate to the abovecaused a lowering of the threshold in the cutaneousreceptors only. The changes were found to occureven if the circulation had been excluded for five toeight minutes, and therefore vascular change cannotbe held to explain the sensory variation. Nor canchanges in conductivity in the nerve fibres be heldresponsible for these results, because although strongcurrents may decrease conductivity, weak currents arenot known to increase it. Observations on the contra-lateral side to that stimulated showed that during weaknerve stimulation there was a corresponding loweringof the threshold in the median and ulnar areas, whichin some cases was associated with a flushing in thethenar region of the side stimulated and the oppositeside. During very strong faradic stimulation thethreshold was raised in both ulnar and median areasof the opposite side to that stimulated. The authorconcludes that the variations in the threshold ofpressure pain caused by nerve stimulation are dueprincipally to changes in the nerve cells with whichthe afferent fibres are connected.

THE MEANING OF FEVER.

LONG before the introduction of the clinicalthermometer the meaning of fever was one of themost intriguing problems exercising the mind of thephysician, and even when it became possible tomeasure degrees of pyrexia with accuracy but littlelight was thrown upon the matter. For many yearsa heightened temperature was regarded as evil in

itself-very much as a heightened blood pressurequite usually is now-and in the treatment of febrileconditions the main line of attack was directed towardsits reduction. Experience of antipyretic drugs ledto some doubts as to the actual benefit to be expectedfrom a mere lowering of temperature, and the pioneerexperimental work of Rolly and Meltzerl showedthat in infectious conditions some degree of pyrexiawas certainly beneficial; the animals which theykept at fever heat were able to withstand infectionsfatal to normal controls. The light-hearted exhibitionof antipyretics does not now hold a place in thera-peusis, nor is the degree of fever looked upon toany great extent as an index to the gravity of thecondition; none the less the why and wherefore offever remains almost as much a mystery as ever.Some little light has been thrown upon at least

one aspect of the subject by Dr. Oliver Heath2 intwo communications recently made to the RoyalSociety of Medicine. Working partly upon himselfwith typhoid vaccines and partly upon typhoidpatients, Dr. Heath has been able to obtain resultsindicating in a very clear and unequivocal mannerthat the course of fever runs parallel to the reductionbelow normal of antibody in the blood. Thus, onadministering subcutaneously to himself 2000 millionkilled typhoid bacilli, he found that a rise of tempera-ture to 100° F. was synchronous with a very consider-able drop in the bactericidal power of his blood ;the return of the temperature to normal on the day

Rolly and Meltzer : Deutsch. Arch. f. Klin. Med., 1908,xciv., 335.

2 Heath, Oliver: The Meaning of Fever, illustrated fromTyphoid, Proc. Roy. Soc. Med. (S. Path.), 1924, xvii., 1-11. TheClinical Interpretation of Fever. A paper read to the MedicalSection of the Royal Society of Medicine on March 25th, 1924.

following the injection was associated with a restora-tion of the normal bactericidal power. Inoculationof doses of dead typhoid bacilli on ten successivedays likewise produced irregular pyrexia, associatedwhen the dose was sufficiently large with a demon-strable fall in the bactericidal titre of the serum ;as in clinical typhoid fever there was no markedrise above the previous level of either the bactericidalor agglutinating power of the serum until about thetenth day. Dr. Heath suggests that an intensificationof the experiment, by increasing the size and frequencyof the doses, would have resulted in a continuoussupernormal temperature and subnormal antibodytitre, a condition which he believes to hold during theearly days of a typhoid infection.Numerous other observations are recorded, all

going to show that fever is always associated with areduction below normal of antibody in the blood.This, in itself, is a valuable observation. Dr. Heathinterprets his evidence to mean that this reductionof circulating antibody is the actual cause of fever,and that the heightened temperature may be lookedupon as in the nature of a systemic reflex designed tospeed up the production of more antibody to replacethat used up. The teleological attitude in pathologyis beset with pitfalls, but on the evidence Dr. Heathseems justified when he recommends that the use ofantipyretic drugs for the cure of fever should bediscontinued.

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PERISTALSIS AND MENTAL DISORDER.

IN the current issue of the British Journal ofRadiology appears a short record by Drs. R. V.Stanford, Edwin Goodall, and Robert Knox ofbarium meal findings in 24 cases of mental disorder.The majority were recent cases and of a depressedtype. As in a previous series published by theseauthors, the common findings were ptosis of thetransverse colon, spastic contraction of the largebowel, and general stasis in the lower part of theintestinal tract. It is disappointing to find that theauthors do not themselves comment on or analysetheir results. Are these conditions of the intestinaltract to be regarded as a factor in the causation ofinsanity, or are they merely symptomatic ? Thisappears to be a difficulty which would still have to befaced, even were a really characteristic abnormalitydemonstrable in every case of a certain type of insanity.For example, it might be asked : Is the patientmelancholic because he is constipated, or is he con-stipated because he has melancholia ? In a futurecommunication from Cardiff Mental Hospital someanswer to this question will be welcome. To returnto the particular radiological findings, the abnorma-lities noted cannot be called characteristic ; anyonefamiliar with X ray reports knows that ptosis andstasis are unhappily common in subjects whosesanity has never been in question.

ARTIFICIAL PNEUMOTHORAX STATISTICS.

IT is doubtful if the combined statistical evidenceof many workers is as valuable as that of a singleworker or institution, even if the figures of the latterare comparatively small. But on behalf of pooledstatistics it may be claimed that individual lack ofjudgment and excess of enthusiasm are less likely toobscure the issue than when we have to depend onone worker for all our information. The problem ismuch the same as that of choosing a milk-supplyfrom one cow or a large herd ; if the one cow bediseased, it would be better for the consumer if hedrew his milk-supply from a large herd with onlyone or two diseased cattle. A good sample of thelarge herd, or pooled statistics, is to be found in apaper by Dr. H. Maendl, of Grimmenstein,1 who hascollected the experiences of his fellow workers inmuch the same way that Dr. L. S. T. Burrell andDr. A. S. MacNalty collected, under the auspices ofthe Medical Research Council, the work done in this

1 Beiträge zur Klinik der Tuberkulose, 1924, lviii., 29.