2
859 stimulation of the median nerve, which caused a tingling sensation only, causes a marked lowering of the threshold of both cutaneous and deep receptors. This is accompanied by cutaneous flushing in the area of the hand supplied by the median, being especially noticeable in the index finger and thenar eminence. Very strong faradic stimulation, which could only be borne for a moment or two and evoked vigorous muscular contractions, raises the threshold in both cutaneous and deep receptors. It is accom- panied by marked vaso-constriction in the palmar distribution of the median. The cutaneous receptors were excluded when necessary by freezing the skin with ethyl chloride. Faradic stimulation of the median nerve of a degree intermediate to the above caused a lowering of the threshold in the cutaneous receptors only. The changes were found to occur even if the circulation had been excluded for five to eight minutes, and therefore vascular change cannot be held to explain the sensory variation. Nor can changes in conductivity in the nerve fibres be held responsible for these results, because although strong currents may decrease conductivity, weak currents are not known to increase it. Observations on the contra- lateral side to that stimulated showed that during weak nerve stimulation there was a corresponding lowering of the threshold in the median and ulnar areas, which in some cases was associated with a flushing in the thenar region of the side stimulated and the opposite side. During very strong faradic stimulation the threshold was raised in both ulnar and median areas of the opposite side to that stimulated. The author concludes that the variations in the threshold of pressure pain caused by nerve stimulation are due principally to changes in the nerve cells with which the afferent fibres are connected. THE MEANING OF FEVER. LONG before the introduction of the clinical thermometer the meaning of fever was one of the most intriguing problems exercising the mind of the physician, and even when it became possible to measure degrees of pyrexia with accuracy but little light was thrown upon the matter. For many years a heightened temperature was regarded as evil in itself-very much as a heightened blood pressure quite usually is now-and in the treatment of febrile conditions the main line of attack was directed towards its reduction. Experience of antipyretic drugs led to some doubts as to the actual benefit to be expected from a mere lowering of temperature, and the pioneer experimental work of Rolly and Meltzerl showed that in infectious conditions some degree of pyrexia was certainly beneficial; the animals which they kept at fever heat were able to withstand infections fatal to normal controls. The light-hearted exhibition of antipyretics does not now hold a place in thera- peusis, nor is the degree of fever looked upon to any great extent as an index to the gravity of the condition; none the less the why and wherefore of fever 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 in two communications recently made to the Royal Society of Medicine. Working partly upon himself with typhoid vaccines and partly upon typhoid patients, Dr. Heath has been able to obtain results indicating in a very clear and unequivocal manner that the course of fever runs parallel to the reduction below normal of antibody in the blood. Thus, on administering subcutaneously to himself 2000 million killed 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 from Typhoid, Proc. Roy. Soc. Med. (S. Path.), 1924, xvii., 1-11. The Clinical Interpretation of Fever. A paper read to the Medical Section of the Royal Society of Medicine on March 25th, 1924. following the injection was associated with a restora- tion of the normal bactericidal power. Inoculation of doses of dead typhoid bacilli on ten successive days likewise produced irregular pyrexia, associated when 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 marked rise above the previous level of either the bactericidal or agglutinating power of the serum until about the tenth day. Dr. Heath suggests that an intensification of the experiment, by increasing the size and frequency of the doses, would have resulted in a continuous supernormal temperature and subnormal antibody titre, a condition which he believes to hold during the early days of a typhoid infection. Numerous other observations are recorded, all going to show that fever is always associated with a reduction below normal of antibody in the blood. This, in itself, is a valuable observation. Dr. Heath interprets his evidence to mean that this reduction of circulating antibody is the actual cause of fever, and that the heightened temperature may be looked upon as in the nature of a systemic reflex designed to speed up the production of more antibody to replace that used up. The teleological attitude in pathology is beset with pitfalls, but on the evidence Dr. Heath seems justified when he recommends that the use of antipyretic drugs for the cure of fever should be discontinued. ____ PERISTALSIS AND MENTAL DISORDER. IN the current issue of the British Journal of Radiology appears a short record by Drs. R. V. Stanford, Edwin Goodall, and Robert Knox of barium meal findings in 24 cases of mental disorder. The majority were recent cases and of a depressed type. As in a previous series published by these authors, the common findings were ptosis of the transverse colon, spastic contraction of the large bowel, and general stasis in the lower part of the intestinal tract. It is disappointing to find that the authors do not themselves comment on or analyse their results. Are these conditions of the intestinal tract to be regarded as a factor in the causation of insanity, or are they merely symptomatic ? This appears to be a difficulty which would still have to be faced, even were a really characteristic abnormality demonstrable in every case of a certain type of insanity. For example, it might be asked : Is the patient melancholic because he is constipated, or is he con- stipated because he has melancholia ? In a future communication from Cardiff Mental Hospital some answer to this question will be welcome. To return to the particular radiological findings, the abnorma- lities noted cannot be called characteristic ; anyone familiar with X ray reports knows that ptosis and stasis are unhappily common in subjects whose sanity has never been in question. ARTIFICIAL PNEUMOTHORAX STATISTICS. IT is doubtful if the combined statistical evidence of many workers is as valuable as that of a single worker or institution, even if the figures of the latter are comparatively small. But on behalf of pooled statistics it may be claimed that individual lack of judgment and excess of enthusiasm are less likely to obscure the issue than when we have to depend on one worker for all our information. The problem is much the same as that of choosing a milk-supply from one cow or a large herd ; if the one cow be diseased, it would be better for the consumer if he drew his milk-supply from a large herd with only one or two diseased cattle. A good sample of the large herd, or pooled statistics, is to be found in a paper by Dr. H. Maendl, of Grimmenstein,1 who has collected the experiences of his fellow workers in much the same way that Dr. L. S. T. Burrell and Dr. A. S. MacNalty collected, under the auspices of the Medical Research Council, the work done in this 1 Beiträge zur Klinik der Tuberkulose, 1924, lviii., 29.
