EVOLUTION OF HEAT. 533 



pression did not occur. Drs. Ringer and Rickards 1 have shown that, except- 

 ing in those who are much accustomed to its use, the ingestion of alcohol in 

 considerable doses causes, a remarkable diminution of temperature, amount- 

 ing in some cases to about 3 Fahr. In rabbits, the injection of alcohol into 

 the rectum caused a depression of the animal heat amounting to 15. They 

 found that alcohol in various doses produces only slight and temporary de- 

 pression of the temperature of febrile persons; and consequently that although 

 when indicated, it will act to some extent beneficially iu virtue of its power- 

 to cause some diminution of the temperature, yet it cannot bring the tem- 

 perature of febrile persons to that of health. The experiments of Dr. W. 

 Ogle, 2 and of Tscheschichin, 3 are confirmatory of the preceding results. Dr. 

 Ogle found that tea caused an elevation of temperature. Common experience 

 leads to the conclusion, that after a meal, as after exercise, there is greater 

 warmth in the extremities; but Dr. Davy's observations show that, in his 

 own person, whilst resident in England, there was usually an appreciable 

 depression immediately after dinner, though in Barbadoes the effect of a 

 moderate meal was to produce an elevation. In both cases, however, Dr. 

 Davy observed that the ingestion of wine had a positively depressing influ- 

 ence on the temperature of the body, which increased with the quantity 

 taken ; and it may have been the constant employment of wine with his 

 dinner, which was the real cause of the depression observed in England. 



v. The influence of external temperature is sufficiently apparent in the 

 observations already cited ; for although external cold may act in a different 

 degree on different individuals, according to their respective ages, powers of 

 resistance, etc., sometimes, when its action is brief, causing a slight increase 

 of temperature, yet there is ample proof that on the whole a continued ex- 

 posure to it reduces the temperature of the body somewhat below its ordinary 

 standard, whilst continued exposure to heat occasions a slight elevation iu 

 the temperature of the body. The influence of cold is, of course, most pow- 

 erfully exerted when the body is at rest ; and under such circumstances Dr. 

 Davy found the temperature of his own body to be reduced, on an average 

 of four observations, to 96.7, the average temperature of the surrounding 

 air having been 37. On comparing the bodily temperature of different in- 

 dividuals working in rooms of various temperatures in the same factory. Dr. 

 Davy found the tongue thermometer rise to 100 in one man, and to 100.5 

 in another who had been working for some hours iu a room at 92 ; whilst 

 it was 99 in a young woman who worked in a room at 73, and only 97.5 

 in another who worked in a temperature of 60. Dr. Schuster 4 found the 

 effects of baths of different kinds, as hot water and douche baths, was to 

 cause an elevation of temperature, and to increase the rapidity of the pulse. 

 Horvath, in experiments on rabbits, found that when they are cooled dowu 

 by snow to 73 F. the heart beats rarely, excitation of the vagus is inopera- 

 tive, the intestines are motionless and non-excitable, asphyxiation causes 

 neither augmentation of the blood-pressure nor cramps, but all these phe- 

 nomena are reversed when the temperature is raised to 100 Fahr. 5 The 

 lowest temperature to which Horvath 6 succeeded in cooling puppies with 

 subsequent restoration was 40 Fahr. as measured by a thermometer in the 

 rectum. The effects of seasonal change are less marked in Man, than they 

 are in the lower animals, which are more exposed to extremes of temperature ; 

 but it seems principally exerted in modifying the heat-producing power. 

 For it has been shown by Dr. W. F. Edwards, that warm-blooded animals 



1 Proceed, of the Roy. Med.-Chir. Soc., vol. v, 1866, p. 209. 



2 Op. cit., p. 238. 8 Reichert's Archiv, 1866, p. 151. 

 Virchow's Archiv, Bd. xliii, p. 60, 1868. 



5 Horvuth, Wien. Akadem., 1870, No. 11. 6 Centralblatt, 1871, p. 513. 



