618 



with his dinner which was the real cause of the depression observed in Eng- 

 land. 1 



e. The influence of external temperature is sufficiently apparent in the ob- 

 servations already cited; for although external cold may act in a different de- 

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

 resistance, &c., yet there is ample proof that on the whole a continued exposure 

 to it reduces the temperature of the body somewhat below its ordinary standard, 

 whilst continued exposure to heat occasions a slight elevation in the temperature 

 of the body. The influence of cold is, of course, most powerfully exerted when 

 the body is at rest; and under such circumstances Dr. Davy found the tempera- 

 ture 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 individuals working in rooms of 

 various temperatures in the same factory, Dr. Davy found the tongue-thermo- 

 meter rise to 100 in one man, and to 100.5 in another, who had been working 

 for some hours in 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 tempera- 

 ture of 60. 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 (Op. cit.), that warm-blooded animals 

 are more speedily killed by extreme cold in summer than in winter; and it 

 seems probable, therefore, that we are partly to attribute the peculiar chilling 

 influence of a cold day in summer, and the oppressiveness of a warm day in 

 winter, to the seasonal change in the body itself; although the effect is doubt- 

 less referable in part to the effect of contrast upon our own feelings. 



652. The usual Temperature of the body occasionally undergoes consider- 

 able alteration in disease ; and this in the way either of increase or of diminu- 

 tion. Thus in maladies which involve an acceleration of pulse and a quickening 

 of the respiration, the temperature is generally higher than usual, even though 

 a large portion of the lung maybe unfit for its function. This is often remark- 

 ably seen in the last stages of phthisis, when the inspirations are extremely 

 rapid, and the pulse so quick as scarcely to admit of being counted ; the skin, in 

 such cases, often becomes almost painfully hot. On the other hand, in diseases 

 of the contrary character, such as " morbus cceruleus," asthma, and cholera, the 

 temperature of the body falls ; a reduction to 78 having been noticed in the 

 former maladies, and to 67 in the latter. The range observed by M. Andral 

 in diseases which less affected the calorifying function, was from 95 to 107.6; 

 and by M. Roger (loc. cit.), in diseases of children, from 74.3 to 108.5. Prof. 

 Dunglison 3 speaks of having seen the thermometer at 106 in scarlatina and 

 typhus ; and Dr. Francis Home 3 found it to stand at 104 in two individuals 

 in the cold stage of an intermittent, whilst it afterwards fell to 101, and subse- 

 quently to 99, during the sweating stage. Dr. Edwards mentions a case of 

 tetanus, in which the temperature of the body rose to HOf . The following 



1 This difference in effect noted by Dr. Davy, between a moderate quantity of wine 

 taken with dinner in England and in Barbadoes, seems readily explicable by the fact that 

 the presence of Alcohol in the blood diminishes for a time the energy of the proper com- 

 bustive process ( 264, A). For, when the temperature, of the atmosphere is considerably 

 below that of the body, this retardation of the combustive process occasioned by the wine 

 will allow the heat of the body to be lowered by it, notwithstanding the tendency to in- 

 creased activity of the circulation and respiration which the meal alone would exert. In 

 a warm climate, on the other hand, the cooling influence of the external air would not be 

 sufficient to produce this reduction in the temperature of the body, notwithstanding the 

 retarding influence of the wine upon the combustive process. 



2 "Human Physiology," 7th edit., vol. ii. p. 225. 



3 "Medical Facts and Experiments," London, 1759. 



