INFLUENCE OF EXTERNAL TEMPERATURE. 



813 



show that the effect of tropical heat is to raise the mean temperature 

 of the human body, but the increase is generally less than one degree. 

 Crombie 1 found, as the result of 1288 observations upon himself, that 

 the temperature of the mouth was about 0'23 higher in Bengal than the 

 average in England, but the difference was greater during the first few 

 weeks of residence in the hot climate. 



On the other hand, some observers maintain that residence in a 

 tropical climate does not raise the temperature of the body; thus 

 Boileau 2 states that the normal axillary temperature is between 367 

 and 37'2, Thornley 3 and Furnell 4 that it is invariably the same as in 

 England, 36'9. 



Numerous careful observations recently made by Neuhauss 5 during a 

 voyage round the world, show the effect of external heat upon the daily 

 temperature, pulse, and discharge of urine. The following are some of the 

 results : 



The influence of the different seasons of the year No marked 

 effect upon the heat of the body can be ascribed to the different seasons 

 of the year, apart from that due to variations in external temperature. 

 The numerous observations made by Davy 6 upon himself tend to show 

 that the temperature of the mouth is somewhat lower during the winter 

 months in England, and slightly higher during the summer ; a similar 

 series taken in the tropics, in Barbadoes, where the mean annual 

 temperature of the air is 267, and the range throughout the year is 

 about 8, sho\vs no marked variation during the different seasons. 



Jousset 7 found that the cool season caused a fall of two- or three- 

 tenths of a degree in the average temperature of natives of the tropics. 



From Bosanquet's 8 observations of the rectal temperature, it appears 

 that the highest sustained average temperature occurred in the winter 

 and early spring months. These determinations were made upon 

 himself four times a day for a period of three years. 



A few observations have been made on the influence of winter and 

 summer upon the temperature of animals. Thus Edwards 9 found in 

 the case of sparrows that the mean temperature rose progressively from 



1 Indian Ann. Med. Sc., Calcutta, 1873, vol. xvi. p. 550. 



2 Lancet, London, 1878, vol. i. p. 413. 



3 Ibid., 1878, vol. i. p. 554. 



5 Virchoiv's Archiv, 1893, Bd. cxxxiv. S. 365. 



6 Phil. Trans., London, 1845, pt. 2, p. 319 ; and 1850, p. 437. 



7 Arch, de med. nav., Paris, 1883, tome xl. p. 124. 



8 Lancet, London, 1895, vol. i. p. 672. 



9 "Animal Heat," in Todd's " Cyclopedia, " vol. ii. p. 659. 



4 Ibid., 1878, vol. ii. p. 110. 



