530 EVOLUTION OF HEAT, LIGHT, AND ELECTRICITY. 



range of normal temperature in the axilla is from 97.25 Fahr. to 99.5 F., 

 and that the mean normal temperature is 98.6 F. The mean temperature 

 appears from Dr. Crombie's observations 1 to be a little higher in the natives 

 of India. It is also higher in Icelanders, 2 whilst it is as much as 2.5 F. 

 lower in Africans. 3 Sex and Pregnancy in women make no difference in 

 the mean temperature, though a slight augmentation of 0.3 F. is observed 

 during labor pains. Amongst the most important of these variations that 

 occur in the temperature of the body are those dependent upon Age, Period 

 of the day, Exercise or Repose, Ingestion of Food or Drink, and External 

 Temperature. 



i. The temperature of Infants just born, according to the observations of 

 Andrai, Dr. Davy, M. Roger, 4 and Dr. G. C. Holland, 5 is somewhat higher 

 than that of adults, 6 provided that they are placed in conditions favorable 

 to its sustenance; but, as will be shown hereafter, infants and young chil- 

 dren are very inferior to adults in their power of resisting the depressing 

 influence of external cold. Their temperature before birth is a trifle higher 

 than that of the mother's uterus or vagina. 7 When examined immediately 

 after birth by a thermometer in the axilla, it is nearly 100 ; but it quickly 

 (2 hours 8 ) falls to about 95.5, and gradually rises in the course of the next 

 twenty-four hours to about 97.7 in weakly subjects, and to 99.5 in strong 

 infants. Between four months and six years of age, M. Roger found the 

 average temperature to be 98.9 ; and, between six and fourteen years of 

 age, 99.16. Dr. Finlayson 9 stated that from 300 observations made on 

 children he had satisfied himself that in them there was a minimum from 

 about 10 P.M. to 3 A.M., a gradual rise during the early morning hours, a 

 maximum during the day, and a tolerably rapid fall during the early part 

 of the evening. The average range of temperature amounted to more than 

 3 Fahr., and this variation he believes cannot be explained by reference to 

 the diurnal range in the temperature of the air, to the influence of daylight, 

 of muscular exertion, of food, or of sleep, but is simply an expression of a 

 law of daily periodicity affecting the body. 10 The Temperature of aged per- 

 sons, from the observations of Dr. J. Davy, does not seem to be below that 

 of persons in the vigor of life, provided that there be no external depressing 

 influences; but they seem, like infants and young children, to have less 

 power of resisting external cold, the temperature of their bodies being more 

 easily and considerably reduced by it than is that of adults ; and hence 

 probably it has happened, that popular opinion assigns to them an habitually 

 inferior temperature. 



n. A slight diurnal variation in the temperature of the body appears 

 usually to take place, quite irrespectively of external heat or cold ; but this 

 does not seem to be very constant either in its period or its degree, and is 



1 Indian Annals of Med. Science, No. xxxii. 



: Thomson, Ueber Krankheiten auf Island, etc., p. 24. 



3 Livingstone, Travels in South Africa, p. 509. 



4 Archiv. Gen. de Mod , 1844. 5 Inquiry into the Laws of Life, 1829. 



6 Dr. 'W. F. Edwards (On the Influence of Physical Agents on Life, p. 115) gives 

 as the result of his observations, which were only ten in number, that tin' tempera- 

 ture of infants is lower than that stated above: but it is obvious that these observa- 

 tions were made during the period of depression which occurs in the first few days, 

 whilst the respiratory function is becoming established 



7 Barensprung, MUller's Archiv, 1851. See also And nil, Comptcs Rendus, t. Ixx, 

 1870, p. 82o. 



8 Dr. J. Maelagan, Transact. Roy. Soc. of Edinb , 1870; abstract in Lancet, Aug. 

 13th, 1870, p. '24:;. 



9 In a paper read before the Phil. Soc. of Glasgow. Dec. 3d, 1873. 



10 Sitz (jahrb. f. Kind.-heilk., Ed. 5v, 1871, p. 414) is in accord with Finlayson. 



