438 POPULAR SCIENCE MONTHLY. 



of the very old is higher than the middle-aged. The infant at 

 birth has a temperature of 99° F. to 100° F., and it maintains 

 a temperature of 99° F. and upward for several days. The varia- 

 tions of temperature from other causes are much greater in chil- 

 dren than in adults, as also the normal daily variations of tem- 

 perature. About the sixtieth year the average temperature of 

 man begins to rise, and approximates that of the infant. In the 

 young and old the " heat-regulating power " is more readily ex- 

 hausted, and hence continued high temperature is far more fatal to 

 these classes. 



The first noticeable fact in regard to bodily temperature in dis- 

 ease is that there are daily fluctuations as in health, but much more 

 extreme. In general, the remission of temperature in disease occurs 

 in the morning, and the exacerbation in the afternoon and evening; 

 the minimum is reached between six and nine o'clock in the morning, 

 and the maximum between three and six o'clock in the evening:. In 

 many diseases the minimum temperature is not below 100° F., and 

 usually it is one or two degrees above that point, while the maximum 

 has no definite limit and may reach the dangerous height of 107° F. 

 It should be noticed tliat the highest daily temperature in disease, as 

 in health, occurs in the afternoon, when the temperature of the air 

 in summer is the greatest. 



The conditions affecting the temperature of the body other than 

 those due to physiological conditions are very numerous. First and 

 most obvious is the temperature of the surrounding atmosphere. It 

 is a well-established fact that an average temperature of the air of 

 54° F. is best adapted to the public health, for at that temperature 

 the decomposition of animal and vegetable matter is slight, and nor- 

 mal temperature is most easily maintained. Every degree of tem- 

 perature above or below that point requires a more or less effort 

 of the heat-regulating power to maintain the proper equilibrium. 

 Even more potent in elevating the bodily temperature is the intro- 

 duction into the blood, whether by respiration or by direct injection, 

 of putrid fluids and the gases of decomposing matters. If this in- 

 jection is repeated at short intervals, death will occur with a high 

 temperature. The air of cities contains emanations, in hot weather, 

 from a vast number of sources of animal and vegetable decomposi- 

 tion, and the inhalation of air so vitiated brings in contact with the 

 blood these deleterious products in a highly divided state which 

 cause a fatal elevation of temperature in the young, old, and en- 

 feebled. The same effect is produced by the air in close and heated 

 places, as in tenement houses, workshops, schoolhouses, hospital 

 wards, and other rooms where many persons congregate for hours. 

 Air thus charged with poisonous gases becomes more dangerous if 



