Temperature of the Human Body in Health. 197 



continuously, until it reached the lowest point of the night. In many 

 cases the evening fall had begun before the tea ; in one case only did it 

 rise after the meal, and on this occasion to the extent only of o, 2 Pahr., 

 and for a very short time. 



On these occasions, as the fall occurred immediately after, and not- 

 withstanding a hearty meal, and moreover as the boys were in all respects 

 placed in the same conditions throughout the day, it is obvious that we 

 must admit that there are certain circumstances irrespective of food 

 which determine the diurnal variation of the temperature. Is all this 

 fall due to these unknown circumstances ? Or must we admit that a 

 portion of the previous rise is due to the food, and as its heat-producing 

 effects wear off, and as the inanition period is reached, a fall takes place 

 equal in amount to the previous rise determined by the food ? 



We will now give reasons which lead us to conclude that the total of 

 the fall is due to circumstances wholly apart from the food. 



The question to decide is, how much of the evening fall is to be 

 accounted for by those circumstances (irrespective of food) that determine 

 the diurnal variation, and how much, if any, is due to the withdrawal of 

 the influence of food on the body. It must be evident that the fall 

 which occurred while the influence of the food was at its highest must be 

 wholly attributed to other circumstances. We need hardly dwell on this 

 point ; for if the fall is due to the diminished or exhausted influence of 

 the food, such a decline could not occur when the meal was exerting its 

 greatest effects ; therefore that part only of the fall which took place 

 when the effects of the meal had begun to diminish or had ceased can be 

 attributed to the withdrawal of the influence of food. But in all cases 

 the principal part of the evening fall occurred while the influence of the 

 tea must have been at its height, and in many instances the whole of this 

 fall had taken place at this time — the chief part of this evening fail 

 having on all occasions occurred before 11 p.m., and was, indeed, very 

 often by this time at the lowest point. Thus in those cases only where 

 the fall continued after 11 p.m., a very small portion, if any, of this fall 

 could be due to the declining influence of food. 



In this Table we give, in the first column the date, in the second the 

 amount of fall after 10 or 11 p.m., and in the third the hour of the night 

 when observations were discontinued. 



On the following days the boy took no bath 



Date. 

 Dec. 13 



„ 14 

 „ 15 

 „ 16 

 „ 29 

 2 

 6 



Jan. 



Amount of fall. 



No fall after 10 p.m. 



11 „ 

 10.30 „ 



A fall of 0°-4 after 10 „ 



No fall after 10 



10.30 „ 



A fall of 0°-8 after 11 „ 



Observation discontinued 

 at 12 p.m. 



12.15 

 through the night. 



