Temperature of the Human Body in Health. 195 



from which we now draw our conclusions will be found in full at the 

 end of the sections treating of the temperature of health, and on the 

 influence of baths on the heat of the body. 



We hope to show the high probability that the diurnal variation of the 

 temperature is altogether independent of food ; and, while attempting to 

 establish this, we shall speak first of the influence of breakfast, secondly 

 of the tea, and lastly of the dinner. 



Concerning the behaviour of the temperature before and after break- 

 fast, it may be stated that these boys took breakfast at 6 a.m., dinner 

 at 12, and tea at 5 p.m. — no food being allowed at other times, with one 

 exception, which at the proper place will be noted and referred to. 



Is the daily rise of the body temperature clue to food ? During the 

 early morning hours, before breakfast, the temperature rose considerably ; 

 indeed rather more than half the diurnal rise took place before 6 a.m., 

 the breakfast time of these lads, showing that some of this rise is not 

 due to food. This part of the rise, it must be apparent, could not 

 be produced by food, unless, indeed, it be attributed to the tea of the 

 previous evening, a supposition impossible to maintain, as ten hours 

 elapsed between the tea and the beginning of the morning rise. The 

 chief influence of a meal on the body is expended during the third to 

 the fifth hour, and then gradually declines and usually ceases altogether 

 in ten hours, a fact shown by the variations in the urea of the urine 

 after a meal. During the three first hours the quantity of urea gradually 

 increases, then for an hour or more the maximum quantity is maintained, 

 after which it gradually grows less, till the standard of inanition is 

 reached. 



Now in all our observations during the early hours of the evening, 

 when the influence of the evening meal was greatest, the temperature 

 fell considerably, and the rise of temperature did not begin till the effects 

 of food must have entirely ceased. 



We are thus driven to admit that half the daily rise is due to other 

 causes than food. 



The annexed Table gives a summary of the observations elsewhere 

 recorded in detail, and includes the whole of the morning rise, which was 

 always accomplished by 9 a.m. 



The first column gives the name of the lad ; the second the hours 

 before breakfast during which the temperature rose ; the third the rise 

 before breakfast ; the fourth the hourly rise ; the fifth the hours of 

 observation after breakfast ; the sixth the rise during this time ; the 

 seventh the hourly rise after breakfast ; and the last column gives the 

 food taken during the investigation. 



