RELATION OF FOOD TO WORK, AND 271 



HIPPOCRATIC DOCTRINE OF INNATE HEAT. 



Hippocrates was well aware of tlie counectiou between food and 

 animal heat, although he erroneously regarded the animal heat as an 

 innate property of the body that caused an appetite for food, instead of 

 being itself produced by food; if we transpose his cause and effect, 

 mutatis mutandis, all his maxims as to animal heat are true. Thus, he 

 says : 



"Growing animals possess most innate heat, hence they require most 



food; but the old have least heat, and therefore require 



the least fuel." 



"The cavities of the body are naturally warmest in winter and spring; 



in these seasons therefore most food must be given ; and 



since there is more innate heat, more nourishment is required; as may 

 be seen in youths and athletes." 



These maxims, when translated into modern language, express the 

 well-known fact that the chemical changes of food that take place in 

 the body produce animal heat, and that the necessity for food to supply 

 mechanical work is greatest with the young and active, while the neces- 

 sity for the production of animal heat is greatest in the cold seasons of 

 the year. The direct connection of food with mechanical work is 

 expressed in the following maxims: 



"There should be no labor when there is hunger;" and its converse, 

 " Let labor precede meals." 



On principles such as those just given, the training of the athletes 

 was conducted ; and they were compelled to undergo a regular course, 

 commencing with blood-letting and active purgation, and consisting 

 of systematic muscular exercise suited to the nature of the contest in- 

 tended, accompanied by a dietary, of which the chief ingredients consisted 

 of biscuits and pigs' kidneys, washed down by a minimum of water. It 

 is truly not much. to be wondered at that those who survived the train- 

 ing were formidable in the boxing-ring or race-course. 



The relation of animal heat to respiration is referred to by Hippocrates 

 in a remarkable maxim : 



"Those persons have the loudest voices who Lave most [innate] 

 heat, for they inspire the largest quantities of the cold air; and the pro- 

 duct of two great quantities must be itself great." 



Galen believed the heart to be the center of "innate heat," but he was 

 well aware that increase or diminution of respiration caused increase or 

 diminution of heat, and was intimately connected with it. Thus he sajs: 



" Since, therefore, the heart is, as it were, the hearth and fountain of 

 the innate heat with which the animal is pervaded," &c. 



"The necessity for respiration is the greatest and most imperious 

 guard of the innate heat." 



" Those persons in whom the innate heat has been much cooled breathe 

 but little and slowly." 



