512 NUTRITION. 



being from V to 11 per hour. Death usually occurred when the diminution had 

 amounted to about 30. 



When the surrounding conditions call for the development of an unusual amount of 

 heat, the diet is always modified, both as regards the quantity and kind of food ; but 

 when food is taken in sufficient quantity and is of a kind capable 'of maintaining proper 

 nutrition, its composition does not affect the general temperature. If we were to adopt 

 without reserve the view that the non-nitrogenized alimentary principles are the sole 

 agents in the production of heat, we should certainly be able to determine either an 

 increase in the animal heat or a greater loss of heat from the surface, in persons partak- 

 ing largely of this kind of food. This, however, has not been shown to be true ; and the 

 temperature of the body seems to be uniform in the same climate, even in persons living 

 upon entirely different kinds of food. The elaborate observations of Dr. Davy are very 

 conclusive upon this point : " The similarity of temperature in different races of men is the 

 more remarkable, since between several of them whose temperatures agreed, there was 

 nothing in common but the air they breathed some feeding on animal food almost 

 entirely, as the Vaida others chiefly on vegetable diet, as the priests of Boodho and 

 others, as Europeans and Africans, on neither exclusively, but on a mixture of both." 

 Nevertheless, the conditions of external temperature have a remarkable influence upon the 

 diet. It is well known, for example, that, in the heat of summer, the amount of meats 

 and fat taken is relatively small, and the succulent, fresh vegetables and fruits, large, as 

 compared with the diet in the winter. But although the proportion of starchy matters in 

 many of the fresh vegetables used during a short season of the year is not large, these 

 articles are equally deficient in nitrogenized matter. During the winter, the ordinary 

 diet, composed of meat, fat, bread, potatoes, etc., contains a large amount of nitrogenized 

 substance, as well as a considerable proportion of the hydro-carbons ; and, in the sum- 

 mer, we instinctively reduce the proportion of both of these varieties of principles, the 

 more succulent articles taking their place. This is even more strikingly illustrated by a 

 comparison of the diet in the torrid or temperate and in the frigid zone. Under the head 

 of alimentation, we have already noted the prodigious quantities of food consumed in the 

 Arctic regions and the effect of the continued cold upon the habits of diet of persons 

 accustomed to a temperate climate. It is stated, upon undoubted authority, that the daily 

 ration of the Esquimaux is from twelve to fifteen pounds of meat, about one-third of 

 which is fat. Dr. Hayes, the Arctic explorer, noted that, with a temperature ranging 

 from 60 to 70, there was a continual craving for a strong, animal diet, particularly 

 fatty substances. Some of the members of the party were in the habit of drinking the 

 contents of the oil-kettle with evident relish. 



Under such conditions as those which surround inhabitants of temperate regions, in 

 passing into the frigid zones a change in diet is imperatively demanded, in order to keep 

 the animal temperature at the proper standard ; but, when the climate is changed from 

 the temperate to the torrid, the habits of life frequently remain the same. It is a pretty 

 general opinion among physicians who have studied the subject specially, that many of 

 the peculiar disorders that affect those who have changed their residence from a temper- 

 ate to a very warm climate are due, in a great measure, to the fact that the diet and hab- 

 its of life are unchanged. 



The influence of alcoholic beverages upon the animal temperature has been studied 

 chiefly with reference to the question of their use in enabling the system to resist exces- 

 sive cold. We have already discussed somewhat fully the physiological effects of alcohol, 

 and we have seen that its use does not enable men to endure a very low temperature for 

 a great length of time. This is the universal testimony of scientific Arctic explorers ; and 

 Dr. Hayes particularly states, that, " in almost any shape, it is not only completely 

 useless, but positively injurious." 



The relations of animal heat to respiration and nutrition constitute a most interesting 

 and important division of the subject, which will be more fully considered in discussing 



