502 NUTRITION. 



the destruction of non-nitrogenized matters may be, it is certain that the fat stored up in 

 the body is consumed, when there is a deficiency in any of the elements of food, as well 

 as that which is taken into the alimentary canal. It is rendered probable, indeed, by the 

 few experiments that have been made upon the subject, that obesity increases the power 

 of resistance to inanition. At all events, in starvation, the fatty constituents of the body 

 are the first to be consumed, and they almost entirely disappear before death. As we 

 have already seen, sugar is never deposited in any part of the organism, and it is merely a 

 temporary constituent of the blood. If the sugars and fats have, in certain regards, simi- 

 lar functions in nutrition, and if, in addition to the mechanical functions of fat, it may 

 be retained in the organism for use under extraordinary conditions, it becomes very 

 important to ascertain the mechanism of its production and deposition. 



The production of fatty matter by certain insects, in excess of the fat supplied with 

 the food, was established long ago by the researches of Huber ; and analogous observa- 

 tions have been made upon birds and mammals by Boussingault. Some of the experi- 

 ments of Boussingault are peculiarly interesting, as they were made upon pigs, in which 

 the digestive apparatus closely resembles that of the human subject. They showed con- 

 clusively that, under certain circumstances, more fat exists in the bodies of animals than 

 can be accounted for by the total amount of fat taken as food added to the fat existing 

 at birth. In some very interesting experiments with reference to the influence of different 

 kinds of food upon the development of fat, it was ascertained that fat could be produced 

 in animals upon a regimen, sufficiently nitrogenized, but deprived of fatty matters ; but 

 the fact should be recognized that " the nutriment which produces the most rapid and 

 pronounced fattening is precisely that which joins to the proper proportion of albuminoid 

 substances the greatest proportion of fatty principles." 



Animals cannot be fattened without a certain variety in the regimen. We have 

 already discussed the necessity of a varied diet and have shown that an animal will die 

 of starvation when confined exclusively to one class of principles, even if this be of the 

 most nutritious character ; and it is not necessary to refer again to the experiments which 

 have demonstrated that a diet confined exclusively to starch, sugar, or fat, or even pure 

 albumen or fibrin, cannot sustain life, much less fatten an animal. We are prepared, 

 then, to understand why, in the pigs experimented upon by Boussingault, a regimen con- 

 fined to potatoes did not prove to be fattening, notwithstanding the large proportion of 

 starch, and that fat was produced in abundance only when the food presented the proper 

 variety of principles. 



Very little is known concerning the precise mechanism of the production of fat. The 

 experiments of Boussingault seem to leave no doubt that it may be formed from any kind 

 of food, even when the alimentation is exclusively nitrogenized ; but it is, nevertheless, a 

 matter of common observation that certain articles of diet are more favorable to its 

 deposition than others ; and it is also true that the herbivora are fattened much more 

 readily, as a rule, than the carnivora. 



Theoretical considerations would immediately point to starch and sugar as the ele- 

 ments of food most easily convertible into fat, as they contain the same elements, though 

 in different proportions ; and it is more than probable that this view is correct. It is said 

 that, in sugar-growing sections, during the period of grinding the cane, the laborers be- 

 come excessively fat, from eating large quantities of the saccharine matter. We cannot 

 refer to any exact scientific observations upon this point, but the fact is pretty generally 

 admitted by physiologists. Again, it has been frequently a matter of individual experience 

 that sugar and starch are favorable to the deposition of fat, especially when there is a 

 constitutional tendency to obesity. A most remarkable example of this, and one which 

 has met with considerable notoriety, is worthy of mention, though not reported by a 

 scientific observer. We refer to the letter on corpulence, by Mr. Banting. The writer 

 of this curious pamphlet, in 1862, was sixty-six years old, five feet and five inches in 

 height, and weighed two hundred and two pounds. Under the advice of Mr. William 



