86 ALIMENTATION. 



Preparation of Animal Articles of Food. 



The preparation of food by cooking is designed to disin- 

 tegrate its tissue, to develop flavors which will be agreeable 

 to the taste and stimulate the secretion of the digestive fluids, 

 and to prepare the alimentary principles so that they may 

 be readily separated, liquefied, and finally absorbed. Many 

 of the culinary processes accomplish these ends, but others 

 are eminently unphysiological. Fortunately the latter, as the 

 rule, do not render the food more agreeable to the palate. 



One of the most important questions, in a chemico-phys- 

 iological point of view, connected with the preparation of 

 animal food, is with regard to the principles which are ex- 

 tracted from the various meats by prolonged boiling in water : 

 for this is the mode of cooking which is frequently employed 

 in hospitals and other institutions where it is desirable to pre- 

 sent in the articles of diet an exact amount of nutritive ma- 

 terial. This important subject has been investigated by the 

 many eminent physiologists and physiological chemists, 

 among whom may be mentioned as most conspicuous, Ma 

 gendie, Chevreul, Liebig, and Payen. 



By subjecting meat to prolonged and gentle ebullition in 

 water, certain principles are volatilized and given ofi*. These 

 are ammonia in small quantity, an odorous principle pecu- 

 liar to the kind of meat used, and certain volatile acid prin- 

 ciples. Certain of the constituents of the meat may be dis- 

 solved by maceration in cold water, and quite a number of 

 organic principles are dissolved by boiling. While it must 

 be acknowledged that the concentrated animal broths present 

 a considerable amount of nutritive material in a condition in 

 which it is very easily digested, chemical analysis shows such 

 a small proportion of solid matter that we are surprised that 

 they possess so much nutritive power. Soup ordinarily con- 

 tains a small quantity of gelatine, formed by a transforma- 

 tion and solution of some of the organic matter of the bones 

 and the fibrous tissue, creatine, an organic nitrogenized mat- 



