220 BOARD OF AGRICULTURE. 



It is to be noted that reparative and building material can not alone be termed 

 food, for that term must include also all substances necessary to the maintenance 

 of vital processes. According to this conception, then, the air we breathe is as 

 much a food as the bread we eat. The waier we drink undergoes no digestive pro- 

 cess, but is simply absorbed into the body unchanged. It is present in every part, 

 yet can hardly be considered a tissue-forming material, being rather a medium for 

 carrying building material, and also for carrying away waste. 



Water, however, is a food, as it is necessary to maintain vital processes. 



Some foods are very rich in nutritive qualities, and there are still others that 

 increase vital action in a degree far beyond the amount of nutritive material which 

 they supply. Some foods are identical with certain structures of the body, and, 

 being introduced, may be incorporated with little or no change. Illustrative of 

 this class is the mineral matter, necessary for the growth of bony structure, and 

 water, the general necessity. 



Some foods are valuable, not bo much because they are very nutritious, but be- 

 cause they are easily and quickly changed into the substances of the body; or 

 again,- because they act quickly in sustaining the vital functions; such are classed 

 as easily digested and assimilated foods. 



Foods are animal and vegetable; is a classification of general character, but 

 can not be considered by the chemist, because vegetable and animal matter are 

 similar in chemical composition, an indissoluble bond seemingly existing. Plants 

 derive their curbon from the air by decomposing carbonic acid gas, which has been 

 supplied to the air by the lungs of animals. Mineral matter, water and nitrogen, 

 plants derive from mother earth, the nitrogen proceeding from animal sources. 



The animal consumes the plant, and after its material has served to build, re- 

 pair and sustain, he gives it to nature to be used over again for plant food. Thus 

 there is an unbroken circle in the production of food from difTerent sources. All 

 vegetables contain water and mineral matter ; so do meats of all kinds. 



The solid carbon and the gasses hydrogen, oxygen and nitrogen, make up the 

 major composition of foods. 



Flesh has for its base of construction fibrine; vegetables lignine, two substances 

 almost exactly alike in chemical composition, subserving like purposes. Albumen 

 is found alike in vegetable and animal foods. Thus may be traced the similarities 

 of the.se two. 



Most foods require more or less preparation before they are fit to be eaten. 

 Cooking is an art as old as history, and yet, although of the greatest importance 

 and worthy of the attention of the best minds, comparatively no scientific study 

 has been made of it. Cooking is intrusted to that class in society ksown as ser- 

 vants, and, as is well known, tiiey do not possess high intelligence. 



The gastrouomic wurld is cognizant of the names of numberless famous cooks, 

 but the whole list probably contaias only a very few who had the slightest idea of 

 the changts efi'ected by heat on food materials. They only knew heat to be a 

 means for the accomplishment of an end, but an intelligent understanding was far 

 from them. 



Count Eumford's labors in the art of cooking are well known, and the great 

 Liebi^'s studies in the name line are of inestimable worth. 



