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ELEMENTS AND PROPERTIES OF VEGETABLE FOOD. 



A consideration of the nature, constituents and physiological effects 

 of vegetable food very naturally follows what has been said of the 

 organs, physiology, character, habits and location of plants in their 

 living state. The importance of plants to man, and all the graminivorous 

 animals depending alone on the vegetable kingdom for subsistence, and 

 the human family depending in turn on them for essential elements of 

 food, will readily be seen to present, in this connection, the most in- 

 teresting view of the vegetable kingdom. It is, indeed, for the nour- 

 ishment and very existence of man, and lower animals, that plants are 

 cultivated; in doing which the great body of mankind are employed, 

 and in which plants assume their chief interest. The relative amount 

 and qualities of the food which plants thus afford, constitute their rela- 

 tive value; and their properties and physiological effects in the ani- 

 mal economy should give to this branch of our subject deeper interest 

 than any other. It is, in fact, the final result or resolution of every 

 other into one, and an exposition of their ultimate utility, composition 

 and properties. In considering this concluding view of plants and 

 their relations to mankind, we shall be brief, as heretofore, however 

 extensively the subject deserves to be or has been treated by others. 

 Our object is to embody the most important truths known and recorded 

 in this department of our subject, without the ambition to start new 

 theories or controvert those established by the experiments and con- 

 clusions of others. 



All compound substances are composed of a greater or less number 

 of simple or ultimate elements. Of these there are 56 ; some of which, 

 variously combined, are the alimentary constituents of all food. Thus 

 composed, they form the proximate principles, in various proportions, 

 of all plants. All vegetable food, therefore, is resolvable into its 

 proximate or alimentary principles ; and these in turn, by analysis, 

 are divisible into simple or undecompounded elements. Thus wheat 

 is composed of fibrine, gelatine, albumen, &c., and these are composed 

 of the chemical elements carbon, hydrogen, oxygen, &c. 19 or 20 

 only of the simple elements have been found in organized, or animal 

 and vegetable bodies. The elements, therefore, of animal or vegeta- 

 ble bodies must be the constituents of their food. As 13 of these en- 

 ter into the composition of the human body, our food must be compos- 

 ed of the same number and kind of elements. These are carbon, hy- 

 drogen, oxygen, nitrogen, phosphorus, sulphur, iron, chlorine, calcium, 

 ) sodium, magnesia, potassium, and fluorine. Other substances be- 

 J come incidentally component parts of organized bodies, such as gold and 



