ON ORGANIC CHEMISTRY. 47 



These two bodies contain in all seven elements, amongst which sulphur, phos- 

 phorus and nitrogen are found ; they contain also the earth of bones. The 

 serum holds in solution common salt and other salts of potash and soda, of 

 which the acids are carbonic, phosphoric, and sulphuric acids. Serum when 

 heated coagulates into a white mass called albumen. This substance, along 

 with fibrine, constitutes the globules of blood, along with a red colouring 

 matter in which iron is a constituent. 



Analysis has shown the singular result, that fibrine and albumen are per- 

 fectly identical in chemical composition. The arrangement of their particles 

 is different, as the variation in their forms proves, and their composition in 

 100 parts is exactly the same. They may be mutually converted into each 

 other. In the process of nutrition both may be converted into muscular 

 fibre, and that in return into blood. 



All organized parts of the body, i. e. parts possessed of a decided shape, 

 contain nitrogen. The principal ingredients of blood contain 1 7 per cent, of 

 nitrogen, and there is no part of an active organ which contains less than 17 

 per cent, of this element. 



The nutritive process is simplest in the case of the carnivora. This class 

 of animals lives on the blood and flesh of the graminivora ; but this blood 

 and flesh is identical with their own. The nutriment of carnivora is derived 

 originally from blood, and on the entrance of the nutriment into their system 

 it is again converted into blood. "With the exception of hair, horn, hoof and 

 feathers, every part of a graminivorous animal is susceptible of assimilation. 

 In a chemical sense, therefore, it may be considered that a carnivorous 

 animal in taking food feeds upon itself, for its nutriment is identical in com- 

 position with its own tissues. 



But at first sight the nutritive process of graminivorous animals seems al- 

 together different ; their digestive apparatus is less simple, and their food 

 contains very little nitrogen. From what constituents of vegetables is their 

 blood produced ? 



All vegetables contain nitrogenized compounds, and the most ordinary ex- 

 perience shows us, that the greater the quantity of these compounds which 

 are in the food, the less is the quantity of food required for the purposes of 

 nutrition. The nitrogenized compounds of vegetables are called vegetable 

 fibrine, vegetable albumen, and vegetable casein. Vegetable fibrine is fami- 

 liarly known as gluten ; vegetable albumen is obtained from decoctions of 

 the juice of nutritious vegetables, such as cauliflowers, asparagus and man- 

 gel-wurzel ; vegetable casein is principally found in leguminous seeds, such as 

 peas, beans, and lentils. 



These three compounds are the only nitrogenized bodies which form food 

 for graminivorous animals, for all others existing in plants are rejected from 

 the system. 



Now analysis has led to the interesting result that they are exactly of the 

 same composition in 100 parts ; and, what is still more extraordinary, that they 

 are absolutely identical with the chief constituents of the blood — animal fibrine 

 and animal albumen. By identity, be it remarked, we do not imply similarity, 

 but absolute identity even, as far as their inorganic constituents are concerned. 



How beautifully simple, then, by the aid of these discoveries, does nutrition 

 appear ! Those vegetable constituents which are used by animals to form 

 blood, contain the essential ingredients of blood ready formed. In point of 

 fact, then, vegetables produce in their organism the blood of all animals ; for 

 the carnivora, in consuming the blood and flesh of the graminivora, consume, 

 strictly speaking, the vegetable principles which have served for the nourish- 

 ment of the latter. In this sense, we may say that the animal organism gives 



