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VESTIGES OF THE 



the same four simple substances or elements — carbon, 

 oxygen, hydrogen, and nitrogen. The first combinations 

 of these in animals are into what are called proximate 

 principles, as albumen, fibrin, urea, allantoin, &c., out of 

 which the structure of the animal body is composed. 

 Now the chemist, by the association of two parts oxygen, 

 four hydrogen, two carbon, and two nitrogen, can make 

 urea. Allantoin has also been produced artificially. 

 Two of the proximate principles being realisable by 

 human care, the possibility of realising or forming all 

 is established. Thus the chemist may be said to have it 

 in his power to perform the first step in organisation.* 

 Indeed, it is fully acknowledged by Dr. Daubeny, that 

 in the combinations forming the proximate principles 

 there is no chemical peculiarity. " It is now certain," 

 he says, " that the same simple laws of composition per- 

 vade the whole creation ; and that, if the organic chemist 

 only takes the requisite precautions to avoid resolving 

 into their ultimate elements the proximate principles 

 upon which he operates, the result of his analysis will 

 show that they are combined precisely according to the 

 same plan as the elements of mineral bodies are known 

 to be."t A particular fact is here worthy of attention. 

 ''The conversion of fecula into sugar, as one of the 

 ordinary processes of vegetable economy, is efiected by 

 the production of a secretion termed diastase, which 

 occasions both the rupture of the starch vesicles, and 

 the change of their contained gum into sugar. This 

 diastase may be separately obtained by the chemist, and 



* Fatty matter has also been formed in the hiboratory. The pro- 

 cess consisted in passing a njixture of carbonic acid, pnre hydrogen, 

 and carburetted hydrogen, in the proportion of one measure of the 

 first, twenty of the second, and ten of the third, through a red-hot 

 tube. 



t " Supplement to the Atomic Theory." 



