154 THE CANADIAN NATURALIST. [Vol. vi. 



purely negative testimony, of whicli we have now so much against 

 it, throw himself into the inquiry. Such investigations as those 

 of Pasteur, Pouchet and Bastian are among the most interesting 

 and momentous in the whole range of natural history ; and their 

 results, whether positive or negative, 'must richly reward the most 

 careful and laborious experimenting." The consideration of the 

 finest discoverable structures of the organised parts of living bodies 

 is intimately bound up with that of their chemical composition 

 and properties. The progress which has been made in organic 

 chemistry belongs not only to the knowledge of the composition 

 of the constituents of organised bodies, but also in the manner 

 in which that composition is chemically viewed. Its peculiar 

 feature, especially as related to biological investigation, consists 

 in the results of the introduction of the synthetic method of re- 

 search, which has enabled the chemist to imitate or to form artifi 

 cially a greater and greater number of the organic compounds. 

 In 1828 the first of these substances was formed by Wohler, 

 by a synthetic process, as cyanate of ammonia ; and still, though 

 some no doubt entertained juster views, the opinion prevailed 

 among chemists and physiologists that there was some great and 

 fundamental difference in the chemical phenomena and laws of 

 organic and inorganic nature. But now this supposed barrier has 

 been in a great measure broken down and removed, and chemists, 

 with almost one accord, regard the laws of combination of the 

 elements as essentially the same in both classes of bodies, what- 

 ever differences may exist in actual composition, or in the reaction 

 of organic bodies in the more complex and often obscure condi- 

 tions vitality, as compared with the simpler and, on the whole, 

 better known phenomena of a chemical nature observed in the 

 mineral kingdom. Thus, by the synthetic method, there have 

 been formed among the simpler organic compounds a great num- 

 ber of alcohols, hydrocarbons, and fatty acids. But the most re- 

 markable example of the synthetic formation of an organic com- 

 pound is that of the alkaloid conia, as recently obtained by Hugo 

 Schiffby certain reactions from butyric aldehyde, itself an artificial 

 product. This substance, so formed, and its compounds, possess 

 all the properties of the natural conia — chemical, physical, and 

 physiological — being equally poisonous with it. The colouring- 

 matter of madder, or alizarine, is another organic compound which 

 has been formed by artifical processes. It is true that the organ- 

 ised or containing solid, either of vegetable or animal bodies, has 



