ORGANIC CHEMISTRY 



ITS APPLICATIOK TO 



VEGETABLE PHYSIOLOGY AND AGRICULTURE. 



THE object of Chemistry is to examine 

 'nto the composition of the numerous modifi- 

 cations of matter which occur in the organic 

 and inorganic kingdoms of nature, and to 

 investigate the laws by which the combina- 

 tion and decomposition of their parts is 

 effected. 



Although material substances assume a 

 vast variety of forms, yet chemists have not 

 been able to detect more than fifty-five 

 bodies which are simple, or contain only 

 one kind of matter, and from these all other 

 substances are produced. They are con- 

 sidered simple only because it has not been 

 proved that they consist of two or more 

 parts. The greater number of the elements 

 occur in the inorganic kingdom. Four only 

 are found in organic matter. 



But it is evident that this limit to their 

 number must render it more difficult to as- 

 certain the precise circumstances under 

 which their union is effected, and the laws 

 which regulate their combinations. Hence 

 chemists have only lately turned their at- 

 tention to the study of the nature of bodies 

 generated by organized beings. A few 

 years have, ^however, sufficed to throw 

 much light upon this interesting depart- 

 ment of science, and numerous facts have 

 been discovered which cannot fail to be 

 of importance in their practical applica- 

 tions. 



The peculiar object of organic chemistry 

 is to discover the chemical conditions essen- 

 tial to the life and perfect development of 

 animals and vegetables, and generally to in- 

 vestigate all those processes of organic 

 nature which are due to the operation of 

 chemical laws. Now, the continued exist- 

 ence of all living beings is dependent on the 

 reception by them of certain substances, 

 which are applied to the nutrition of their 

 frame. An inquiry, therefore, into the con- 

 ditions on which the life and growth of 

 living beings depend, involves the study of 

 those substances which serve them as nutri- 

 ment, as well as the investigation of the 

 sources whence these substances are derived, 

 2 



and the changes which they undergo in the 

 prpcess of assimilation. 



LA beautiful connection subsists between 

 the organic and inorganic kingdoms of na- 

 ture. Inorganic matter affords food to 

 plants, and they, on the other hand, yield 

 the means of subsistence to animals. The 

 conditions necessary for animal and veget- 

 able nutrition are essentially different. An 

 animal requires for its development, and fo? 

 the sustenance of its vital functions, a cer- 

 tain class of substances which can only be 

 generated by organic beings possessed of 

 life. Although many animals are entirely 

 carnivorous, yet their primary nutriment 

 must be derived from plants ; for the animals 

 upon which they subsist receive their nour- 

 ishment from vegetable matter. But plants 

 find new nutritive material only in inorganic 

 substances. Hence one great end of veget- 

 able life is to generate matter adapted for 

 the nutrition of animals out of inorganic 

 substances, which are not fitted for this pur- 

 pose. Now the purport of this work is, to 

 elucidate the chemical processes engaged in 

 the nutrition of vegetables.! 



The first part of it will be devoted to the 

 examination of the matters which supply 

 the nutriment of plants, and of the changes 

 which these matters undergo in the living 

 organism. The chemical compounds which 

 afford to plants their principal constituents, 

 viz., carbon and nitrogen, will here come 

 under consideration, as well as the relations 

 in which the vital functions of vegetables 

 stand to those of the animal economy and to 

 other phenomena of nature. 



The second part of the work will treat of 

 the chemical processes which effect the 

 complete destruction of plants and animals 

 after death, such as the peculiar modes of 

 decomposition, usually described asfermen* 

 tation, putrefaction, and decay; and in this 

 part the changes which organic substances 

 undergo in their conversion into inorganic 

 compounds, as well as the causes which 

 determine these changes, will become matter 

 of inquiry. 



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