ORGANIC CHEMISTRY. O 



is a problem which has hitherto baffled all the 

 efforts of philosophy. Chemistry, notwithstanding 

 the proud rank it justly holds among the physical 

 sciences, and the noble discoveries with which it 

 has enriched the arts; notwithstanding it has un- 

 veiled to us many of the secret operations of nature, 

 and placed in our hands some of her most powerful 

 instruments for acting upon matter; and notwith- 

 standing it is armed with full powers to destroy, can- 

 not, in any one organic product, rejoin that which 

 has been once dissevered. Through the medium of 

 chemistry we are enabled, perhaps, to form some 

 estimate of the value of what we find executed by 

 other agencies ; but the imitation of the model, even 

 in the smallest part, is far beyond our power. 

 No means which the laboratory can supply, no pro- 

 cesses which the most inventive chemist can devise 

 have ever yet approached those delicate and refined 

 operations which nature silently conducts in the 

 organized texture of living plants and animals. 

 The elements of organic substances are not very 



I numerous ; the principal of them being oxygen, 

 carbon, hydrogen, nitrogen, sulphur, and phospho- 

 rus, together with a few of the alkaline, earthy, and 

 metallic bases. These substances are variously 



I united, so as to form certain specific compounds, 

 which although they are susceptible, in different 



I instances, of endless modifications, yet possess such 

 a general character of uniformity, as to allow of 

 their being arranged in certain classes ; the most 

 characteristic substance in each class constituting 

 what is called a proximate organic principle. Thus 

 in the vegetable kingdom we have Lignin, Tannin, 

 Mucilage, Oil, Sugar, Fecula, &c. The animal 



