MODERN CHEMISTRY. 451 



utmost power, to record the results derived from this great 

 scheme of systematic enquiry. 



While still compelled to limit ourselves to a mere outline 

 of these methods and results, we must briefly notice their 

 connection with those discoveries of Liebig in animal and 

 vegetable chemistry, which have received such important 

 application to physiology, medicine, agriculture, and other 

 arts of life. These applications (in which, as well as in 

 the labours that led to them, the names of other enquirers 

 are largely associated) give to the subject of organic che- 

 mistry its peculiar colouring and character. It is a science 

 eminently practical in relation to the physical interests and 

 necessities of man. In analysing and otherwise examining 

 the various solids and fluids which enter into the fabric of 

 animal life and in submitting to similar experiment the 

 ingesta of aliment and air which minister to its growth and 

 preservation, and the egesta which provide for the perpetual 

 and necessary change of parts this branch of Chemistry 

 becomes a main pillar of physiology, and offers the fairest 

 hope we can entertain of raising medicine to the rank of the 

 more exact sciences.* While by researches of equal exact- 

 ness, directed to vegetable substances ; and to those elements 

 in the atmosphere, in soils, and in manures, which serve to 

 their nutriment and various properties, agriculture is made 

 to assume the character of a science, and Man obtains new 

 and more definite dominion over that earth on which it is his 

 destiny to labour for existence. 



All alimentary substances, in fact, whatever their nature, 



* "We may take as one instance of these refined analyses, that of coffee by 

 Payen, who, in this familiar berry, discovers and denotes ten different ingre- 

 dients, all existing in determinate proportions. Caffein itself (the ingredient 

 which gives its peculiar property to coffee) is a compound of the four great 

 organic elements in fixed proportions, and its chemical relations to other bodies 

 offer some of those complex names in which Chemistry abounds Dimethyl- 

 alloxantin, Caffeo-murexid, &c. 



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