ORGANIC CHEMISTRY. 15 



is adequate to the complete renovation of every portion of 

 the living fabric.* 



Imperfect as is our knowledge of organic chemistry, we 

 see enough to convince us that a series of the most refined 

 and artificial operations is required, in order to bring about 

 the complicated and elaborate arrangements of elements 

 which constitute both animal and vegetable products. Thus, 

 in the very outset of this, as of every other inquiry in Phy- 

 siology, we meet with evidences of profound intention and 

 consummate art, infinitely surpassing not only the power and 

 resources, but even the imagination of man. 



Much as the elaborate and harmonious mechanism of an 

 animal body is fitted to excite our admiration, there can be 

 no doubt that a more extended knowledge of that series of 

 subtle processes, consisting of chemical combinations and de- 

 compositions which are continually going on in the organic 

 laboratory of living beings, would reveal still greater won- 

 ders, and would fill us with a more fervent admiration of 

 the infinite art and prescience which are even now manifest- 

 ed to us in every department both of the vegetable and ani- 

 mal economy. 



The processes by which all these important purposes are 

 fulfilled, comprise a distinct class of functions, the final ob- 

 ject of which may be termed Nutrition, that is, the repara- 

 tion of the waste of the substance of the organs, their main- 

 tenance in the state fitting them for the exercise of their 

 respective offices, and the application of properly prepared 

 materials to their development and growth. 



The functions subservient to nutrition may be distinguished 

 according as the processes they comprise relate to seven 

 principal periods in the natural orders of their succession. 

 The first series of processes has for its objects the reception 

 of the materials from without, and their preparation and 

 gradual conversion into proper nutriment, that is, into mat- 

 ter having the same chemical properties with the substance 



* See the article " AGE " in the Cyclopaedia of Practical Medicine, where 

 I have enlarged upon this subject. 



