380 CHEMICAL PROCESSES, CHAP. II. 



been precipitated. Thus the acid of Lemons, 

 Oranges, Gooseberries, and other fruits, may be 

 obtained in considerable purity, when the mucilage 

 that was mixed with them has subsided. And if 

 this method is not yet sufficient, recourse must 

 then be had to the additional aid of filtration, 

 which is one of the best and simplest means of 

 separating all such light and feculent, or oily and 

 resinous substances as may happen to make part of 

 the mixture. 



Such are some of the mechanical processes, 

 whether natural or artificial, which the experimen- 

 ter employs, or of which he avails himself, in the 

 analysis of vegetables, and by which a variety of 

 their ingredients may be obtained as they exist al- 

 ready formed in the vegetable. But there is also 

 a variety of other ingredients contained in the 

 vegetable subject, which do not exude spontane- 

 ously from the vessels containing them, and which 

 no process merely mechanical can reach. And 

 hence the necessity of chemical processes to com- 

 plete the analysis of the plant. 



CHAPTER II. 



CHEMICAL PROCESSES. 



THE chemical processes are such as are effected 

 by the agency of chemical powers, and may be re- 



