

PLANT ANALYSIS AS AN APPLIED SCIENCE 177 



do better than read it. The attention of the reader is directed 

 to the great number of species of plants which occur in na- 

 ture, to the great abundance and variety of their chemical 

 constituents, and to the circumstance that almost every skill- 

 ful analysis of a plant that has not been examined yields new 

 hitherto unknown products. The difficulties of plant analysis 

 are pointed out, but it should be the effort of future investi- 

 gators to endeavor to overcome these difficulties, when the 

 importance of plant chemistry is considered in relation to 

 scientific botany and chemistry, medicine, pharmacy, dietetics, 

 agriculture, etc. The author says that the analysis of plants 

 in one respect possesses an advantage over the analysis of min- 

 erals, 1 and in that respect can often be made more complete 

 than that of a mineral. 



It would not be possible within the space of an hour to give 

 an accurate description of how to analyze a plant, and the many 

 methods which may be followed. I can give an idea of how to 

 follow the scheme of which I have spoken as being the most 

 complete, and the practical application of some facts derived 

 ylrom plant analysis. 



/ The specimens which are presented for analysis should be in 

 good condition and well selected as typical of the genus or 

 species. In case of comparative studies the time of year of the 

 gathering should be noted. All foreign substances and dust 

 should be removed, and care taken not to displace parts of 

 the specimens. 



All plants are chemically composed of two classes of sub- 

 stances, and on incineration one class is decomposed into gases 

 and the other class forms the ash constituents. These two 

 divisions of the plant's constituents are known as the volatile 

 and fixed parts. The manner of proceeding with an analysis of 

 a plant is somewhat different in the case of fresh plants and those 

 which are air-dried. Fruits and succulent plants and fleshy roots 

 may sometimes be examined with advantage in the fresh con- 

 dition, especially if they contain much saccharine material 

 or volatile products. Generally the parts of plants to be used 

 for analysis are dried at a temperature under 30 C., or air- 



1 Plant Analysis, English translation, p. 2. 



