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 
from 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 
of 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. 
