PLANT ANALYSIS AS AN APPLIED SCIENCE 181 
ALCOHOL EXTRACT 
Tannic acids; bitter principles; organic acids; alkaloids; 
glucosides; glucose; saccharose; coloring-matters; resins. 
WATER EXTRACT 
Mucilaginous and albuminous substances; dextrin and 
other carbohydrates; saponin and allied compounds; glucoses; 
saccharoses; organic and mineral acids. 
DILUTE SODA EXTRACT 
Metarabic acid; albuminous substances; phlobaphenes, 
etc. 
DILUTE HYDROCHLORIC ACID EXTRACT 
Parabin; oxalate of calcium, etc.; starch. 
DETERMINATION OF LIGNIN AND ALLIED SUBSTANCES AND 
OF CELLULOSE 
Benzole, chloroform, amyl alcohol, and acetic ether are 
frequently valuable solvents for certain extractions, although 
they are not included in the general scheme. 
Dragendorff recommends the maceration to be conducted 
at the ordinary temperature, but a fixed oil, if present, may 
be extracted more readily by exhaustion at an elevated tem¬ 
perature. Such substances as caoutchouc may be readily 
extracted by boiling chloroform or bisulphide of carbon. If 
a known volume of the extract is evaporated, the residue will 
yield an approximate result of the amount of definite sub¬ 
stances obtained in the plant. 
In my own work, I have usually found it convenient to take 
about twenty grams of the powdered plant and exhaust them 
in a displacement apparatus. There are some advantages for 
this method, in a preliminary study of the plant. The time 
necessary for the exhaustion is very much lessened; from 
ten to twelve hours at the most is ample time to allow the 
apparatus to run with each solvent, if the solvents are kept at 
