1 
INTRODUCTION. 
ions, of colloidal metals, with an action analogous to that of 
ferments, and of known and unknown physical properties, such 
as radio-activity, probably enter into the action of many 
drugs. All the phenomena of plant life are not explicable in 
terms of chemistry and physics ; there are certain residual 
phenomena which point to the existence of what may be called 
in the present state of our knowledge, “ vital force.” 0 
It is hence, that many medical practitioners have been 
disappointed with tinctures and other preparations of medicinal 
plants, because such preparations did not give any satisfactory 
results when prescribed to patients. Speaking of Oolut-Kumhal, 
(Abroma augusta) Dr. Bhoobun Mohun Sirkar wrote in the 
Indian Medical Gazette for May, 1900 : — 
“ Attempts have been made to administer the drug in the 
more acceptable forms of tincture, pill or powder, but none prove 
so efficacious as the fresh viscid sap in substance in which form 
I have used it with wonderful results.” 
It is well-known that the people of India use the juice of fresh 
vegetables for medicinal purposes. But on chemical analysis, 
these vegetables do not yield any peculiar chemical substances to 
which their curative virtues could be justly attributed. It has 
been the tendency of late, therefore, to disapprove the use of 
such vegetable remedies. A well-known medical man writes in 
Allbutt’s System of Medicine : — 
“ The chemical composition of a drug is not unfrequently 
the key to its pharmacological action If a drug have 
no active properties, it is surely devoid of medicinal effect unless 
it be a food ; for medicinal action is the outcome of the effects of 
active principles on tissues. It is always possible that in any 
particular drug the active medicinal agent may have escaped 
notice ; but in the present state of chemical science it is not 
likely that undiscovered principles reside in such substances 
as sarsaparilla and hemidesmus : yet these drugs are given on 
•Biochemistry of plants and animals has not yet been fully investigated. 
We do not know even much about the function of enzymes, regarding which 
two views are held one that they are a property and the other that they 
are a substance. Chemistry cannot produce them. They are found only as 
the products of protoplasm of living cells. It may be that many processes 
taking place in living cells are the results of Enzyme activity. 
