528 
Proceedings of the Eoyal Society 
Beyond these facts, I have found that the above named aqueous 
solution of salicylic acid also prevents the chemical action of 
hydration by means of the soluble zymases. If yeast is added to a 
solution of cane sugar, and to this solution the salicylic acid solution 
is added, no decomposition according to the following equation takes 
place : — 
^12^22^11 d* H 2 0 = C 6 H 12 0 6 + . 
That is, the salicylic acid has acted upon the soluble zymase 
which is secreted by the Torula cerevisive. Hence no fermentation 
takes place. I allowed the above to stand for two or three days at 
a temperature most suitable to engender alcoholic fermentation 
(about 80° F.), and then tested for glucose sugars by means of 
Fehling’s solution without any result. 
I also tried the action of salicylic acid solution upon a solution 
of starch which had previously been inoculated with a small 
quantity of saliva. After standing several days, I could not find 
the smallest trace of glucose sugar. 
From this, salicylic acid acts upon the soluble ferment (ptyalin) 
contained in saliva, preventing the hydrating action upon the 
amyloses. 
Then again, I have found that the above solution of salicylic 
acid acts chemically upon the cellulose walls of dead Torulae, 
destroying them in a similar manner to the organised ferments 
already described at the commencement of this paper, but it has 
no action on the living Torula. This shows that a chemical change 
must have taken place in the molecular structure of the cellulose 
■wall of the cell after the death of the organism. 
It is a well-known fact, that in every brewery the yeast becomes 
deteriorated at certain times, and hence the beer brewed by such 
yeast is not so good as formerly. This is due to “ diseased ferments ” 
in the yeast (viz., the organisms I have alluded to in the early 
part of this paper). The common remedy is for the brewer to 
change his yeast. But I have found that this is not essential, if 
the brewer waters the “ diseased yeast ” ( 1 i.e ., yeast containing these 
thread-like ferments) with a solution of salicylic acid, the 4 4 disease 
ferments ” are all destroyed, and the yeast is not acted upon by this 
solution. Yet at the same time the yeast so treated is not so active 
in its decomposition of a glucose solution into alcohol. This yeast 
