president’s address. 
291 
Honorary Secretary in succession to Mr. Nicholson. Dr. 
Long has already filled the office of President, and has shown 
his great interest in the Society in other ways. We are 
confident that the status of the Society will not suffer in 
his hands. 
One personal allusion I venture to make. On scanning 
the list of Past Presidents, I note that my father was 14th 
President of the Society in the 16th year of its existence — 
1884-5 — twenty-seven years ago. I have the honour to be 
41st President in the Society’s 43rd year. There are two 
other instances of father and son in the list, Messrs. Harmer 
and Messrs. Long, in both cases also the older generation 
being happily still with us. This is a pleasing feature of our 
Presidential roll, and, looking round on our vigorous member- 
ship, one hopes that other instances will occur. 
In passing to that portion of my address in which there 
is to be evolved from your President’s inner consciousness, or 
from his own or others’ experience, a topic “ conducive ” — 
in the words of Law X. of this Society — “ to the welfare of 
the Society, and the promotion of its objects,” I have rejected 
after some deliberation and preparation a subject of local 
bearing, in respect of which I have had the opportunity of 
gaining some small special knowledge. The time at my dis- 
posal to-night appeared too short to allow of its adequate 
treatment. I propose instead to refer to a few particular 
cases of chemical action in living matter, treating of 
'• Enzymes, with special reference to cyanogenesis.” 
By ‘enzymes” I mean the so-called “ unorganised ferments,” 
active substances which can be extracted from and can 
exercise their activity apart from the living tissue in which 
they are elaborated. By “ cyanogenesis ” I mean the pro- 
duction in plants of prussic or hydrocyanic acid by the action 
of enzymes on other bodies present in the plant cell. I have 
recently had occasion to study the phenomenon of cyano- 
