Annual Address by the President. 
17 
of the reaction — the positive eataylzers accelerating, and the nega- 
tive catalyzers retarding the velocity of the reactions. Catalyzers, 
then, serve in the capacity of liberating impulses. 
That zymohydrolysis is. a chemical action finds further support 
in the recent work of A. Croft Hill 20 on “Reversible Zymohydroly- 
sis.” By varying the concentration of mixtures of glucose and 
maltose he found that the equilibrium point of these two sugars 
was reached when 85.5% of glucose and 14.5% of maltose were 
present. Increasing the glucose beyond 85.5% sent the hydrolysis 
one way, and the reaction reversed when the maltose was increased 
beyond 14.5%. This is in strict conformity with the law that 
Cf every reaction proceeds to a state of equilibrium , with a definite 
reaction velocity 
The phenomena of reversible reactions have been well worked out, 
and KonowalowV 1 reaction of acetic acid upon pentene : 
CHjCO.OH + C S H 10 0 H s CG.0(0 5 Hj j), 
has been shown to conform to the requirements of the law of mass- 
action by Fernst and Hohmann. 22 
Another very important observation made by Bredig and von 
Berneck 23 is that “relatively minute portions of certain substances 
are able to inhibit the catalytic action of platinum, and that these 
are substances which exert a markedly poisonous effect on the living 
cell and on enzymes. 1/345,000 gram-molecule per litre of hydro- 
gen sulphide already exerts a strongly restraining action. 1/1000 
gram-molecule per litre of hydrocyanic acid stops it -entirely, and 
much less is able to retard it greatly. Carbon disulphide, and 
mercuric chloride show a similar behavior.” This again parallels 
the action of ferments and antiferments. 
Were it necessary, many other interesting parallels could be 
drawn to show the intimate connection between the phenomena of 
fermentation and the phenomena of chemical action ; but this must 
suffice to authorize the statement that the complex phenomena of 
fermentation can be best understood when viewed from the pinacle 
of modern chemical theory: — the Avogadro-vanT Hoff Rule, the 
Phase Rule, Electrolytic Dissociation, and the Doctrine of Energy. 
Having shown that chemistry helps us to understand fermenta- 
tion, let us see what light it is capable of sheding upon 
INFECTION. 
The fact that the poisonous action of the bacteria is due to the 
soluble products formed by the bacteria was established by Panum 
in 1874. Later, Koch, Chauvean and others succeeded in separat- 
