fond 
New York AGRICULTURAL EXPERIMENT STATION. phyia? 
with several other enzyms. This suggests that, in general, an 
enzym may enter into such a relation, either with the sub- 
stance upon which it acts or with some other compound asso- 
ciated with it in solution, that as a result it may receive some 
protection against the injurious action of heat or other dele- 
terious agencies. It is, of course, possible that the enzym in 
the original broth is in such relation to some organic matter 
as to be thus protected, but our attempts to protect it by the 
presence of carrot tissues in these experiments were ursuc- 
cessful since, as stated above, it was destroyed at the same 
temperature whether in the presence or the absence of the car- 
rot sections. It is to be noted, however, that we were work- 
ing here with the alcoholic precipitate redissolved in water. 
Woods (1899) has shown that the oxydizing enzyms of the 
maple leaf withstand higher temperature when in the juices 
of the plant than when in the presence of alcohol. 
In comparison with our results it is interesting to note that 
Brown and Morris (1890) found 35°-40° C. an _ especially 
favorable temperature for the cytolytic enzym of germinating 
barley, whereas it became decidedly less energetic at 50° and 
was almost completely paralyzed at 60°. 
EFFECT OF ACIDS AND ALKALIiES. 
The organism as studied was found to be parasitic on various 
vegetables, all of which possess an acid cell sap. In the course 
of its development, however, it renders the sap alkaline. It 
appears of interest, therefore, in connection with the question 
of the parasitism of the organism to learn the relation of the 
‘reaction of the medium to the activity of the enzym. This 
was investigated, using the alcoholic precipitate obtained from 
carrot broth cultures. Solutions of this were made in dis- 
tilled water containing additions of the chemicals under trial 
and their activity tested on razor sections of carrot. The 
strength of the acid and alkali solutions was in all cases de- 
termined by titration-against phenolphthalein. 
Alkali.— It was found that the presence of sodium hydrox- 
ide titrating — 2% inhibited the reaction slightly, and that the 
