174 Report OF DEPARTMENT OF BACTERIOLOGY OF THE 
sterilize them and to destroy their enzym content. Two parts . 
of each of these, respectively, was then added to one part of a 
~ solution in water of the enzym-containing precipitate and the 
activity of this mixture was tested in comparison with a solu- 
tion of like strength of the precipitate in pure water. More 
or less inhibition resulted in every case, as follows: Carrot 
broth, cultures twelve days old, reaction to litmus slightly 
alkaline, slight inhibition; beef broth, cultures seven days old, 
reaction to litmus slightly alkaline, marked inhibition; Dun- 
ham’s peptone solution, cultures sixteen days old, reaction 
to litmus neutral, decided inhibition, estimated to be one-half 
as active as the solution in pure water; Dunham’s peptone 
solution plus 2% sugar, cultures sixteen days old, reaction to 
litmus strongly acid, decided inhibition, so that the tissues 
tested in this solution were not more acted upon at the end 
of twenty hours than were those in the simple Dunham/’s solu- 
tion at the end of two hours. There is no evidence here, there- 
fore, that the products of the bacterial growth aid in the 
cytolytic action of this organism. On the contrary, the evi- 
dence is that they tend to inhibit it. 
DIASTATIC ACTION. 
Repeated trials by the most delicate methods we could devise 
have failed to reveal any diastatic action worthy of note. The 
only indication observed has been an extremely slow and 
slight tendency to the conversion of starch into amylodextrin, 
as shown by a gradual change in iodine reaction from a clear 
blue to slightly purplish tint. Starch granules are not eroded 
even in cultures on potatoes, nor is there any change in the 
iodine reaction of such raw potato tissues, nor of cooked po- 
tatoes when used as a culture medium, except the slight one 
toward the purplish tint just noted. More delicate tests were 
made by mixing 1% of the washed starch from potato or wheat 
flour with water, heating to the boiling point, allowing to 
settle nearly clear and then filtering off the supernatant 
liquid. In this way a very weak starch solution was secured, 
but one which gives a clear iodine reaction. Saliva added to 
