New YorK AGRICULTURAL EXPERIMENT STATION. 173 
EFFECT OF PLANT JUICES. 
Inasmuch as in the cases of actual decay of vegetables the 
enzym must occur in solution in the cell sap, it is of interest 
to learn whether the normally acid sap tends to retard its ac- 
tion as do the organic acids mentioned above. Two series of 
trials were made to determine this. In the first the juice was 
expressed from living tissues of each, carrot, radish and ripe 
tomato. These were tested by adding to each, respectively, 
equal parts of a 5% aqueous solution of the precipitated enzym 
from a carrot broth culture. The result was, therefore, a 2.5% 
solution of the precipitate in half-strength vegetable juice. 
There was slight retardation in all cases in the rate of action 
as compared with solutions in distilled water, this being a lit- 
tle more pronounced in the case of the tomato. The test was 
repeated with the tomato juice by dissolving 5% of the pre- 
cipitate directly in the juice, thus placing the enzym in the 
presence of the full degree of acidity. Here the retardation 
was considerable, estimated at nearly one-half, i. e., there was 
about as much action in fifteen minutes in a water solution 
as in one-half hour in the tomato juice solution. 
Titration of these vegetable juices showed the acidity of the 
tomato to be +5%, of the carrot +2%, of the radish -L0.75%. 
THE EFFECT OF OTHER BACTERIAL PRODUCTS. 
As a result of his studies on the bacterial soft rot of the 
turnip due to Pseudomonas destructans, Potter (1900: 451) 
suggested that oxalic acid produced by that organism may play 
some part in the destruction of the middle lamella and the 
separation of the cells. The above results show that neither 
oxalic acid nor any of the normal acids of the host tissues so 
function in the carrot rot organism. Indeed this organism 
produces no oxalic acid. It does, however, produce a small 
amount of some undetermined acid in the presence of carbo- 
hydrates. In order fully to determine whether this unknown 
‘organic acid or other products of the bacterial metabolism 
favor or retard the enzym action, broths of various kinds in 
which the organism has been grown were heated to 80° C. to 
