L70 REporRT OF DEPARTMENT OF BACTERIOLOGY OF THE 
there is no loss where the dried enzym-containing precipitate is 
kept for months or even years. Thus two samples of precipi- 
tates prepared and carefully tested in May, 1901, were kept 
and again tested in May, 1903, when so far as we could 
judge their activity was as great as when prepared two years 
before. 
Spieckermann (1902: 166) states that the activity of the 
similarly dried enzym precipate obtained from his kale-rot 
organism was undiminished after four months in the dry state. 
RELATION OF TEMPERATURE TO ACTIVITY. 
Temperature relations were studied, using solutions of the 
alcoholic precipitate from carrot broth cultures and testing 
them on carrot sections. It was found that the action was 
slight at 2° C., good at 22°, better at 32°, best at about 42°, 
inhibited somewhat at 48°, showed pronounced inhibition at 
50° and was practically or entirely checked at 51° and abeve. 
For example, the action was nearly twice as rapid at 42° as at 
22°; and at 32° it was practically midway in rate between the 
higher and the lower. The optimum lay between 40° and 45°. 
When such solutions were held at various temperatures up to 
49° for an hour, either in the presence or the absence of carrot 
tissues the enzym was uninjured, i. e., they showed normal. 
activity when the temperature was lowered again. If, how- 
ever, the heating was carried to 51° or above for ten minutes, 
whether in the presence or absence of carrot tissue, little if 
any action ensued thereafter. 
A comparison of these results using the precipitated enzym 
with those described earlier in this article where the original 
broth was used, shows that the points of inhibition and de- 
struction were approximately ten degrees lower in the solu- 
tions of the precipitate. 
It is interesting in this connection to recall (cf. Green 
1901: 448) that observations upon invertase have shown that 
it withstands a temperature higher by 25° C., when cane sugar, 
upon which it acts, is present than it does in its absence. A 
similar variation, though not so extreme, has been observed 
