544 



Drs. T. L. Brimton and A, Macladjen. 



These filtrates from the five series of cultures were sterilised as 

 described above. Then 5 — 10 c.c. of each were added to 10 per cent, 

 gelatine (20 c.c.) and kept at 37° C. y as well as control tubes of sterile 

 gelatine. 



On the third day the tubes were removed from the incubator and 

 placed in ice-cold water. 

 Results : — 



Scurf bacillus J The gelatine does not stiffen, but remains 

 Welford bacillus \ liquid. 



Koch's spirillum f The gelatine is semi-liquid, and does not 

 Finkler's spirillum [ completely re-gelatinise. 

 Putrefactive micrococcus 

 Control gelatine 

 Control plates. No bacteria. 



Kept at the ordinary room temperature, these phenomena persisted, 

 the liquid gelatine remaining liquid, and the solid gelatine not lique- 

 fying. 



Here, then, we have complete liquefaction of the gelatine produced 

 in the first two cases, partial liquefaction in the next two 7 and no 

 effect in the last. 



That this liquefaction was brought about without the presence of 

 active bacteria is proved by the fact that control plates inoculated 

 from the liquefied gelatine remained steirile. The complete lique- 

 faction was produced by the sterile fluid from the microbes which 

 were more active liquefiers of gelatine than the others. In the case 

 of the two comma spirilla the enzyme action in gelatine was 

 evidently more feeble. The negative result with the putrefactive 

 micrococcus, and also the fact that tubes inoculated from it, and kept 

 at the optimum temperature of 22° C, also gave negative results, 

 were probably due to the preliminary sterilisation having destroyed 

 both the microbes and any enzyme which they might have formed. 



These introductory experiments led to the following conclusions : — 



1. 100° C. destroyed both the bacteria and the liquefying power. 



2. 50° destroyed neither the bacteria ©or the liquefying power. 



3. Temperatures between 60° and 75° C. destroyed the bacteria, 

 but not the liquefying power in four cases. 



4. The liquefied gelatine treated as under 3, and added to fresh 

 gelatine, liquefied it y although active bacteria were proved to be 

 absent. 



5. The liquefaction must, we think, be due to a soluble enzyme, 

 inasmuch as liquefaction still took place after the elimination of the 

 microbes, while it was prevented by exposure to such a temperature 

 as would destroy the activity of an enzyme but would not be likely 

 to affect the action of a simple solvent. 



The gelatine stiffens. 



