DECOMPOSITION OF EXTRACTS 299 



been examined on several occasions, and owing to the 

 infection of its contents the latter was in a foul-smelling 

 condition. The increased augmentation when this 

 decomposed extract was used was so remarkable that 

 we decided to try its action by itself without any azur 

 or other stain. 



The jelly was made up thus: To 5 cc. of coefficient 

 jelly 3 cc. of the putrid extract, and 0.8 cc. of 

 5-per-cent solution of sodium bicarbonate (8 units of 

 alkali) were added. The alkali was present in order 

 to cause the contents of the jelly to diffuse into the 

 cells. The jelly w T as made up to a total of 10 cc. with 

 1 . 2 cc. of water. In order to prevent coagulation of the 

 extract a film was prepared from the jelly in the 

 following way: The coefficient jelly was melted and 

 boiled, and it was only as it cooled that the extract 

 was added, the film being made immediately before 

 the jelly had set in the test-tube. Fresh blood from 

 the finger was spread on the jelly in the usual manner 

 under a cover-glass. After incubation for ten minutes, 

 an examination showed that some of the lymphocytes 

 appeared to be in an early stage of mitosis. Now, 

 we could not be very certain about this point, because 

 no stain was present and consequently the chromo- 

 somes were unstained and almost invisible. If mitotic 

 divisions are sometimes difficult to see in stained 

 specimens, they are much more difficult to distinguish 

 when no stain is employed. Still, the cells looked 

 rather as if they were attempting to divide (fig. 96). 



A fresh jelly was made, but it contained 1 cc. of 

 alkali solution instead of 0.8 cc. ; and now there was 



