260 



Mr. A. W. Blyth. 



[Nov. 26, 



reduce any antiseptic or inhibitory action of the minute quantity of 

 the chemical agent in the drop itself to a minimum, so as to exercise 

 no appreciable effect. 



The Thread Method. — In the thread method capillary glass rods 

 were made by drawing out ordinary glass tubing in the blow-pipe 

 flame, these were tipped with sealing-wax, and to the wax a little bit 

 of sterilised cotton wool was made to adhere. 



The end of the rod thus prepared was infected with the bacterium 

 by a short immersion in a pure cultivation and was then placed in the 

 disinfectant for twenty- four hours. The rod on removal was soaked 

 for a little time in sterilised water until all trace of the disinfectant 

 had been removed. 



The rod thus charged and purified was next inserted into a mass of 

 solid nutrient gelatin in a test-tube, and put on one side at the ordi- 

 nary temperature of the atmosphere, protected of course from external 

 contamination by a suitable plug of sterilised wool. Whether the 

 process used was that which I have called the " drop " or the 

 " thread," in each case " control " experiments were made with threads 

 infected with the bacterium, but which had not been submitted to 

 disinfection. 



Alcohol, Ether, 8fc. — As it was necessary to dissolve many of the 

 substances experimented upon in weak alcohol, a series of experiments 

 were made to ascertain the influence of alcoholic and other solvents 

 on the life of the bacterium, and the following table gives the result. 

 Alcohol of 60 per cent, disinfected, but absolute amyl alcohol, pure 

 ether, chloroform, and carbon disulphide merely delayed the growth. 



Alcohol, Chloroform, Ether, and Carbon Disulphide — (Thread 



Method). 



Days 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 



10. 



11. 



12. 



At 15-5°— 

























Alcohol 5 per cent. . . 



+ 























„ 10 



+ 























„ 20 „ 





+ 





















„ 30 





+ 





















„ 40 







+ 



















„ 60 „ 



+ 























„ 80 

























Carbon disulphide .... 

















+ 









„ water 





+ 





















5 : 5. 

























Carbon disvdphide water 





+ 





















(saturated) 

































+ 











































+ 























