132 



Scientific Proceedings (92). 



then returned to the incubator and kept there throughout the 

 remainder of the experiment. The number of organisms surviving 

 was determined at stated intervals. The counts were made on 

 standard agar after 24 hours incubation at 37 0 C. 



All the reagents used in these experiments were of the same 

 high purity as those which were employed in the experiments re- 

 ported in our earlier communication. All the glassware had been 

 very carefully cleaned with chromic acid oxidizing mixture, rinsed 

 in tap water and in distilled water. 



Table I shows the result of transfer from 0.1 isotonic NaCl 

 solution to 0.001 isotonic NaCl (1 c.c. of the first solution containing 

 the bacteria to 99 c.c. of sterile distilled water), from 0.1 isotonic 

 NaCl to another bottle of the same solution, and from 0.1 isotonic 

 CaCl 2 to another bottle of the same solution. Three independent 

 experiments are cited in each group. In each of these three series 

 of experiments the reduction in bacterial numbers was relatively 

 small in 9 hours although in the case of the CaCl 2 the normal 

 toxicity of this salt manifested itself to a slight degree. In each 

 case, of course, there is a decrease in actual count in the transfer 

 to about 1 per cent, of the original number present, but this is the 

 result of the dilution and does not imply the death of the bacteria- 



The transfer from 0.1 isotonic CaCl 2 to 0.001 isotonic CaCl 2 

 as shown in Table II is accompanied on the other hand by a rapid 

 destruction of bacteria so that after 8-9 hours only a few hundred 

 bacteria are left out of hundreds of thousands. 



TABLE I. 



Viability of B. communis Transferred from a Strong to a Weak Sodium Solu- 

 tion and from Sodium and Calcium Solutions to Solutions of the 

 Same Strength. 







Time after Seeding. 



Time after Transfer. 



1 Min. 



30 Min. 



120 Min. j 240 Min. 



360 Min. 



540 Min. 



0.1 isotonic 



Bacteria 



29,600,000 



29,700,000 



280,000 270,000 



260,000 



270,000 



NaCl to 0.001 



per 



35,500,000 



32,500,000 



285,000 240,000 



235,000 



210,000 



isotonic NaCl 



c.c. 



33,500,000 



30,000,000 



215,000 195,000 



195,000 



180,000 



0.1 isotonic 



Bacteria 



35,500,000 



32,500,000 



370,000 312,000 



310,000 



240,000 



NaCl to 0.1 



per 



33,500,000 



30,000,000 



260,000 245,000 



255,000 



210,000 



isotonic NaCl 



c.c. 



33,500,000 



30,000,000 



255,000 230,000 



260,000 



230,000 



0.1 isotonic 



Bacteria 



26,500,000 



26,500,000 



300,000 300,000 



240,000 



170,000 



CaCh to 0.1 



per 



29,200,000 



28,300,000 



200,000 170,000 



70,000 



40,000 



isotonic CaCh 



c.c. 



33,500,000 



26,500,000 



295,000 255,000 



210,000 



170,000 



