68 



Scientific Proceedings (89). 



at stated intervals. Counts were made on standard agar after 

 incubation for 24 hours at 37 0 C. 



The "pure water" used was twice redistilled in glass vessels 

 and again redistilled in a block tin condenser. It gave a negative 

 test for ammonia with Nessler's reagent. The sodium chloride 

 was purified by treatment with calcium hydroxide (to remove 

 magnesium), and with sodium carbonate (to remove calcium and 

 barium), and was then recrystallized from pure hydrochloric acid 

 and from pure water. The calcium chloride was twice recrystal- 

 lized and the crystals dried in a current of air and in the drying 

 oven. 



TABLE I. 

 Effect of Calcium Alone. 



Sol. 



Grams 

 CaCl2 in 

 iooC.c. 

 Water. 



Theoretical 

 Tonicity. 



Bacteria per C.c. Time after Seeding. 



1 Min. 



3 Hrs. 



6 Hrs. 



9 Hrs. 



04 Hrs. 



A . . 



0.000 





24,400,000 



36,700,000 



34,900,000 



34,200,000 



17,200,000 



B . . 



O.161 



O.I iso 



21,100,000 



13,100,000 



4,900,000 



4,800,000 



2,900,000 



C... 



0.805 



0-5 " 



27,900,000 



2,100,000 



230,000 



140,000 



44,000 



D . . 



1. 610 



1.0 " 



18,200,000 



2,800,000 



160,000 



53.000 



170 



E . . 



8.050 



S-o " 



11,400,000 



14,500 



0 



0 



0 



TABLE II. 

 Effect of Sodium Alone. 



Sol. 



Grams 

 NaCl in 

 100 C.c, 



Water. 



Theoretical 

 Tonicity. 



Bacteria per C.c. Time after Seeding. 



1 Min. 



2 Hrs. 



6 Hrs. 



25 Hrs. 



52 Hrs. 



A . . 







25,130,000 



25,030,000 



23,650,000 



23,500,000 



20,000,000 



B . . 



O.085 



O.I iso 



40,230,000 



39,250,000 



46,080,000 



42,500,000 



40,000,000 



C... 



O.425 



0-5 " 



40,650,000 



36,530,000 



48,600,000 



25,500,000 



25,100,000 



D . . 



O.850 



1.0 " 



34,350,000 



43,300,000 



41,430,000 



38,000,000 



16,850,000 



E . . 



4-250 



S-o " 



2,420,000 



163,000 



5.000 



900 



750 



F. . . 



8.500 



10. 0 " 



4,540,000 



42,500 



0 



0 



0 



TABLE III. 

 Effect of Calcium and Sodium Together 



Sol. 



In roo C.c. 

 Water, Grams. 



Theoretical 



Bacteria per C.c. Time after Seeding. 





NaCl. 



CaClj. 



Tonicity. 



1 Min. 



3 Hrs. 



6 Hrs. 



9 Hrs. 



24 Hn. 



A.. 



•35S 



•134 



0.5 iso 



1,940,000 



2,150,000 



2,800,000 



5,200,000 



7,600,000 



B. . 



.710 



.268 



1.0 " 



1,050,000 



3,850,000 



2,500,000 



4,900,000 



4,800,000 



C. . 



1.420 



•536 



2.0 " 



910,000 



3,200,000 



4,300,000 



4,400,000 



4,600,000 



D. . 



3-550 



I.340 



S-o " 



1,020,000 



1,275,000 



1,200,000 



2,200,000 



1,260,000 



E.. 



7.100 



2.680 



10. 0 " 



890,000 



98,000 



34.000 



45.000 



8,000 



Ratio of Na < — > Ca is the same in all solutions (5 < — > 1). 



