EFFECT OF COPPER UPOl^ WATER BACTERIA. 



65 



Table XXI. — Effect of carbon dioxid upon toxicity of copper sulfate to Bacillus coli.'^ 





Check. 



1 part copper sulfate to — 



Duration of exposure to action of copper 

 sulfate. 



] 0,000 

 parts of 

 water. 



50,000 

 parts of 

 water. 



100,000 

 parts of 

 water. 



500,000 

 parts of 

 Abater. 



1,000,000 

 parts of 

 water. 



hour 



Colonies. 

 9,200 

 2,000 



Colonies. 



8,200 







Colonies. 



5,800 



110 



Colonies. 



11, 600 



38 



Colonies. 



7, 500 



900 



Colonies. 



6,200 



350 



2 liours .... 







1 Experiment conducted in Weber resistance glass test tubes, each containing 10 c. c. of water triple 

 distilled from glass, portions of which had been treated previously with the desired amount of copper 

 sulfate. All tubes inoculated with a 2 mm. loop of culture of Bacillus eoli received from Prof. Theo- 

 bald Smith. The temperature during this experiment varied from 18° to 22° C. 



Table XXII. — Effect of water containing calcium monocarbonate and various quantities 

 of copper sulfate upon Bacillus coli.^ 





Check. 



1 part copper sulfate to— 



Duration of exposure to action of copper 

 sulfate. 



10,000 

 parts of 

 water. 



50,000 



parts of 



water. 



100,000 



parts of 



water. 



500,000 

 parts of 

 water. 



1,000,000 

 parts of 

 water. 





Colonies. 



2,950 



240 



5 



Colonies. 



3,510 











Colonies. 



2,670 



. 







Colonies. 



3,150 











Colonies. 



4,290 



105 







Colonies. 

 3 760 



6 hours 



24 hours 



80 

 







1 Various dilutions of copper sulfate were tubed in Weber resistance glass, thoroughly boiled, a small 

 measured quantity of calcium carbonate added to each tube, and these solutions cooled and kept in 

 a Novy jar in an atmosphere free of carbon dioxid. All tubes inoculated with a 2 mm. loop of cul- 

 ture of Bacillus coli received from the Bureau of Animal Industry and isolated from hog. The tem- 

 perature during this experiment varied from 18° to 22° C. 



Table XXIII. — Effect of carbon dioxid content of water containing calcium carbonate 

 and various quantities of copper sulfate upon Bacillus coli. -^ 



Duration of exposure to action of copper 

 sulfate. 



Check. 



1 part copper sulfate to — 



10, 000 

 parts of 

 water. 



50,000 

 parts of 

 water. 



100,000 

 parts of 

 water. 



500,000 1,000,000 

 parts of parts of 

 water. water. 



hour . 

 6 hours. 

 24 hours 



Colonies. 

 4,650 

 4,500 

 5,200 



Colonies. 



4,730 











Colonies. 



3,850 











Colonies. 



3,980 



5 







Colonies. Colonies. 



4, 100 4, 470 



415 620 



15 60 



1 Various dilutions of copper sulfate were tubed in Weber resistance glass, thoroughly boiled, a 

 small measured quantity of calcium carbonate added to each tube, and these solutions cooled and 

 kept in a Novy jar in an atmosphere composed largely of carbon dioxid. All tubes inoculated with 

 a 2 mm. loop of culture of Bacillus coli received from the Bureau of Animal Industry and isolated 

 from hog. The temperature during this experiment varied from 18° to 22° C. 



Table XXIV. — Toxicity of copper sidfate to Bacillus coliin tap ivater free of carbon dioxid.'^ 





Check. 



1 part copper sulfate to— 



Duration of exposure to action of copper 

 sulfate. 



10.000 

 parts of 

 water. 



50,000 

 parts of 

 water. 



100,000 

 parts of 

 water. 



500,000 

 parts of 

 water. 



1,000,000 

 parts of 

 water. 





Colonies. 



6,300 



1,500 



280 







Colonies. 



7, 600 















Colonies. 



6,000 















Colonies. 



1,050 















Colonies. 



4,800 



Lost. 











Colonies. 

 5,200 



2 hours . 



60 



6 hours 

















1 Experiment conducted in Weber resistance glass test tubes, each containing 10 c. c. of Potomac tap 

 water, portions of which had been treated previously with the desired amount of copper sulfate. 

 All tubes inoculated with a 2 mm. loop of culture of Bacillus coli received from the Bureau of Animal 

 Industry, isolated from hog. The temperature during this experiment varied from 18° to 22° C. 



18270-^No. 100—07 5 



