58 



KRAEMER— ACTION OF COPPER FOIL 



[April 



C. to 37° C. To six of the flasks were then added strips of copper 

 foil about 15 mm. wide and 18 cm. long, these being corrugated 

 in such a manner that the entire surface was exposed to the water. 

 Plates were made from all the 12 flasks at the end of 4 hours and 

 8 hours, and 1 day, 2 days, and 6 days, even in the cases where no 

 organisms remained, and in the cases in which they continued to 

 develop, also at the end of 14, 21, 28, 53, 60, 83, 90, 120, 130 

 and 134 days. The results are given in the accompanying tables. 



Table II. — Experiments with Bacillus typhosus. 1 



Water Without Copper Foil. 



Triple Filtered 

 Distilled Tap 

 Water. Water. 



Tap 

 Water. 



Water With Copper Coil. 



Dis'tilled Filtered Tap 



Water. Water. Water. 



At time 

 At end 



of adding culture, 

 of 4 hours. 



24 " 

 4 S « 

 6 days 

 14 " 

 21 " 

 28 " 

 602 

 90 



days 



134 



3.740 

 2,835 



3,85o 



3,75o 



3,8i5 



1,850 



16,380 



39,690 



153,600 



295,866 



239,400 



78,75o 



34,440 



4,75o 

 No or- 

 ganisms. 



3,675 

 3,8i5 



1,995 

 i,435 



i,540 



3,986 127 



No or- No or 

 ganisms. ganisms. ganism 



1,400 

 No or- 



3,920 



65,500 



221,867 



961,800 



346,500 



9,156 



7,875 



1 Bouillon cultures of the different samples of water, at the end of 60 days, 

 gave with Widal's test the characteristic behavior of typhoid organisms. After 

 60 days the organisms were found to be very long and more or less filamentous 

 and did not respond to Widal's test. I am indebted to Dr. Herman B. Allvn, 

 Philadelphia, for specimens of typhoid blood. 



It is seen in the foregoing tables that in all the flasks to which 

 copper foil had been added all of the organisms were destroyed in 

 less than four hours, and furthermore the solutions remained 

 sterile as shown by plates made for a number days thereafter. 



I may say that every single experiment which we have conducted, 

 not only those given in the foregoing tables, but all others, shows 

 that copper foil is exceedingly toxic to colon and typhoid bacilli, 

 particularly the latter. 



It will be seen further that in the filtered water, to which no 

 copper foil had been added, the typhoid organisms did not develop 

 as was the case with the tap water and distilled water, although 



