21 
Inoculations into bouilloD at definite intervals were made and placed 
in the incubator at 37° C. Following are the results with the differ- 
ent organisms used: 
Besults y:hen B. dysenterise {Shiga) was exposed in percentages of zinc chloride prepared 
in sterile seicage. 
[-i- means growth; — means no growth.] 
Percentage ZnCL 
Time of exposure in hours. 
1. 
2. 
3. 
5. 
7. 
24. 
1 
_ 
+ 
+ 
+ 
2 
”T 
-F 
4- 
+ 
— 
5 
~r 
“T 
+ 
“h 
Results when B. typhosus was exposed in percentages of zinc chloride prepared in sterile 
seicage. 
Exposure in hours. 
• K. 
.1. 2. 
3. 
5. 
1 + 
+ + 
"r 
2 ^ 
+ 
— 
— 
5 -f 
Results when Vibrio cholerse icas exposed in percentages of zinc chloride prepared in sterile 
sewage. 
Percentage ZnCI- 2 . 
Exposure in hours. 
1. 
2. 
3. 
5. 
1 
_L 
+ 
2 
-L 
5 
_1 
— 
Results when B. pyocyaneus was exposed in percentages of zinc chloride prepared in 
sterile sewage. 
Percentage ZnClo. 
1 Exposure in hours. 
1 
1. 
2. 
3. 
5. 
72. 
1 
+ 
+ 
■ 7'i 
_U 
_U 
2 
+ 
+ 
-t- 
4- 
5 
+ 
4 - 
"i" 
Controls were all viable at the end of 3 days. 
Sterilization of sewage of course alters its natural composition to a 
certain extent, but it is the only practical way in which the viability 
of the pathogenic organisms used in these experiments with zinc 
chloride in sewage can be determined with any degree of accuracy. 
A comparison of the results obtained under these conditions show 
that the}^ do not differ materially from those obtained under similar 
conditions when distilled water is used instead of sterile sewage. 
