15 
j a- the condition of this supernatant liquid and residue as regards sterility. 
'' I In order to ascertain this, inoculations were made from the super- 
. j, natant portion af each flask by transferring with a sterile pipette 1 or 
' 5 drops of it to nutrient bouillon and placing it in the incubator at 
37° C. Considering the absence of growth under these conditions as 
J evidence of sterility, the following tables will show the results obtained 
I with the supernatant portion of the ditferent series of flasks containing 
A^arious percentages of zinc chloride: 
« Table A . — Germicidal influence upon the supernatant liquid when zinc chloride is added 
to ordinary sewage and kept at room temperature. 
[— means growth; — means no growth.] 
Percentage ZnClo. 
Time of exposure in days. 
6. 
7. 
9. 
10. 12. 
14. i 
1:500 
+ 
+ 
T- — 
+ 
1:200 
J_ 
+ 
+ 
~ “T 
-U 
1:100 
+ 
+ 
+ 
_ "T 
— 
1:75 
-j- 
_L_ 
_1_ 
— 
1:50 
-r 
-U 
P 
— 

1:45 
-r 
g- 
1:40 
-U 
1 
Table B . — Germicidal influence upon the supernatant liquid when zinc chloride is added 
to equal volumes of ordinary sewage and tap water and kept at room temperature. 
Percentage ZnCP. 
Time of exposure in days. 
6. 
7. ■ 9. 
10. 
12. 
14. 
1:500 
+ + 
+ 
+ 
1:200 
4“ 
-r -f 
— 
+ 
+ 
1.100 
+ 
+ -f 
-i- 
+ 
— 
1 : 75 
+ 
+ + 
+ 
— 
— 
1:50 
j_ 
+ 4- 
— 
— 
— 
1:45 
+ 
4~ 
— 
— 
— 
1:40 
+ 
— — 
— 
— 
— 
Table C.^ — Germicidal influence upon the supernatant liquid ichen zinc chloride is added 
to ordinary sewage and bouillon and kept cd room temperature. 
From the aboA^e results it aauU be observed, as might be expected, 
that the microorganisms remained Auable longer in the flasks contain- 
ing the most nutrition, other things being equal. The supernatant 
portions of the two series of flasks containing no nutrient bouillon 
were sterile at the end of 11 days in a proportion of zinc chloride of 
