64 
EXPERIMENT NO. 38— Continued. 
[4- means growth; — no growth.] 
Organism. 
How exposed. 
Time of exposure in min- 
utes, and results. 
1 
10 
20 
30 
45 
60 
B. coli communis 
Glass. 
+ 
B. subtilis 
do 
B. pyocyaneus 
Filter paper 
+ 
4- 
B . typhosus 
do 
-f 
-J- 
B. coli communis 
do 
4- 
+ 
4- 
B. subtilis 
do 
4- 
4- 
B. coli communis 
Wilson method 
4- 
4- 
EXPERIMENT NO. 39. 
Formalin-aluminum suljphate-lime method. 
Formalin, 600 c. c. 
Solution of aluminum sulphate in water (proportion of 50 grams to 100 c. c. of water), 300 c. c. 
Water, 300 c. c. 
Unslaked lime, 2,500 grams. 
Capacity of room, 2,000 cubic foot. 
Quantity of formaldehyde used per cubic foot, 0.107 gram. 
Percentage yield of formaldehyde undetermined. 
Weather: Light westerly wind, cloudy. 
Tempera- 
ture. 
Relative 
humidity. 
Absolute 
humidity 
(grams per 
cubic foot) . 
Before mixing formalin, aluminum sulphate, and lime 
0 F. 
71 
Per cent. 
58 
4.78 
After 10 minutes 
72 
82 
6.98 
After 20 minutes 
72 
86 
7.31 
After 3 hours 
74 
65 
5.89 
Time of exposure of organism counted from time of mixing the formalin-aluminum solution and lime. 
[4- means growth; — no growth.] 
Organism, 
B. pyocyaneus . . . 
B. coli communis 
B. subtilis 
B. typhosus 
B. coli communis 
B. subtilis 
How exposed. 
Time of exposure in minutes, and 
results. 
10 
20 
30 
45 
60 
90 
120 
180 
Glass 
4* 
4- 
4- 
do 
.4- 
4- 
4- 
4- 
+ 
+ 
- 
— 
Filter paper 
4- 
do 
4- 
4- 
- 
- 
- 
- 
- 
- 
do 
+ 
4- 
4- 
4- 
4" 
4- 
4- 
4- 
