24 
EXPERIMENT NO. 1 — Continued. 
[+ means growth; — no growth.] 
Organism. 
How exposed. 
5 
15 
30 
45 
60 
120 
B. pyocyaneus 
Filter paper 
B. coli communis 
do 
B. dysenteric 
do 
+ 
B. subtilis 
do 
+ 
+ 
B. coli communis 
Wilson method 
+ 
+ 
+ 
+ 
B. subtilis 
do 
+ 
+ 
+ 
+ 
+ 
Time of exposure in min- 
utes, and results. 
EXPERIMENT NO. 2. 
Formalin-permanganate method. 
Formalin, 600 c. c. 
Permanganate, 300 grams. 
Capacity of room, 2,000 cubic feet. 
Quantity of formaldehyde used per cubic foot, 0.107 gram. 
Quantity of formaldehyde found per cubic foot, 0.0419 gram. 
(Determination made by drawing air from the room, beginning 17 minutes after mixing the 
formalin and permanganate, and consuming 1 hour 21 minutes in the drawing.) 
Yield of formaldehyde, 39.15 per cent. 
Weather: Practically no wind. 
Tempera- 
ture. 
Relative 
humidity. 
Absolute 
humidity 
(grams per 
cubic foot). 
Before mixing HCHO and KMnCb 
° F. 
79 
Per cent. 
79 
8.39 
After 10 minutes 
79.5 
94 
10.10 
After 1 hour 
79.5 
89 
9.57 
See Note, Experiment No. 1. 
[+ means growth; — no growth.] 
Organism. 
How exposed. 
Time of exposure in minutes, 
and results. 
5 
10 
15 
20 
30 
45 
60 
B. pyocyaneus 
Filter paper 
B. coli communis 
do 
B. dysenteric 
do 
+ 
B. subtilis 
do 
+ 
-I- 
+ 
+ 


B. coli communis 
Wilson method 
+ 



B. subtilis 
do 
+ 
+ 
+ 
+ 
+ 
+ 
_ 
