34 
EXPERIMENT NO. 11— Continued. 
EXPERIMENT NO. 12. 
Dilute formalin-permanganate method. 
Formalin, 600 c. c. 
Water, 300 c. c. 
Permanganate, 375 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, 0.0289 gram. 
(Determination made by draAving air from the room, beginning 14 minutes after mixing the 
formalin and permanganate, and consuming 45 minutes in the draAving.) 
Yield of formaldehyde, 27 per cent. 
Weather: Moderate east Avind, rainy. 
Tempera- 
ture. 
Relative 
humidity. 
Absolute 
humidity 
(grams per 
cubic foot) . 
Before mixing HCHO and KMnO< 
o j? 
81 
81 
82 
Per cent. 
77 
. 96 
88 
8.26 
10.82 
10.23 
After 10 minutes 
After 2 hours 
See note, Experiment No. 9. 
[4- means groAvth; — no groAvth.] 
Organism. 
Hoav exposed. 
Time of exposure in 
minutes, and re- 
sults. 
5 
10 
30 
60 
120 
B. pyocyaneus . . . 
Filter paper 
+ 
B. coli communis . . . 
do 
+ 
+ 
_ 
B . dyse.nte.rise 
do 
+ 
_ 
B. subtilis 
do 
+ 
+ 
+ 
_ 
B. coli communis... . . 
Wilson method 
+ 
+ 
_ 

R. snht.il.is 
do 
+ 
+ 
+ 
+ 
+ 
