58 
the room and it was impossible to determine the time at which the 
process of evolving the gas was completed. The room was not closed 
until it was found that the formaldehyde gas was being given off by 
the lamp. This was detected by its irritating action on the mucous 
membrane of the eyes and nose. However, in two experiments the 
exposures were made 2 hours after starting the lamp and closing the 
room. 
A summary of conditions and results is given in each of the following 
experiments : 
EXPERIMENT NO. 32. 
Generating lamp. 
Methyl alcohol, 1,000 c. c .a 
Capacity of room, 2,000 cubic feet. 
Weather: No wind, slightly cloudy. 
Tempera- 
ture. 
Relative 
humidity. 
Absolute 
humidity 
(grams per 
cubic foot). 
Before starting lamp 
0 F. 
73 
Per cent. 
82 
7. 20 
After 1 horn” 
81 
85 
9.58 
After 2 hours 
81 
98 
11.05 
After 3 hours 
79 
98 
11.05 
Time of exposure of organisms counted from time of starting the lamp. 
[+ means growth; — , no growth.] 
Organism. 
B. coli communis . 
B. subtilis 
B. pyocyaneus 
B. typhosus 
B. coli communis. 
B. subtilis 
B. coli communis . 
How exposed. 
Glass 
do 
Filter paper 
do 
do 
do 
Wilson method 
Time of exposure in minutes 
and results. 
10 
20 
30 
45 
60 
120 
180 
+ 
+ 
+ 




+ 
+ 
+ 
+ 
+ 
- 
- 
+ 
+ 
+ 
- 
- 
- 
- 
+ 
+ 
+ 
- 
- 
- 
- 
+ 
+ 
+ 
- 
- 
- 
- 
+ 
+ 
+ 
+ 
+ 
- 
- 
+ 
+ 
+ 
+ 
+ 
— 
— 
a For a room of this size the United States Quarantine regulations require 1,400 c. c. of methyl 
alcohol. 
