35 
EXPERIMENT NO. 13. 
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, 0.03755 gram. 
(Determination made by drawing air from the room, beginning 15 minutes after mixing the 
formalin and permanganate, and consuming 34 minutes in the drawing.) 
Yield of formaldehyde, 35.1 per cent. 
Weather: Moderate breeze from west, few clouds. 
Tempera- 
ture. 
Relative 
humidity. 
Absolute 
humidity 
(grams per 
cubic foot) . 
Before mixing HCHO and KMnOi 
°F. 
85 
85 
85 
Per cent. 
70 
90 
82 
8. 91 
31.21 
10.43 
After 10 minutes 
After 2 hours 
See note, Experiment No. 9. 
[+ means growth; — no growth.] 
EXPERIMENT NO. 14. 
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, 0.0341 gram. 
(Determination made by drawing air from the room, beginning 17 minutes after mixing the 
formalin and permanganate, and consuming 42 minutes in the drawing.) 
Yield of formaldehyde, 31.84 per cent. 
Weather: Very light breeze, clear. 
Tempera- 
ture. 
Relative 
humidity. 
Absolute 
humidity 
(grams per 
cubic foot) . 
Before mixing HCHO and KMnOi 
°F. 
85 
85 
86 
Per cent. 
70 
88 
83 
8.91 
11. 21 
10. 89 
After 10 minutes 
After 2 hours 
See note, Experiment No. 9. 
