31 
The results are shown in the following table: 
Table 2.— Experiments with the diluted formalin-permanganate method. 
© 
£ 
5 . © 
O 
P r © 
^ ~ 3© c 
2 © £ o 
3 oj > s 
5a © ' n 
© 1_ C3 
— c g c 
g n © 
© pC c w 
Water. 
q 
w 
Time between mixing 
and drawing air. 
© u 
© 
Volume of air drawn, 
in liters. 
Relative humidity 
before experiment. 
Relative humidity 10 
minutes after mixing. 
Increase in grams of 
moisture per cubic 
foot. 
Abs. formaldehyde 
used per cubic foot. 
Abs. formaldehyde 
found per cubic foot. 
Per cent yield. 
Condition o 
wind, etc. 
°F. c. c. 
c. c. 
gm. 
h. m. 
h. m. 
g. m. 
g. m. 
I 
SI 600 
600 
450 
17 0 
al 20 
10 
81 
94 
1.79 
0.107 
0.0272 
25.4 
Slight breeze. 
& 1 20 
10 
.107 
.0272 
25.4 
Do. 
II 
81 600 
300 
450 
16 0 
1 5 
10 
83 
98 
2.06 
.107 
. 030S1 
28.8 
Moderate wind. 
III 
81. 5 1 600 
300 
300 
16 0 
a 1 9 
5 
74 
94 
2.28 
.107 
.0242 
22.6 
Do. 
b 1 8 
10 
.107 
.02336 
21.8 
Do. 
IV 
81 600 
300. 
375 
14 0 
aO 45 
5 
77 
96 
2.14 
.107 
.0289 
27 
Brisk wind. 
b 1 14 
10 
.107 
.02965 
27.7 
Do. 
V 
85 600 
300 
375 
15 0 
aO 34 
- 
0 
70 
90 
2.55 
.107 
. 03755 
35.1 
Gentle breeze. 
b 1 5 
10 
.107 
.0356 
33.27 
Do. 
VI 
85 600 
300 
375 
a 0 17 
0 42 
5 
70 
88 
2.3 
.107 
.0341 
31.84 
Do. 
b 0 17 
1 20 
10 
.107 
.03296 
30.80 
Do. 
c 2 27 
1 18 
10 
.107 
.02548 
23.81 
Do. 
d 4 24 
1 0 
10 
.107 
.02276 
21.27 
Do. 
e 24 33 
1 23 
10 
.107 
.01028 
9.6 
Do. 
VII 
79 600 
300 
375 
a 0 21 
b 0 21 
0 47 
1 17 
5 
10 
79 
94 
1.72 
.107 
.107 
.03517 
.03517 
32.87 
32.87 
Practically no 
wind; win- 
dows and 
doors pasted 
c 4 7 
1 18 
10 
.107 
.02658 
24.84 
d 23 46 
1 13 
10 
.107 
.01546 
14.44 
up with pa- 
per. 
VIII 
39 600 
300 
375 
0 15 
1 5 
10 
51 
92 
.54 
.107 
.01626 
15.2 
Moderate wind. 
IX 
41 600 
600 
450 
0 15 
1 30 
11 
55 
92 
.89 
,0. 
.01334 
11.53 
Do. 
Of the various proportions used that of 600 c. c. formalin, 300 c. c. 
water, and 375 gms. of permanganate gives the highest yield of for- 
maldehyde gas. 
In experiment I the determinations a and b, made simultaneously 
in the same time and on the same volume of air, gave the same results ; 
this would seem to indicate that the method of analysis, under the 
same conditions, gives constant results. In experiment III 5 liters of 
air in a were drawn in the same time as 10 liters in b, with practically 
the same result; this seems to point to the conclusion that 5 liters of 
air is a large enough quantity for a determination. 
In experiments IV, V, VI, and VII, the same proportions of 
materials were used to charge the room, but the results in IV are low 
on account of the brisk wind blowing at the time and should not be 
compared with those of V, VI, and VII. The three determinations of 
V, VI, and VII, which are comparable, show a fairly close agreement. 
VI and VII show the rate of leakage from the room, and d and e of VI 
and c and d of VII, which are comparable, show that when there is a 
very little wind the leakage from the room when pasted up with 
paper is not much less than when not so pasted. 
32507— No. 27—06 3 - 
