86 
PROF. T. CARNELLEY, MR. J. S. HALDANE, AND DR, A. M. ANDERSON 
These conclusions will be seen to follow from the accompanying Tables :— 
Carbonic 
Organic 
Total micro- 
No. of 
acid. 
matter. 
organisms. 
cases. 
Mean. 
Mean. 
Mean. 
With 2- 4 volumes Carbonic acid* . 
2-7 
5'6 
1-9 
56 
„ 4- 6 
5 ) 
55 
4-9 
6-1 
3-5 
27 
„ 6- 8 
5 5 
55 
7-3 
10-4 
29 -7 
25 
„ 8-10 
55 
55 
8-9 
9-5 
33-5 
26 
„ 10-12 
55 
55 
11-1 
11-4 
79-6 
29 
„ 12-15 
55 
55 
13-3 
11-8 
36-3 
27 
„ 15-20 
55 
55 
17-0 
13-0 
137-0 
31 
„ 20-30 
55 
55 
22-9 
13-6 
82-0 
12 
,, 30 and above 
55 
37-1 
19-8 
53-0 
9 
With 0- 2'8 volumes of Oxygen requir 
ed for organic matter 
4-3 
1-6 
5-3 
21 
„ 2-8- 5-6 
55 
55 
5 5 5 5 
6-8 
4-2 
10-1 
52 
„ 5-6- 8-4 
55 
5 5 
5 5 5 5 
9-7 
7-2 
34-1 
58 
„ 84-11-2 
55 
55 
5 5 55 
10-7 
9-7 
29-2 
24 
„ 1P2-14-0 
55 
55 
5 5 5 5 
11-9 
12-6 
88-3 
31 
„ 14-0-16-8 
55 
55 
5 5 5 5 
16-0 
15-4 
571 
17 
„ 16-8-22-4 
55 
55 
5 5 5 5 
18-5 
19-3 
145-0 
17 
,, 22‘4 and above 
55 
5 5 55 
18-8 
29-7 
87-0 
15 
In the first, the other constituents are compared with the carbonic acid as standard; 
in the second, with the organic matter as standard. 
Circumstances affecting the Organic Matter in Air. 
The most important circumstances which suggest themselves as likely to affect 
the amount of oxidisable .organic matter in ah’ are the following :—(1) Combustion 
of coal, (2) ditto of coal gas and of oil, (3) respiration, (4) dust, (5) physical exercise, 
(6) cleanliness. 
1. Combustion of Coal. —A close connexion is traced between the amount of organic 
matter present in air and the combustion of coal. This point has been investigated 
by one of us in conjunction with Mr. Wm. Mackie ('Roy. Soc. Proc.,’ vol. 41, p. 238), 
and as a result of that investigation it was found that in town the organic matter was 
lowest during the night, rather higher in the morning (5 A.M. to 10 A.M.), con- 
siderably higher in the middle of the day (10 A.M. to 3 P.M.), and higher still towards 
evening (3 p.m. to 8 p.m.), after which it decreased. It is generally rather high in the 
early morning (5 a.m. to 7 a.m.), when fires are being lit, and the black smoke of 
incomplete combustion discharged from the chimneys (compare pp. 65-69; also 
Parkes, p. 117). 
In examining the air of a room for organic matter, it is therefore necessary also to 
determine the condition of the outside air at the same time. 
2. The Combustion of Coal Gas does not appreciably increase the quantity of organic 
* Compare Parkes, 6tli edit., p. 116. 
