356 PROFESSOR TYNDALL’S CONTRIBUTIONS TO MOLECULAR PHYSICS. 
Table XXX. 
Radiation through dry Carbonic Acid. Source, carbonic-oxide flame. 
Tension in inches. 
Deflection. 
Absorption. 
1-0 
33-7 
53-0 
2-0 
37-0 
61-7 
3-0 
38-6 
66-9 
4*0 
39-4 
70-0 
5-0 
40-0 
72-3 
10-0 
41-4 
78-7 
About four months subsequent to the performance of these experiments they were 
repeated, using as a source a much smaller flame of carbonic oxide. The absorptions 
were found somewhat less, but still 
very high. They follow in the next Table. 
Table XXXI. 
Radiation through dry Carbonic Acid. Source, 
small carbonic-oxide flame. 
Tension in inches. 
Deflection. 
Absorption. 
1-0 
O 
17-3 
48-0 
2-0 
.20-0 
55-5 
3 - 0 
21-7 
60-3 
4-0 
22-8 
65-1 
5-0 
24-0 
68-6 
10*0 
26-0 
74-3 
For the rays emanating from the heated solids employed in all my former researches, 
carbonic acid proved to be one of the most feeble absorbers ; but here, when the waves 
sent into it emanate from molecules of its own substance, its absorbent energy is enormous. 
The thirtieth of an atmosphere of the gas cuts off half the entire radiation ; while at a 
tension of 4 inches, nearly 70 per cent, of the whole radiation is intercepted. 
The energy of olefiant gas, both as an absorbent and a radiant, is well known ; for 
the solid sources of heat just referred to, its power is incomparably greater than that of 
carbonic acid ; but, for the radiation from the carbonic-oxide flame, the power of olefiant 
gas is feeble when compared with that of carbonic acid. This is proved by the experi- 
ments recorded in the following Table : — 
Table XXXII. 
Radiation through dry Olefiant Gas. Source, carbonic-oxide flame. 
Tension in inches. 
Deflection. 
Absorption. 
1 
17-0 
24-2 
2 
26-0 
37-1 
4 
33-0 
49-1 
Potal heat . 
. 47-3 
100-0 
