PROFESSOR TYNDALL’S CONTEIBTJTIONS TO MOLECULAR PHYSICS. 
358 
The total heat radiated from the flame of Bunsen’s burner is greatly less than that 
radiated when the incandescent carbon is present in the flame. The moment the air is 
permitted to mix with the luminous flame, the radiation falls so considerably that the 
diminution is at once detected, even by the hand or face brought near the flame. Com- 
paring Tables XXIV. and XXV., we see that the radiation from the Bunsen’s burner 
is, on the whole, less powerfully absorbed than that from the luminous gas jet. In some 
cases, as in that of formic ether, they come very close to each other ; in the case of amy- 
lene, and a few other substances, they differ more markedly. But an extremely inter- 
esting case of reversal here shows itself. Bisulphide of carbon, instead of being first, 
stands decidedly below chloroform. With the luminous jet, the absorption of bisul- 
phide of carbon is to that of chloroform as 100 : 122, while with the flame of Bunsen’s 
burner the ratio is 100 : 56; the removal of the carbon from the flame more than doubles 
the relative transparency of the chloroform. The case is of too much interest to be 
passed over without verification : here is the result obtained with a different total heat : — 
Deflection. 
Absorption. 
Chloroform 
. 16-5 
8-4 
Chloroform 
. 16-0 
8-2 
Bisulphide of Carbon . . 
. 19-0 
9-7 
Bisulphide of Carbon . . 
. 19-4 
9-9 
Total heat 
. 68*4 
100-0 
And again, with an intermediate total heat, — 
Deflection. 
Absorption. 
Chloroform 
. 10-2 
8-4 
Chloroform 
. 10-0 
8-4 
Bisulphide of Carbon . . 
. 12-0 
9*8 
Bisulphide of Carbon . . 
. 11-8 
9-7 
Total heat 
. 60-0 
100-0 
There is therefore no doubt that, while in 
the case of a platinum 
spiral at all tempera- 
tures, of a luminous gas flame, and, more 
: especially, in the case 
of lampblack heated 
to 212° Fahr. the absorption of chloroform exceeds that of bisulphide of carbon, for the 
flame of Bunsen’s burner the bisulphide is the more powerful absorber of the two. The 
absorptive energy of the chloroform, as shown in Table XX., is more than three times 
that of the bisulphide, while in Table XXV. the action of the bisulphide is nearly twice 
that of the chloroform. We have here, moreover, another instance of the reversal of 
formic and sulphuric ether. For the luminous jet the sulphuric ether is decidedly the 
more opaque ; for the flame of Bunsen’s burner it is excelled in opacity by the formic. 
§ 10 . 
The main radiating bodies in the flame of a Bunsen’s burner are, no doubt, aqueous 
