362 PEOFESSOE TYNDALL’S CONTEIBUTIONS TO MOLECULAE PHYSICS. 
copious transmission when the spiral was employed. It will be seen that a transmission 
of 2 per cent, is here obtained through a layer of water O' 07 of an inch in thickness. 
Another series of experiments, also executed by my assistant, gave the following 
results of the radiation of a hydrogen-flame through layers of water of five different 
thicknesses : — 
Radiation through Water. Source, hydrogen-flame. 
Thickness of liquid. 
C ; ^ \ 
0-02 inch. (M)4inch. (LOT inch. O'ldinch. 0 - 27inch. 
Transmission per 100 . . . 5 - 8 2-8 IT 0-5 0-0 
Wishing to compare the radiation from a flame of ordinary coal-gas with that of our 
hydrogen-flame, I reduced the former to the dimensions of the latter. The flame thus 
diminished, had a blue base and bright top, and the whole of it was permitted to radiate 
through our series of liquids. The following results were obtained : — 
Table XL. — Radiation through Liquids. Source, small gas-flame. Thickness of 
liquid layer (H)7 of an inch. 
Name of liquid. 
Deflection. 
Absorption. 
From Table XXXIX. 
Chloroform .... 
. . . 28-7 
39-8 
49-3 
Bisulphide of Carbon 
. . . 36-0 
53-2 
27-7 
Iodide of Ethyl . . 
. . . 41-7 
72-3 
75-6 
Benzol 
. . . 43*4 
79*4 
82-3 
Amylene .... 
. . . 45-0 
86-1 
87-9 
Sulphuric Ether . . 
. . . 46-6 
93-3 
92-6 
Formic Ether . . 
. . . 46-6 
93-3 
93-5 
Alcohol 
. . . 46-8 
94*1 
Acetic Ether . . . 
. . . 46*9 
94-4 
93-9 
Water 
. . . 47-4 
97T 
100-0 
Total heat .... 
. . . 48-0 
100-0 
I have placed the results obtained with the hydrogen-flame in the third column of 
figures. For some of the liquids it will be observed that the absorption of the heat 
issuing from the small gas-flame is nearly the same as that of the heat issuing from the 
flame of hydrogen. A very remarkable difference, however, shows itself in the deport- 
ment of bisulphide of carbon, as compared with that of chloroform. For the small gas- 
flame chloroform is the most transparent body in the list ; it is markedly more transpa- 
rent than the bisulphide of carbon, while for the hydrogen-flame the bisulphide greatly 
excels the chloroform in transparency. The large luminous gas-flame previously experi- 
mented with differs also from the small one here employed. With the large flame, the 
absorption by the bisulphide is to that by the chloroform as 
100 : 121 , 
