ABSOEPTION OP VAEIOUS LIQUIDS. 
871 
Table II. — Diactinic Power of Liquids. 
Thickness of stratum 0‘75 inch. 
Name of substance. 
1 
Termination 
of spectrum. 
Relative 
lengths of 
spectra. 
Remarks. 
Water 
170-5 
116-5 
74-0 
20-0 
Wood-spirit 
With a faint impression of the rays about 156. 
Alcohol 
159-5 
116-5 
63-0 
Fousel Oil 
20-0 
Gl3’col 
107-5? 
114-5 
1 1-0 ? 
Slight einpyreumatic odour. 
Glycerin 
18-0 
Ether 
112-5 
16-0 
Chloroform 
122-5 
26-0 
Dutch Liquid 
132-5 
36-0 
Oxalic Ether 
115-5 
19-0 
8-0 
Carbolic Acid 
104-5 
Benzol (C,. 
117-5 
21-0 
Paraffin Oil, ^(CjH^) 
lli-5 
15-0 
Specific gravity 0-831. Boiling-point 360'’. 
Oil of Turpentine 
104-5 
8-0 
Phosphorus (melted) 
0 
Slight yellowish tinge. 
Bisulphide of Carbon 
102-5 
6 
Oxychloride of Phosphorus 
0 
Terchloride of Phosphorus 
0 
Retaining a little phosphorus in solution. 
Terchloride of Arsenic 
101-5 
5-0 
Acetic Acid 
112-5 
16-0 
Glacial. 
Sulphuric Acid 
160-5 
64-0 
Nitric Acid 
106-5 
10*0 ' 
Specific gravity T3. 
Specific gravity 1-1. 
Hydrochloric Acid 
152 5 
56-0 ! 
The starting-point for each spectrum was 96 '5 upon the scale already adopted. 
Of all these liquids, water and alcohol are the only two, except sulphuric and hydro- 
chloric acids, which are strongly diactinic ; water is eminently so, alcohol in a much less 
degree. No relation in this respect is traceable between common alcohol and the other 
alcohols examined, viz., wood-spirit, fousel oil, glycol, glycerin, and the phenic alcohol 
carbolic acid. Bisulphide of carbon, the refractive medium employed in my earlier 
experiments, is singularly deficient in diactinic power, and is therefore eminently unfit 
for such researches. 
c. Absorption of Chemical Bays by transmission through Gases and Vapours. 
17. In the experiments upon the absorbent action of aeriform media, the gas or vapour 
under trial was introduced into a brass tube 2 feet long, blackened on the inside, and 
closed at the end by plates of quartz, which were fitted on so as to form air-tight joints. 
The tube could be attached by a stopcock to the plate of the air-pump, and after 
exhausting the air any gas could be easily introduced. In cases in which the gas was 
liable to act upon the metal, a glass tube was substituted for the metallic one, and the 
gas was introduced by displacement. The tube when prepared was interposed at t, fig. 1 
(par. 6), between the slit s and the prism b, and the rays emanating from the electric 
spark were, after traversing the column of gas contained in the tube, received first upon 
the prism and lens, and then upon the excited collodion surface, in the usual manner. 
6 c2 
