874 
PROFESSOE W. A. MILLER ON THE PHOTOGRAPHIC 
21. The most interesting fact, however, disclosed by these various experiments is the 
persistence of either the diactinic or the absorbent property in the compound, whatever 
be its physical state — a circumstance which proves that the property under consideration 
is intimately connected with the atomic or chemical nature of the body, and not merely 
with its state of aggregation. 
The following diagram represents approximatively the relative position of the portions 
of the spectrum transmitted in a few of the cases described in the foregoing section of 
this paper. No attempt is made to indicate partial absorption of the rays. In one or 
two instances, where complete absorption at a particular part of the spectrum occm's, this 
has been indicated by an interruption in the line. 
Belative absorptive action of various Media upon the Electric Spectrum of Silver. 
Scale of Millimetres 0 
10 
20 
30 
40 
50 
60 
70 
Quartz-train, Silver spectrum 
Ice, Water, Fluor-spar . 
Rock-salt 
Bromide of Sodium 
Iodide of Sodium 
Nitrate of Soda . 
Carbonate of Soda 
Sulphate of Soda 
Sulphite of Soda . 
Hyposulphite of Soda 
Flint-glass 
Thin glass for Microscope 
Mica 
Alcohol 
Ether 
Benzol 
Bisulphide of Carbon 
Acetic Acid . . 
Oxalic Acid . . . 
Tartaric Acid . 
Citric Acid . . . 
Coal-gas .... 
Sulphurous Acid Gas 
Hydrochloric Acid Gas 
Hydrobromic Acid Gas 
Hydriodic Acid Gas . 
Chlorine .... 
Bromine .... 
Iodine 
Saturated 
solutions. 
Saturated 
solutions. 
