296 DR. KANE ON THE CHEMICAL HISTORY OF ARCHIL AND LITMUS. 
however, it tinges pink : totally insoluble in oil of turpentine, but abundantly soluble 
in alcohol and ether. It dissolves in alkaline liquor, forming a fine purple (crimson) 
coloured solution, and is precipitated therefrom by an acid or a neutral salt. It forms, 
with metallic oxides, crimson lakes. 
By careful trial it was found that the erythroleic acid contains no nitrogen. 
0*318 gramme gave on analysis 0744 gramme of carbonic acid, and 0-26/ of 
water. 
The formula C 26 H 22 0 8 is thereby indicated, giving 
26 Carbon . . 
Theory. 
158*6 64*84 
Experiment. 
64*70 
22 Hydrogen . 
22*0 
9*00 
9*33 
8 Oxygen . . 
64*0 
26*16 
25*97 
244*6 
100*00 
100*00 
A quantity of a very fine crimson-purple coloured compound of this substance with 
oxide of lead was prepared with the remaining quantity which I possessed of this 
substance, and having been dried in Liebig’s apparatus with an oil bath at 250°, it 
was analysed. 
0*5 78 gramme of material gave 0*913 of carbonic acid, and 0*325 of water. 
0*255 gramme of material gave 0*061 of metallic lead, and 0*015 of oxide of lead. 
The resulting formula is C 26 H 22 0 8 + Pb O, giving 
26 Carbon . . . 
Theory. 
158*6 44*53 
Experiment. 
43*41 
22 Hydrogen . . 
22*0 
6*18 
6*24 
8 Oxygen . . . 
64*0 
17*96 
18*71 
1 Oxide of lead . 
111*6 
31*33 
31*64 
356*2 
100*00 
100*00 
Besides the analysis of erythroleic acid, above detailed, I examined a great number 
of specimens which gave results, variable in the per cent, proportions, but indicating 
the constant relation between the carbon and hydrogen of twenty-six atoms to twenty- 
two atoms, whilst the source of the variations lay in the proportion of oxygen not 
being constant. The per cent, proportion of carbon was generally higher, and that 
of oxygen as much lower than the numbers given by the analysis which has been 
brought forward, which indeed I selected as showing the maximum of oxygen, which 
I found this crimson substance soluble in ether to contain. This inconstancy in the 
constitution of erythroleic acid, arises from the occasional presence of another sub- 
stance, also crimson, semifluid, and soluble in ether, which I term erythroleine, and 
which I shall describe in detail hereafter. These two bodies are related to each other 
nearly as the two orceines, and like them are distinguishable only by analysis. 
In order to trace the origin of this remarkable substance, which from the minute 
quantity in which it exists is evidently a collateral product, it is necessary to recur to 
