DR. KANE ON THE CHEMICAL HISTORY OF ARCHIL AND LITMUS. 
289 
These numbers are confirmatory of the constitution of the substance as analysed 
when uncombined, and hence the formula given above may be looked upon as well 
established, although the number of analyses was limited to those above given, from 
the very small quantity of the substance which I obtained in a sufficiently pure con- 
dition. The connexion of this formula with that of the erythrine series is at once 
seen from the permanence of the twenty-two atoms of carbon which characterize 
that group of bodies, among which the erythryline appears to be that from which the 
azoerythrine is most directly and simply formed, in fact 
One equivalent of erythryline C 22 H 16 O 6 
One equivalent of ammonia ..... H 3 N 
Sixteen equivalents of oxygen ..... 0 16 
One equivalent of azoerythrine .... C 22 H 19 0 22 N. 
To explain the formation of azoerythrine from amarythrine, which is the highest 
member of the erythrine series by which we can consider it to be produced, we must 
suppose three equivalents of water to become fixed in the substance, thus : 
One equivalent of amarythrine .... C 22 H 13 0 14 
One equivalent of ammonia H 3 N 
Three equivalents of water H 3 O 3 
Five equivalents of oxygen O 5 
One equivalent of azoerythrine .... C 22 XT 19 0 22 N. 
The fixation of these three equivalents of water in a form not capable of being 
separated by combination with oxide of lead, appears to me not very likely, but if they 
could be eliminated, and that the formula of dry azoerythrine became C 22 H 16 O iy N, 
a difficulty in the theory of the production of orceine would be removed, the nature of 
which will hereafter be pointed out. It is possible that the analysis of a more basic 
salt of lead, or of a salt of silver, might demonstrate that these three equivalents of 
water may be replaced, or that even by a higher temperature they might be removed. 
II. Of Orceine. 
This substance, as prepared by the process already described, is of a fine red co- 
lour, very sparingly soluble in water, which however it colours a very beautiful pink, 
and from which it is precipitated totally on the addition of any soluble neutral salt. 
It is copiously soluble in alcohol, the solution being of a splendid crimson colour, and 
being precipitated by the addition of water. It is but very sparingly soluble in ether. 
Orceine dissolves easily in a watery solution of potash or of ammonia, giving a mag- 
nificent purple liquor, the colour of ordinary archil, from which the colouring matter 
may be totally removed by the addition of an excess of common salt. An alkaline 
orceinate gives with metallic salts, lakes of very beautiful purple of various shades, 
which however lose a great deal of their lustre on being dried. 
On commencing the analysis of this substance, I was met by a degree of discord- 
mdcccxl. 2 p 
