DR. KANE ON THE CHEMICAL HISTORY OF ARCHIL AND LITMUS. 293 
in a stove until it ceased to lose weight. It was of a very rich purple-brown colour. 
Its analysis took place as follows : 
1113 gramme dried in Liebig’s apparatus at a temperature of 212°, gave 0 - 997 of 
dry substance, indicating the presence of 10*6 water in 100 parts. 
0-721 gramme of the hydrated substance, ignited until all organic matter was com- 
pletely burned out, the resulting mixture of oxide and metallic copper moistened with 
nitric acid and again ignited, gave 0-209 gramme of oxide of copper, corresponding 
to 29*0 per cent, for the hydrated, and to 32-37 per cent, for the dried substance. 
0‘709 gramme of the dried substance gave 0*787 of carbonic acid, and 0-250 of water. 
These results indicate the formula C 18 H 14 N 0 12 + 3 Cu O for the substance dried 
at 212°, giving 
Theory. 
Experiment. 
18 Carbon . . . 
= 109-8 
31-14 
30-68 
14 Hydrogen. . . 
= 14-0 
3-96 
3-92 
1 Nitrogen . . . 
= 14*1 1 
31-22 
33-03 
12 Oxygen . . . 
= 96-0 / 
3 Oxide of copper. 
= 118-8 
33-68 
32-37 
352*7 
100-00 
100-00 
In this form the substance contained therefore still four atoms of water, the formula 
being really C 18 H 10 N O g -f 3 Cu O + 4 HO; and as dried at 150°, it appears to have 
contained four more, which should give 9‘3 per cent., or five more, which should give 
11*3 per cent, of hydrate water, the experimental result being 10-6. I consider it 
most likely that in the fresh precipitated form this compound is expressed by C 18 
H 10 N 0 8 + 3 Cu O + 9 H O. 
It may, therefore, be now considered as definitely fixed that the betaorceine is iden- 
tical with the orceine discovered by Robiquet and analysed by Dumas ; and that the 
formula C 18 H 10 N O g , proposed by Liebig, truly expresses its constitution. 
In the analysis of orceine Dumas obtained 55-9 per cent, of carbon, whilst the for- 
mula he adopted, C 16 H 9 0 7 N, required only 55*3. I would refer this to the presence 
of some alphaorceine, for indeed his results express the constitution of the mixtures 
of the two orceines which exist very generally in archil. In analysing mixed orceine 
the carbon generally falls between 56 and 57 per cent., and several times came out 
almost precisely what Dumas obtained ; but considering the almost constant co-ex- 
istence of alphaorceine, it is certain that the lowest value obtained in good analyses 
is that which assigns its true proportion. It is much rarer to find the carbon ap- 
proximating to the quantity contained in alphaorceine, and I met with pure alphaor- 
ceine only once out of the great number of specimens of archil I examined. Dumas 
supposed his formula to be confirmed by the analysis of the silver salt, which con- 
tained 58"6 of oxide of silver, whilst theory required 58 ; the true formula of a bi- 
basic salt giving the quantity of oxide of silver 54*0 per cent. I consider the differ- 
