316 DR. KANE ON THE CHEMICAL HISTORY OF ARCHIL AND LITMUS. 
This formula, C 18 H 10 N O g + 3 Zn O + 4 aq, is completely analogous to that of 
the betaorceinate of copper, which was found to be C 18 H 10 N O g + 3 Cu O + 4 aq. 
The white orceinate of zinc differs from the purple variety in containing two equiva- 
lents of oxygen less, but the above analyses cannot be considered as fully deciding 
whether the substance in an anhydrous form is expressed by the formulae C 18 H 12 
N O s , or C 18 H 10 N 0 6 . To obtain more complete evidence, leucorceinate of zinc 
(the same specimen as that analysed) was exposed in Liebig’s apparatus to a stream 
of dry carbonic acid in an oil bath, heated to 280° of Fahr., until long after all traces 
of water had passed away, and the bulb-tube containing the substance had ceased to 
lose weight. In this experiment 0*547 of material gave 0*030 of water, being 5*48 
per cent., and the remaining 0*517 gave, by careful ignition until all organic matter 
was removed, moistening with nitric acid, and ignition a second time until all traces 
of nitrous fumes were driven off, 0*193 gramme of oxide of zinc, corresponding to 
35*39 per cent. Taking the dry leucorceine as C 18 H 10 N O s + 2 H, the numbers are 
Theory. 
Experiment. 
1 Leucorceine 
199*9 
59*00 
59*13 
2 Water . . 
18*0 
5*31 
5*48 
3 Oxide of zinc 120*9 
35*69 
35*39 
338*8 
100*00 
100*00 
The quantity of oxygen separable in the form of water, is therefore fully shown to 
be two equivalents, and hence the formation of the leucorceine is due to the fixation 
of hydrogen in the new body, and not to the abstraction of oxygen from the old. 
When a solution of protochloride of tin is added to azolitmine dissolved in water 
of ammonia, a fine purple precipitate falls, which having been well washed and dried 
in a temperature of 212° in Liebig’s apparatus, was analysed as follows. 
0*547 gramme ignited and treated with nitric acid, as in former instances, gave 
0*231 of peroxide of tin. 
0*631 gramme gave 0*202 of water, and 0*681 of carbonic acid. 
The formula deducible from these results is C 18 H 12 N 0 12 + 2 Sn O, this salt 
containing only one half of the protoxide of tin existing in the protazolitmate of tin, 
described under the head of azolitmine. The numerical results are 
18 Carbon . 
Theory. 
Experiment. 
109*8 
30*03 
29*86 
12 Hydrogen 
12*0 
3*28 
3*55 
1 Nitrogen . 
1 4 Oxygen . 
14*1 
112*0 
3*85 "I 
30*63 J 
33*37 
2 Tin . . 
117-8 
32*21 
33*22 
365*7 
100*00 
100*00 
