308 DR. KANE ON THE CHEMICAL HISTORY OF ARCHIL AND LITMUS. 
that I know of, and consequently it is not until all the labour of preparation and 
analysis has been gone through, that any opinion can be formed as to which sub- 
stance, or what mixture of the two substances, was present. The simplest analytical 
means consist in collecting the mixed gases produced by the combustion of the spe- 
cimen, and determining the relation by volume between the carbonic acid and the 
azote : if it be 18 : 1, the substance is pure azolitmine ; if there be no azote, it is pure 
spaniolitmine, which occurs but very seldom; and, if, as is generally the case, the pro- 
portion is thirty, forty, or fifty to one, the substance is a mixture on which it is use- 
less further to experiment. So rare is the presence of this body in a form, even nearly 
pure, that out of more than forty trials I obtained it in a state to justify its being 
made the object of quantitative investigation only twice. In one of these the absence 
of azote was complete, in the other a small quantity of azote remained, being 1 to 
200 of carbonic acid, a proportion so small that it could not interfere with the ana- 
lytical results. 
The spaniolitmine resembles azolitmine and erythrolitmine, in being turned blue by 
alkalies. It is of a bright red colour, insoluble in alcohol and in ether, and very 
sparingly soluble in water, which it tinges bright red. In this respect it differs some- 
what from the azolitmine, which is more soluble in water, and colours the water a 
darker and browner red. Its compound with ammonia is decomposed by a very 
moderate heat, although imperfectly, like the other bodies already noticed. Its pre- 
cipitates with metallic solutions are identical in appearance with those formed by the 
azolitmine. 
The analysis of this substanee was as follows : 
0 - 311 gramme of spaniolitmine dried in Liebig’s apparatus with an oil bath at 250° 
Fahr., gave 0-501 of carbonic acid, and 0-087 of water. 
Hence results the formula C 18 H 7 0 16 , giving 
18 Carbon . 
. = 109-8 
Theory. 
44-85 
Experiment. 
44-54 
7 Hydrogen 
II 
■M 
6 
2-86 
3-11 
16 Oxygen . 
. = 128-0 
52 29 
52-35 
244-8 
100-00 
100-00 
A very fine purple lead salt, which had been dried at 250°, gave the following results : 
From 2'648 of material were obtained 1'226 of carbonic acid, and 0"261 of water. 
1‘261 of material gave 0T58 of oxide of lead, and 0’661 of metallic lead. 
The formula C 18 H 7 0 16 + 5 Pb O gives 
18 Carbon . . . 
Theory. 
Experiment. 
109-8 
13-69 
12-81 
7 Hydrogen . . 
7-0 
0-75 
1-09 
16 Oxygen . 
128-0 
15-97 
16-10 
5 Oxide of lead . 
558-0 
69-59 
70-00 
802-8 
100-00 
100-00 
