PROXIMATE PRINCIPLES OF SOME OF THE LICHENS. 
67 
orcin with the deposition of a carbonate of the base, and the formation of a reddish 
colouring matter, from which the orcin can never be effectually freed. This subject 
will be again referred to in a subsequent part of the paper. Orsellesic acid gives a 
fugitive bluish red, or rather violet colour with hypochlorite of lime, thus differing 
from the reaction of orsellic acid, but not easily distinguishable from that of orcin 
with the same reagent. 
When orsellesic acid is dissolved in ammonia and exposed to the air, it yields a 
red colouring matter similar to orcein. The acid was dried at 212° Fahr. 
I. 0‘3313 grm. acid gave with chromate of lead 0*7045 carbonic acid and 0*1567 
water. 
II. 0*3301 grm. acid gave 0*7008 carbonic acid and 0*151 water. 
Calculated numbers. 
I. 
II. 
16 C 1222*960 
57*27 
57*99 
57*90 
9H 112*315 
5*26 
5*25 
5*08 
8 0 800*000 
37*47 
36*76 
37*02 
2135*275 
100*00 
100*00 
100*00 
These analyses give CigHg Oy+HO as the rational formula of hydrated orsellesic 
acid. 
{Alpha) Or sellesiate of Baryta. 
The baryta salt was prepared from crude orsellesic acid which had been carefully 
freed from adhering muriatic acid. The crude orsellesic acid was dissolved in hot 
spirits, to which small quantities of dry crystals of'baryta were cautiously added. 
The solution of the salt may be concentrated by evaporation so long as it is acid, but 
any excess of base must be avoided, as otherwise the acid would be decomposed and 
carbonate of baryta deposited. When the hot solution has been sufficiently concen- 
trated, it should be carefully neutralized while hot, and set aside to crystallize. The 
salt is exceedingly soluble both in water and in spirits. When evaporated to the 
consistence of a syrup, it crystallizes in small prisms ; but when the spirits have been 
much diluted, the salt is deposited in long four-sided prisms. Its aqueous solutions 
must be evaporated in vacuo. As the baryta salt is decomposed when kept at 212° F., 
it was also dried in vacuo. Six or seven days were required for this purpose, and it 
lost from seven to eleven per cent, of water, according to the strength of the spirits 
out of which it had crystallized. 
Per cent. 
I. 0*342 grm. salt gave 0*1407 carb. of baryta =0*1091 BaO=31*90 BaO. 
II. 0*221 grm. salt gave 0*091 carb. of baryta =0*0706 BaO=3T94 BaO. 
III. 0*293 grm. salt gave 0*120 carb. of baryta =0*0931 BaO=31*77 BaO. 
0*4915 grm. salt gave 0*7442 carbonic acid and 0*161 water. 
