66 
MR. STENHOUSE ON THE EXAMINATION OF THE 
{Alpha) Orsellate of Baryta. 
L 0‘593 grm. salt gave O' 149 carb. of barytes=0' 1156 BaO = 19‘49 per cent. BaO. 
II. 0'350 grm. salt gave 0'088 carb. of barytes =0‘0682 BaO= 19'49 per cent. BaO. 
III. 0'505 grm. salt gave 0’126 carb. of barytes =0-0977 BaO = 19-34 per cent. BaO. 
I. 0-1505 grm. salt gave 0-264 carbonic acid and 0-052 water. 
II. 0-5773 grm. salt gave r041 carbonic acid and 0-197 water. 
Found numbers. 
Calculated numbers. 
I. 
II. 
III. 
32 C 2445-9200 
50-01 
49-36 
49-18 
15 H 187T925 
3-82 
3-83 
3-79 
1 BaO 956-8800 
19-57 
19-49 
19-49 
19-34 
13 0 1300-0000 
26-60 
27-32 
27-54 
4889-9925 
100-00 
100-00 
100-00 
These analyses give C 32 
for the formula of orsellate of baryta. 
{Alpha) Orsellesic Acid. 
When the gelatinous precipitate thrown down from the lime solution of the lichen 
by muriatic acid, and which constitutes crude orsellic acid, is mixed with a little 
water, and is again cautiously neutralized by the addition of small quantities of lime 
or baryta, and boiled till the whole is dissolved, the orsellic acid quickly undergoes 
a rather singular decomposition. Great care must be taken that no excess of base 
is present, and the boiling continued till the solution becomes quite clear, which 
shows that the decomposition of the orsellic acid is complete. If the solution has 
been quite neutral, no precipitation of carbonate of lime takes place. The liquid is 
allowed to cool and is then filtered. It is next neutralized with muriatic acid, which 
throws down an abundant gelatinous precipitate, which is a new acid, to which I shall 
give the name of orsellesic acid. This precipitate is to be collected on a filter and 
washed with cold water to remove adhering muriatic acid. It is then to be dried 
and dissolved in weak spirits, out of which it readily crystallizes. It is to be still 
further purified by being digested with animal charcoal in water, which, for a reason 
to be presently mentioned, must not be allowed to boil. The acid crystallizes out of 
alcohol and water in perfectly white needle-shaped crystals arranged in stars. It red- 
dens litmus paper distinctly, and has a feebly acid and somewhat bitter taste. It is very 
soluble in alcohol, both hot and cold; is much more soluble in hot water than 
orsellic acid, and crystallizes out of its aqueous solutions in much larger crystals. 
When orsellesic acid is boiled in water it gives off carbonic acid, and is pretty rapidly 
converted into orcin, which, when the solution is concentrated, is deposited in per- 
fectly colourless crystals. About half an hour’s boiling is sufficient to convert any 
quantity of orsellesic acid into perfectly colourless orcin. When orsellesic acid, on 
the other hand, is boiled with an excess of lime or baryta, it is also converted into 
