PROXIMATE PRINCIPLES OF SOME OF THE LICHENS. 
395 
0*1798 substance gave 0*403 carbonic acid and 0*081 water. 
Calculated numbers. Found. 
per cent. I. II. 
III. 
36 C 2700 
61*02 
60*81 
61*16 
61*12 
18 H 225 
5*09 
4*90 
5*20 
5*00 
15 0 1500 
33*89 
34*29 
33*64 
33*88 
4425 
100*00 
10000 
100*00 
100*00 
These numbers therefore give C^g H^g as the formula of gyrophoric acid. 
Ether compound. 
When gyrophoric acid is boiled for some hours in strong spirits of wine it is readily 
converted into an ether, a considerable quantity of a resinous matter and orcine being 
also formed during the operation. The ether is very soluble in hot water, and is puri- 
fied from adhering resinous matter exactly in the same way as the ethers of the orsellic, 
lecanoric and analogous acids, which in its external properties it very closely re- 
sembles. 
I. 0‘2532 grm. ether dried in vacuo, gave with chromate of lead 0‘570 Co^ and 
0*144 Ho. 
II. 0*2/8 substance gave 0*625 carbonic acid and 0*155 water. 
Calculated numbers. Found numbers. 
C 40 
3000 
61*39 
I. 
61*33 
II. 
61*31 
H23 
287 
5*87 
6*31 
6*19 
0 16 
1600 
32*74 
32*36 
32*50 
4887 
100*00 
100*00 
100*00 
These numbers give C 35 Hjg O^g-f C 4 Hg O 4 as the rational formula of the gyro- 
phoric ether. 
Gyrophoric acid also readily forms a corresponding methyl compound when it is 
boiled for some hours with wood-spirit. In all its characters it perfectly agrees with 
the analogous compounds of lecanoric and orsellic acids. 
Gyrophoric acid dissolves very readily in a slight excess of baryta, and when the 
solution is supersaturated by an acid the gyrophoric acid precipitates unchanged. A 
quantity of gyrophoric acid was dissolved in a cold solution of baryta and the excess 
of the base removed by a stream of carbonic acid. The precipitate, which consisted 
of a mixture of carbonate of baryta and the organic salt, was collected on a filter and 
dried by a gentle heat. The dried precipitate was then repeatedly digested in strong 
spirits of wine, in which the organic salt dissolved, though with difficulty, the car- 
bonate of baryta remaining on the filter. On standing for some time, the clear solu- 
tion deposited the baryta compound in silky crystals. This salt is insoluble in cold 
alcohol. The hot spirits appear to have partially altered it, for on subjecting it to 
analysis, though it appeared to have an uniform composition, yet on decomposing it 
