496 Mr. E. Schunck on Lecanorin 



sufficiently elucidated the subject. Some obscurities, however, 

 in a part of Dr. Kane's late paper seemed to make it desirable 

 that some of his results should be confirmed before being 

 finally adopted, and at the suggestion of Professor Liebig I 

 undertook the re-investigation of this subject, and performed 

 it in his laboratory. 



Instead of the Roccella tinctoria I employed in my experi- 

 ments the lichens that grow on the basalt rocks of the Vogels- 

 berg in Upper Hessia, where they are collected for the pur- 

 pose of preparing a dye from them. Tiiese lichens were all 

 crustaceous and belonged to the genera hecanora, Vrceo- 

 laria, Variolaria, &c. From them I extracted the following 

 substances : — 



1. A white crystalline substance, soluble in alcohol and 

 aether but insoluble in water, bearing in its properties great 

 resemblance to the substance called by Heeren ILrythrin and 

 by Kane Erythrilhi, but different in composition, and giving 

 other products of decomposition. This substance I call Le- 

 canorin. 



2. A crystallizable substance identical in pi'operties and 

 composition with Heeren's Pseuderythrin and Kane's Eryfhrin. 



3. A fatty substance of acid properties, soluble in alcohol 

 but insoluble in aether and water. 



The method by which these substances were extracted and 

 separated from one another, was the following. The lichens 

 were reduced to a coarse powder and then treated with Eether, 

 in an apparatus of displacement, until the aether dissolved no- 

 thing more. The aelhereal extract, which had acquired a 

 green tinge from chlorophyll in solution, was distilled off, 

 leaving as a residue a greenish yellow mass, consisting for the 

 greater part of lecanorin. This mass was brought into a glass 

 funnel and washed with small quantities of aether, until it had 

 lost its green colour in part. It was then treated with boiling 

 water in order to remove every trace of pseuderythrin, and, 

 lastly, purified by dissolving it in a small quantity of boiling 

 alcohol, which deposited on cooling a snow-white crystalline 

 mass, consisting of lecanorin in a state of purity. The dark 

 green tethereal fluid obtained by washing the impure lecanorin, 

 contained besides lecanorin the greatest part of the pseudery- 

 thrin which had been extracted by the aether. The fluid was 

 evaporated to dryness and the residual mass treated with boil- 

 ing water, which deposited on cooling a mass of shining plates 

 and needles of pseuderythrin, which was purified by re-cry- 

 stallization. More of this substance was obtained by treating 

 the lichens, which had been exhausted with aether, with boil- 

 ing alcohol and filtering rapidly. The alcohol was distilled 



