1871.] Dr. J. Stenhouse on Fucusol. 81 



Fucusol. 



I have found that when seaweeds were boiled with very dilute sul- 

 phuric acid, containing about 3 per cent, of acid, that a substance cor- 

 responding to that described by Gudkow was obtained, which, when 

 distilled with sulphuric or hydrochloric acid, yielded fucusol. In my 

 paper of the year 1850 I have described the difference in the physical 

 properties of furfurol and fucusol, and also the difference between the pro- 

 ducts obtained by the action of ammonia upon them and the bases derived 

 from these. I have again repeated the examination of these substances 

 with great care, and find my former statements to be correct. In addition 

 to these, I have recently prepared the aniline compound analogous to fur- 

 furaniline *. Fucusaniline hydrochlorate crystallizes in needles of a mag- 

 nificent purple colour, and closely resembles the corresponding furfurol 

 compound. 



As is well known f, when furfurol is boiled with water and silver 

 oxide, metallic silver is deposited and silver pyromucate formed, the latter 

 remaining in solution. In a similar manner I found that when fucusol was 

 digested at 100° C. for five or six hours with an excess of recently pre- 

 cipitated silver oxide and a considerable quantity of water, its odour gra- 

 dually disappeared, and at the completion of the reaction a silver-salt was 

 found in solution, whilst metallic silver was deposited, partly in a gra- 

 nular state and partly as a mirror, on the bottom of the flask. Sufficient 

 hydrochloric acid was then added to the hot filtered solution to precipi- 

 tate the silver. After the removal of the argentic chloride it was care- 

 fully evaporated at a temperature below 100° and the brown semi- 

 crystalline mass thus obtained boiled with light petroleum-oil, which dis- 

 solved the acid and left the colouring-matter. One or two crystalliza- 

 tions from boiling water rendered it quite pure. 



Analysis. 



•1N8 grm. substance gave *370 grm. carbonic anhydride and -080 grm. 



water. 



Theory. Found. 



C 5 CO 53-56 53-68 



H 4 4 3-57 4-25 



(h 48 42-87 



112 100-00 



From this analysis, it will be seen that this acid, which I propose to 

 call j3 pyromucic acid, is isomeric with ordinary pyromucic acid, from 

 which, however, it slightly differs in its physical properties. The melting- 

 point of pure /i pyromucic acid is 130°, being nearly the same as that of 

 the acid obtained from furfurol, which I found to be 133°, and which 



* Proc. Koy. Soc. vol. xviii. p. 5157. t Ann. Chem. Pharm. xol. cxvi. p. 259. 

 VOL. XX. H 



