left a Hack pafle. Ammonia feparated a brown matter in Analyfis of fol-^ 

 ffpall quantity from the clear folution ; and this matter, when Tf?"* ,.:j 

 calcined, did not lofe its colour. It was alraoft totally foluble 

 in muriatic acid, and this folution gave a black precipitate with 

 nut-galls, and a blue with alkaline prufiiate. The Hani tP 

 which the ammonia h^d been added, gave a grey precipitate 

 ty pot-afli. This retained its colour when ignited, and wa> 

 again I'oluble in muriatic acid with effervefcence. 6. Cau^tc 

 pot-afli poured on the refidue of fpiders' webs previoufly treat- 

 ed with yvater and alcohol, difengages a little ammonia, an^ 

 partly diflblves the matter. An acid throws down from this 

 folution a black pulvurelent taftelefs precipitate, which flightly 

 putTs up by heat, and leaves by deficcation a brittle and appa- 

 rently refinous matter. Its quantity is about one-twelfth of the 

 exhaufled matter made ufe of. It is partly foluble in volatile 

 oils. 



7. The aqueous extract of No. 3 being digefted with alco- 

 hol, gave out one-feventh part. This alcoholic extract was 

 brown, cpnfiderably deliquefcent, and of a (harp tafie. Jt 

 fwelled coniiderably on the coals, and at a certain period i% 

 burned rapidly, as if a nitrate were prefent. It effervefced 

 brilkly with fulphuric acid, giving out a white vapour of a 

 muriatic fmell. Poiafli and lime difengaged from this extra6t 

 a firongammonlacal fmell, and the vapours were very fenfible 

 on .the approach of muriatic acid. The extraft having been 

 incinerated, appeared by feveral experiments to contain mu- 

 riate of lime and a fulphate. What remained of the aqueous 

 extra6l after treatment with alcohol, was lefs deep in colour 

 than before, had a purvurelent appearance, and flightly pun- 

 gent tafte. On hot coals it did not fwell up, but left a very 

 abundant precipitate. Strong fulphuric acid poured on this 

 extract produced no fenfible fmell, and there was no produc- 

 tion of ammonia when it was triturated with quick-lime. 



8. Spiders' webs fubje£led to deftrudive diftillation, gave 

 firft water flightly coloured, but becoming deeper as the pro- 

 cefs went on ; and afterwards a black thick oil, with carbon- 

 ated hydrogen and carbonic acid. A very fenfible fmell of 

 ammonia was developed, and a relidual coal was left, amount- 

 ing to half the matter employed. The coal after incineration 

 left two-thirds of its weight, half of which was taken up by 

 muriatic acid, and the remainder feemed to be iilex and coally 



nlatter. 



