354 Mr. Hatchett's Experiments on Zoophytes, 



same smell, and afforded a similar coal, which by incineration 

 left a very small residuum, consisting chiefly of muriate of soda, 

 occasionally mixed with some carbonate of lime, which was also 

 often discovered when the recent Sponges were immersed in 

 acids; but this, as well as the muriate of soda, is I believe 

 merely extraneous, and arises from small shells, parts of Ma- 

 drepores, and such like bodies, which are often visibly lodged in 

 the interstices of the Sponges. 



Lastly, the Sponges, when boiled with lixivium of caustic 

 potash, were completely dissolved, and, like the horny stems of 

 the Gorgonice, formed animal soap, more especially when the 

 part which is apparently insoluble in water, and which remains 

 after the gelatin has been separated, was thus treated, 



Alcyonium asbestinum. 



This, after being immersed during several hours in dilute 

 nitric acid, remained unchanged in figure; a feeble effervescence 

 was at first produced, and the reddish purple colour was de- 

 stroyed. 



The external part became pale yellow, and was a soft opaque 

 pulpy substance, within which was a stem, very similar in tex- 

 ture, but less soft, and which still appeared of a pale red 

 colour. 



When pure ammoniac was added to the filtrated solution, no 

 apparent effect was produced ; but carbonate of potash precipi- 

 tated a large quantity of carbonate of lime. 



When a piece of this Alcyonium was exposed to a low red 

 heat, it soon took fire, and emitted a smell like burned horn ; 

 after which, it retained its figure, and became white. Being dis- 

 solved in dilute nitric acid, some animal coal was deposited; 



