348 Mr. Hatchett's Experiments on Zoophytes, 



The acid in which they had separately been steeped, did not 

 afford any precipitate by the addition of the alkalies ; and the 

 only change was in the colour, which became deep yellow when 

 ammoniac was added. 



The Gorgonia now to be mentioned, differ from the former, 

 as they are not coated with a fleshy or pulpy cortical substance. 

 They are here placed immediately before the Antipathes, on 

 account of their great similarity in chemical properties, as well 

 as in external appearance. 



Gorgonia Antipathes. 



Some pieces of this Gorgonia were immersed in dilute nitric 

 acid during three weeks, at the end of which time they were 

 much softened, and appeared to be composed of a pale brown, 

 opaque, membranaceous substance, which formed concentrical 

 coats, of a ligneous aspect. 



The acid in which these pieces had been steeped, was become 

 pale yellow, and changed to orange colour when ammoniac 

 was added; but not the smallest precipitate could be thus 

 obtained ; nor was any alteration caused by the addition of 

 lixivium of potash. 



When distilled water was boiled with the Gorgonia Antipathes 

 during about six hours, it became slightly tinged with yellow ; 

 and, some infusion of oak bark being added, a small quantity of 

 gelatin was precipitated. 



The pieces of this substance which had been thus treated, 

 were afterwards boiled with lixivium of caustic potash, by which 



brown, when subsequently steeped in pure ammoniac ; and, in the course of a few 

 hours, they were completely dissolved. 



