VOL. XC.] PHILOSOPHICAL TRANSACTIONS. 717 



gorgonia was exposed to a red heat, it crackled, and emitted a thick smoke, with 

 the smell of burnt horn. The shape was soon destroyed, and a compact coal 

 remained. By continuing the red heat, a very small portion of white matter was 

 obtained, which, as far as the quantity would allow, was proved to be muriate of 

 soda, with some carbonate of the same. 



The last species of gorgonia which I shall here mention, is one which so much 

 resembles the gorgonia antipathes as not easily to be distinguished from it, and, 

 like the preceding, has probably been confounded with it ; but on closely com- 

 paring them, the gorgonia now treated of is found to be more fiat in the stem, 

 on the thin sides or edges of which a number of short spines or protuberances 

 are placed very near each other. That it is very different from the gorgonia anti- 

 pathes, will be proved by the subsequent experiments. Some pieces of this gor- 

 gonia were exposed to the action of dilute nitric acid for nearly 4 weeks. The 

 structure then became very apparent, and consisted of strong fibres, which were 

 placed nearly in a parallel direction, from one extremity of the branch to the 

 other, and, being closely arranged side by side, formed concentric coats of a pale 

 brown opaque substance ; but these coats were by no means so distinct as those 

 observed in the gorgoniae formerly mentioned, though like them the fibrous sub- 

 stance possessed the characters of membrane. The dilute acid in which these 

 pieces had been steeped, was become pale yellow, which changed to orange colour 

 when ammonia was added ; at the same time so large a quantity of phosphate of 

 lime was precipitated, that the liquor became thick and viscid. The phosphate 

 was separated by a filter ; and lixivium of potash was added to the clear liquor, 

 without producing any effect. 



This gorgonia was digested in boiling distilled water during 1 8 hours, and tinged 

 it with pale, yellow. Infusion of oak bark was then poured into the liquor, and 

 precipitated a small portion of gelatin. The pieces employed in the above ex- 

 periment were next boiled with lixivium of caustic potash, and formed a dark- 

 coloured animal soap ; at the same time the phosphate of lime was separated, and 

 was gradually deposited at the bottom of the matrass. Part of a large branch of 

 this gorgonia was exposed to a low red heat. It immediately emitted a thick 

 smoke, with the smell of burnt horn ; and after a long continued heat the phos- 

 phate of lime was left, so as to retain the original figure, like bone which has 

 been burned ; but, in the present instance, the particles of the mass cohered but 

 feebly. When this residuum was dissolved, and the phosphate separated in the 

 usual manner, a slight cloud of carbonate of lime was produced by potash. 



Antipathes Ulex. — When this had been immersed 14 days in dilute nitric acid, 

 it became transparent, and so much softened, that from a horny substance it now 

 nearly resembled cartilage. The acid in which it had been steeped, changed to a 

 very deep yellow or orange colour when ammonia was added ; but no precipitate 

 could be obtained by this, or by potash. A portion of this antipathes was di- 

 gested with boiling distilled water, from which some gelatin was precipitated after- 



