§44 Mr. Hatchett's Experiments on Zoophytes, 



lime, which serves to cover and defend it, in the manner of a 

 shell.* 



Gorgonia suberosa. 



The cortical part of this Gorgonia was separated from the 

 stem, and was first subjected to experiment. 



Some portions of this cortex were immersed in dilute nitric 

 acid ; and, after an effervescence which continued several hours, 

 a soft yellowish membranaceous substance remained, retaining 

 the original figure. 



The liquor, when decanted, was pale yellow, which colour 

 was much deepened by the addition of ammoniac ; at the same 

 time, a small quantity of phosphate of lime was deposited. 



A considerable portion of carbonate of lime was afterwards 

 precipitated by carbonate of potash. 



Some pieces of the cortex were boiled with distilled water 

 during about six hours ; and, to the filtrated liquor, infusion of 

 oak bark was added, by which, a large quantity of gelatin was 

 precipitated. 



The same pieces were afterwards boiled with lixivium of 

 caustic potash, which effected a perfect solution, and formed the 

 animal soap of Chaptal ; at the same time, the calcareous matter 

 subsided to the bottom of the matrass. 



The cortical part of this Gorgonia, when put into a red-hot 

 crucible, emitted much smoke, with a smell like horn that is 



* It may here be proper to observe, that the membranaceous part of all these sub- 

 stances, such as the Madrepores, Millepores, f lustra, &c- £sfc. was dissolved, when 

 these bodies were boiled with lixivium of caustic potash ; and animal soap was formed. 



The same may also be said of shells ; and Mr. Van Mons has noticed this effect on 

 those of the oyster. See Annaks de Chimk, Tome XXXI. p. 123. 



