and Observations on the component Parts of Membi'ane. 34,7 



The ,Gorgoni<e which have been enumerated, much resemble 

 each other in the composition of their cortices, as well as in the 

 nature of their stems. 



In the cortex, the predominant hardening substance is car- 

 bonate of lime; but, in the stem, phosphate of lime is the chief 

 and almost the only earthy substance that is present. 



The following Gorgonice (although in like manner invested 

 by a cortex) are different, as they do not afford any phosphate 

 of lime. 



Gorgonia Umbraculum, 

 Gorgonia verrucosa, 

 and three other species not described, so much resemble each 

 other in their chemical characters, that it would be superfluous 

 to give a separate account of them. 



The cortical parts of these Gorgonice were separately immersed 

 in dilute nitric acid. An effervescence immediately took place, 

 and, after some time, they were found in the state of soft, 

 pulpy, yellowish white membranaceous bodies, retaining nearly 

 their original size and form. 



The acid solutions did not afford any phosphate of lime 

 .when ammoniac was added ; but a large portion of carbonate 

 of lime was precipitated by solution of potash. 



The stems of these Gorgonice, when immersed during 14 

 days or more in the dilute acid, were very little affected, ex- 

 cepting, that they became softer and transparent, so as to 

 approach the characters of cartilage or softened horn.* 

 > 



• The stems of the various Gorgonia, which had been thus softened by long 

 immersion in dilute nitric acid, became of a deep reddish orange colour, inclining to 



