134 Mr. Grai/ on some Species of Shells [Feb. 



solution of nitrate of silver. When heated, this compound 

 fuses, then detonates with considerable energy, and leaves 

 cyanuret of silver, which probably contains a mniimum of cya- 

 nogen. It contains no water. If its constitution be analogous 

 with that of the foregoing salt, it ought to be composed of 



Nitrate of oxide of silver 1 atom 38-79 



Cyanuret of silver 2 61-21 



'ioo-o6 



It ought, therefore, to contain 70-76 per cent, of metallic 

 silver. This was confirmed by an experiment in which 0-43 

 gramme of the salt, decomposed by muriatic acid, yielded me 

 0-387 gramme of fused chloride of silver, equivalent to 69-74 

 per cent of metallic silver. 



I made many attempts, but without success, to form analo- 

 gous compounds by boiling other metallic cyanurets in a solution 

 of nitrate of silver. Cyanuret of nickel, treated in this manner, 

 instantly gave cyanuret of silver, and nitrate of oxide of nickel : 

 a similar decomposition took place with cyanuret of zinc. Prus- 

 sian blue occasioned the evolution of nitrous gas, and there was 

 obtained a solution of nitrate of oxide of iron, and a precipitate 

 consisting of a mixture of oxide of iron and cyanuret of silver. 

 Cyanuret of lead yielded a solution of nitrate and subnitrate of 

 lead, and a black coloured precipitate, which the application of 

 nitric acid proved to consist of metallic silver and white cyanu- 

 ret of silver. Cyanuret of copper, boiled in a solution of nitrate 

 of silver, gave a precipitate consisting entirely of metallic silver. 

 Cyanuret of palladium, similarly treated, sustained no alteration. 



Article IX. 



A List and Description of some Species of Shells not taken Notice 

 of by Lamarck. By John Edward Gray, Esq. MGS. 



(To the Editors of the Annals of Philosophy .) 



GENTLEMEN, British Museum, Jati. 10, 1825. 



In the following list I have referred several species, which 

 have not been taken notice of by Lamarck, to his genera, and 

 have described some new ones that are contained in the collec- 

 tion in the British Museum, where most of the species are exhi- 

 bited with the names, here adopted, attached. 



Your obedient servant, 



J. £. Gray. 



