94 



of grapes made me think that each bundle was composed of 

 fibres formed from its centre (as some of the smaller ones 

 are). : but on opening some of them we found an ochraceous 

 gravelly substance in the middle, from which they diverged 

 more or less regularly, often more dense and hard inwardly 

 than outwardly. The more regular ones are commonly 

 more white and satiny than the others, excepting towards 

 the tips, and are more of the texture of rotten wood. The 

 outsides are very tender, and easily bruised. According to 

 the analysis of Mr. Chenevix, this species contains 



Oxide of copper 54 



Arsenic acid 30 



Water 16 



100 



Haiiy mentions capillary arseniate of copper, v. 3. p. 578. 

 and observes "that foreign mineralogists have found different 

 regular forms of arseniate of copper, which from certain cir- 

 cumstances he has not yet been able to determine. " The 

 lower magnified Jigure shows some of the fibres or filaments 

 of both sorts here mentioned, some of which are collapsing 

 at their points as if they had been wetted, forming various 

 reticulations and indentations of a purplish hue, apparently 

 retaining that colour from being less exposed to rubbing or 

 any other accident. This was found in Huel Gorjand mine 

 in Cornwall, from whence most of the other arseniates of 

 copper come. 



