888 Professor ConnelPs Analj/sis of the 



was first chemically examined by Mr Nuttal, who ascertain- 

 ed that it differs entirely in constitution from asbestus ; and 

 concluded from his experiments that it consists essentially of 

 magnesia and water, with a little oxide of iron and lime. It 

 was subsequently examined by Dr Thomson, according to 

 whom, it also contains 12J per cent, of silica. The consti- 

 tuents the latter found to be :•— 



99-829* 

 Having lately obtained small specimens of thi^ mineral 

 from the locality of Hoboken, in America, I subjected them 

 to analysis, and obtained a result differing in some respects 

 from both the previous. 



The specimens examined by me had the ordinary external 

 characters of nemalite, consisting of adhering fibres of a 

 fine silky lustre, and white colour, with a shade of yellow and 

 partial slight blue or green tinge. Their matrix was ser- 

 pentine, and in the analysis, any adhering particles of the 

 matrix were carefully removed. According to Mr Nuttal 

 and Dr Thomson, the mineral is soluble in acids, without 

 effervescence, at least in its fresh state. But on very care- 

 ful examination of what appeared to be perfectly fresh por- 

 tions of my specimens, there was sensible effervescence on 

 solution in acids, and this was still more manifest when the 

 experiment was performed in a tube, and a lens employed in 

 the observation. It appears to me, therefore, that carbonic 

 acid, although in much smaller quantity than in the native 

 carbonate of magnesia, is a constituent of the mineral, at 

 least of those specimens of it which I have obtained. Of 

 silica I found only a minute proportion, the mineral being 

 soluble in acids, with only an insignificant residue, particu- 

 larly when the acid is left some time on it. Mr Nuttal states 

 that it is soluble without any residue. The solution, when 

 made in a close tube, shewed protoxide of iron, with red prus- 



* Transactions Royal Society, Edinburgh, vol. xi. 



