Anulijsis of the Cray Copper Ore of Alrthreij, 105 



analysed, the proportions of titanium and iron were nearly 

 equal, and that the uraniCim did not exceed four per cent. 

 The appearance of uranium surprised me a good deal. I 

 perceive, however, that it has iilready been detected in this 

 ore, from an analysis published by Professor Jameson, in 

 the second vohmie of his Mineralogy, which, I understand, 

 was made by Lauipadlus. The specimen examined byLam- 

 padius yielded very nearly 60 pans of titanium, 30 of iron, 

 and 10 of uranium. Whereas, in mine, if the foreign 

 matter be removed, there was obtained, very nearly, 



48 titanium J 



48 iron, 

 4 uranium, 



100 



But there can be no doubt, that the iserine which T ana- 

 lysed was still contaminated with a good deal of iroii-sand ; 

 for it was impossible to remove the whole. 



XVII. Analysis of the Gray Copper Ore of Jirthrey, in 

 Stirlingshire, By Thomas Thomson, M\D,, Edifi- 

 I'urgh *. 



JL HE copper mine of Airthrey, near Stirling, consists of a 

 thin vein, which runs through the west corner of the Ochils. 

 It has been twice wrought, by two different companies ^ 

 but, in both cases, was abandoned, after a few years' trjal. 

 I went to it some years ago, and examined the ore, at the- 

 -request of one of the proprietors. The specimens which 

 were employed for the subsequent analysis, were the purest 

 that I could select, out of a considerable quantity. I wag 

 told, however, that from the lower level, which was at that 

 time full of water, much richer ore had been extracted. 

 But, afterwards, when the lower level was free from its water, 

 I went down to it myself, and found the ore precisely of 

 the same kind as in the upper, with this difference, that it 

 was more mixed with calcareous spar, and perhaps, on that 

 account, more easily smelted. 



The veinstones in the Airthrey mine are sulphate of ba- 

 rytes and carbonate of lime, and with these the ore i» al- 

 iiio<it always more or less mixed. 



Tlie colour is at first light steel-gray; but the surface 

 foon tarnishes, and becomes of a dark dull leaden-gray, 



• From Transactions of Royal Society, Edinburgh, 18Q7, 



and 



