96 



was once thought that only one or two specimens were to 

 be found in which it was attached. Mr. Day thought he 

 had one, which I now possess ; but I find that its supposed 

 great value now only consists in its being that identical spe- 

 cimen ; for, upon examining it particularly, I find it has 

 only the characters belonging to Iron Haematites, viz. that 

 of being soft enough to show the streak upon being 

 scratched, and which is red, whereas the Wood Tin should 

 not vary in the colour of the streak, if it can be scraped at 

 all ', also of becoming strongly magnetic when heated by 

 the blow-pipe upon charcoal, whereas Wood Tin scarcely 

 becomes magnetic, but is reduced to pure Tin. Klaproth 

 observes that this Ore contains more Tin than any other 

 Ore of the same Metal. It is found in Cornwall at St. Denis^ 

 St. Columb, Altemon, 8cc. Spec. Grav. 7"2,9. 

 Analysis by Klaproth : 



Tin 77*50 



Oxygen 21-50 



Silex 0-75 



Oxide of Iron . . . 0-20 



100-00 



