41 M»I N ERALOGIC Air 
amongft this we may feek for, and expedt 
to meet with, wood-tin. 
This rare tin-ore, which is entirely 
without the cryftallized form proper to 
tin-ores, and on the contrary refembles 
very much haematites, is not, as it at firft 
appears, a true haematites, with which 
fome tin is mixed, but a true and rich 
tin-ore, in which the portion of iron 
common to all tin-ores is only in an in- 
confiderable quantity, as will be feen 
plainly in the chemical analytes to be 
mentioned afterwards. 
Profeffor Brunnich, of Copenhagen, is, 
as far as I know, the firft who made this 
mineral known, and I fhall copy there¬ 
fore his words from a diflertation inferted 
in the Memoirs of the Royal Swedifh 
Academy of Sciences for the year 1778, 
under the title of A Defcripiion of two 
tin-ores from Cornwall. <i The other fpe- 
cies is very rarely found, and is called in 
Cornwall Woodlike tin-ore. It has fine 
fibres, converging to different centres, 
like 
