Iron. 279 



and is fcarcely foluble in acids* Hiftor.ferri* 

 P- 733- 



II. VARIETY. 

 Sivampey Argillaceous Ores* 



Mnera ferri Lacuftris ve! fubaquofa. Mine 

 defer Limoneuse. 



23. When dry, this ore is friable, and 

 brown, or brownifh black, and appears either 

 in Jumps of an irregular fhape, or in round 

 balls porous or folid, or in flat round pieces, 

 or in grains, and fometimes in (lender trian- 

 gular prifms parallel to each other, and very 

 brittle. It is mixed with argill and ex- 

 tractive matter, and becomes magnetic after 

 calcination, by which operation it lofes about 

 J of its weight, and the greater part of what, 

 is thus volatilized is water, the remainder 

 aerial acid and volatil alkali. The crude ore 

 affords about 36 per cent, of regnlus, and 

 after calcination about 50 per cent, it is the 

 chief matrix of fiderite, and the iron pro- 

 cured from it is coldfhort^ at leaft in Sweden. 

 The iron of Hufaby^ of which Mr. Bergman 

 treats in his analyfis of iron, is drawn from 

 this ore. Mr. Hielm has found fome forts of 

 it to contain 28 per cent, of manganefe. 



T 4 SPECIE 



