( 1755 ) 
nimis vel minimc nos craftino afficiunt die. Immo ad 
banc omnem diverfitatem operantur Temperie folummo- 
do difTerentibiis. 
Quum igirur tarn invidta fit ubiq^ difEculcas in debita 
Pharmacorum evacuantium dofe deccrnendas optandam 
ellet, methodus qua polfimus eadem abfqs dubio admi- 
niftrare. 
Methodum hartc apodeifticis expediit argurtientis, fimul 
& figillis occlufam prsefidi noftro commifit. 
Rogat tamen Medicos quoflibet, quoenam (it ilia vel 
fimilis Methodus qua fine errore dirigamur 5 eorumque 
folutiones adCalMart. 1705-6 exportabit, quas poftmo- 
dum cum fua publicabit. 
VIII. ^art of a Letter from Dr David Krieg, F. % S. 
Jo the^ubl 'tfher^ loncerning Cobalt^ and the prepara- 
tions of Smalt and Arfenic. 
I Spent about 8 weeks in my own Country, and my 
chiefeft BuGnefs was to enquire for the Minerals found 
thereabout, and to obferve their preparations.. Firft, I 
fhall defcribe the preparation of the blue Colour^ called 
Smaltum^Vf^iiichy^ made of Cobalt or CadMiafiMtiva^hecsLuCt it 
is not clearly dcfcribed by any Author, as much as I know. 
Now the Cadma or Cobalt is a maffie, heavy, grey 
ftiining Stone, found in a great quantity in the Mines 
about Shneeberg^znA fome other places of Htrmanduria. It 
is very often mixed with Marcafite, fometimes with 
Silver and Copper Oar, yea, the Silver is (butfeldom) 
pure in the Figure of Hair. 
After they have pick'd out the C^i^^/^ and feparated ft 
from the common Stone, they beat it to Powder by an 
Engine or Machine, commonly ufed in Mines (called a 
PooUvorL*)*' By that Operation, the Water carries away 
the light ftuff and Sand^ leaving the heavieft behind. 
• This 
