NATURAL HISTORY of N RWAT. 



through wears from one refervoir into another, till it has attained 

 its proper pungency. The falt-pans, or the large kettles in which 

 the water is boiled, yields in two or three days two and twenty tuns 

 of fait, large meafure, the tun being computed at twelve bufhels, 

 and each pan requires every time four or five fathoms of wood. 

 But in fpfing, or the beginning of the fummer, where, by the 

 melting of the fnows, the rivers carry a greater quantity of frefh- 

 water into the fea, which fomewhat diminifhes its faltnefs, the 

 boiling requires longer time, and confequently more wood. Mr. 

 Miiller accounts this fait better than that of Lunenburgal, tho' 

 fome, poflibly from conceit or partiality, affert the contrary. This 

 fait- work has a feparate jurifdi&ion, from which, however, an ap- 

 peal lies to the minery-court at Kongfberg. 



It was imagined that arfenic had been found in the lilver- 

 mines of Jarlfberg, and to this, among other things, the hardnefs 

 of the ore was attributed, but perfons better verfed in thefe mat- 

 ters, deny any fuch thing. 



SECT. XVIII, 



vitriol. Vitriol, the infeparable concomitant of copper and iron, might 



be had here in great plenty if the preparation of it could be 

 brought to turn to good account. The Norway-company, fome 

 years ago, begun to eftablifh, jiear Kongfberg, a vitriol- work, 

 which they called the Loft-Sons ; but that, antecedently to this, 

 there had been vitriol- works in Norway, appears from the follow- 

 inMuf.cap. ing words of Ol. Wormius: " In Norvegia fimile vitriolum ela- 

 boratur arte, magis ad caeruleum quam ad viridem tendens colo- 

 rem, verum non in mailis, fed in granulis afperis et inaequalibus 

 proftat. Viribus et facultatibus nulli cedit." The Englifh prepare 

 their vitriol from a kind of yellow-veined pyrites, which, after 

 being expofed three months to the open air, becomes fit for yield- 

 ing vitriol. It is hardly a queftion, whether the like might not 

 alfo be done here ? 



SECT. XIX. 



Allum, which has fo near an affinity with the former, and con- 

 tains it, is found in great plenty under Egeberg, near Chrifliania, 

 betwixt the Hate-flakes, and works have alfo been fet up there, 

 which yield plenty of vitriol as well as Allum ; but the latter is 



not 



X. p. 2J. 



Allum. 



