196 Mr. Vivian on the Process of Amalgamation [March, 



is, therefore, an obtuse rhomboid of 92° 30'. The hardness is 

 sensibly greater than that of fluate of Ume. When pounded, the 

 colour is of a greenish-grey. The matrix seems to be the same 

 substance in an amorphous state with veins of fibrous hematite ; 

 it comes from Hohrhausen, on the Rhine. 



1 am also indebted to Dr. Wollaston for the chemical exami- 

 nation of this mineral, the result of which is very interesting, the 

 only substances he has been able to detect in it being oxide of 

 lead and oxide of iron. 



Article X. 



Description of the Process of Amalgamation as earned on in 

 German^/. Extracted from a Letter to John Taylor, Esq. 

 from John Henry Vivian, Esq. 



After some prefatory observations, Mr. Vivian proceeds to 

 describe the Freyberg processes, which are stated to be thus 

 conducted. 



The silver is extracted from the ores of the mining districts of 

 Saxony, partly by amalgamation, and partly by smelting ; or, to 

 make use of technical terms, some ores are treated in the 7vet, 

 and some in the clrij way. There are two works for smelting, 

 and one for amalgaination, in the neighbourhood of Freyberg, 

 •which is the capital of the mining districts of Saxony. I shall 

 confine myself, in the present paper, to the consideration of the 

 processes carried on in the latter. 



The Amalgamation-work is situated in a valley, near the 

 village of Halsbriicke, at a distance of about two miles from the 

 town of Freyberg, on the small river Mulda. I may here 

 observe, that in selecting a site for a work of this description, 

 regard must be had not merely to the proximity of the mines 

 from which the ore is to be obtained, but to the supply of 

 water, which should be constant, and in sufficient quantity for 

 all purposes for which it may be required. With respect to the 

 arrangement of the interior, the work at Freyberg may safely be 

 taken as a model, or at all events a description of it will afford 

 many useful hints in forming a similar establishment. Every 

 thing is done with a view to save manual labour, and to prevent 

 a loss of ore or metal in their removal from one place to the 

 other, or pilfering on the part of the men. At the close of ray 

 remarks, after describing the processes, I shall revert to this 

 part of the subject, which will be then the more readily under- 

 stood. 



The processes in an amalgamation-work are grounded on 

 chemical principles. From this circumstance, and from the 

 order and method that pervaded every part of the Freyberg esta- 



