j8o Academy at Erfurt, — Academy at SlocUohn. 



ELECTOBAL ACADEMY OF THE USEFUL SCIENCES 

 AT EKFURT. 



In the fitting of January 3d, Count Von Beuft read an 

 extraA from a treatife, written by his fon Frederick Auguftus 

 Leopold, Count Von Beuft, of the Academy of Mines at 

 Freyberg, on the amalgamation of filver ore as praftifed at 

 the Halfbruck and Ultermuld works near that place. From 

 this paj>er and the annexed tables, it appears that 79785 J cwt. 

 of ore, which, according to the common mode of amalga- 

 mation, would have given only 31139 pounds 4! ounces of 

 lilver, produced, by the method employed at Freyberg, 

 38330 pounds 3]- ounces ; confequently, there was a faving 

 of 1190 pounds 7|- ounces. 



Ill this treatife the author obfervcs, that the theory of amal- 

 gamation is much indebted to the important experiments of 

 the Spaniard Don Ethovar, who proved, contrary to the opi- 

 nion of feveral eminent chemifts, that the muriatic acid, in 

 a concentrated ftate, diflblves gold as well as filver when 

 thefe metals are reduced to fmall particles. 



Profeflbr Trommfdorf read a continuation of his colleftions 

 towards a chemical knowledge of mineral bodies. This part 

 related chiefly to fome precious ftones from India which he 

 had examined. 



ROYAL ACADEMY OF INSCRIPTIONS, THE FINE 

 ARTS, HISTORY, AND ANTiaUITIES, AT STOCK-p 

 HOLM. 



The Academy, in the fitting of April 9, propofcd the fol- 

 lowing prize fub)c6ts for the year 1800. 



Hijiory. — A hiftorico-critical dilfertation on the printed 

 or unprinted works which have been written by individuals 

 of the royal family of Sweden. The prize is a gold medal of 

 the value of twenty-fix ducats. 



Foreign Languoges. — What are the advantages or difad- 

 vantages jn regard to the general happinefs of mankind of 

 the prefent as compared with the laft century ? The prize is 

 a gold n"»edal of the fame value. 



Anti^uiiies, — Examination of the origin, nature, and obje6l 



of 



