^7-* On the fifw Mtlal, TeUurttim, 



XV. ■ 



jlhJiraB of a Memoir of KlaPROTH, on a new Aletal cJet:om!iiatcd Tellurium. Rend at 

 tl>e Public Sejfion of the Academy of Sciences at Berlin, January the 2^th, 1798*. 



K, 



.LAPROTH, the chemift; of Berlin, in the chemical analyfis of the auriferous ore, 

 known by the name of the white ore of gold (weifs goklerz), aurum psradoxum, metalluni 

 vel aurum problematicum f, has difcovered in that mineral, a metal abfolutely diflerent 

 from all thofe which have hitherto been known, to whicii he has given the n^ime of Tel- 

 lurium, forming a kind of feries.or arrangement with the new metals difcovered by him 

 ■fome time ago, and denominated Uranium and Titanium. Mr. Muller of Reichenftein, 

 in the year 1782, had fufpedled the exiftence of a peculiar metallic fubflance in this mine- 

 •ral. Bergman, to whom he had forwarded a fpecimen of the ore, confirmed his fufpicion ; 

 ,but on account ofthe fmall quantity upon which he operated, he did not think fit to decide, 

 ■whether this fofiil did aiftually contain a new metal, or whether it might not be antimony 

 ^vhich he had miftaken for a new prot!u£i. The numerous and ingenious experiments to 

 which Klaproth has fubjefted a more confiderable quantity of this ore, which was fent to 

 iiim by Mr. Muller J, perfectly confirm the fufpicions of that chemift, and of Bergman. 



The Procefs for obtaining this Aletal from its Ore, 



1. A portion of the ore is gently heated, with fix parts of muriatic acid ; three parts of 

 nitric acid are then to be added, and the mixture fubjedled to ebullition. A very confider- 

 able effervefcence takes place, and the folution becomes complete- 



2. The .filtered folution is to be diluted with as much water as it can bear without becom- 

 ing turbid, which quantity is very little. A folution of cauftic pot-afh is then to be added, 

 until the white precipitate, which is at firft formed, (ball difappear, and nothing but a brown 

 depofition in flocks fhall remain. 



3. Thislaft precipitate is a mixture ofthe oxides of gold and of iron, which maybe fepa- 

 rated by the ufual methods. 



' 4. To the alkaline folution (2), muriatic acid muft be added, fufficient for the perfe£t 

 faturation of the alkali ; but not in excefs. A white and very abundant precipitate it 

 afforded, which, on the application of heat, falls to the bottom of the vefFel in the form 

 of a heavy powder. After wafliing and drying this precipitate, it is to be formed into a 

 kind of pafte, with a fufficient quantity of any fat oil ; and this mafs is introduced into a 

 fmall glafs retort, to which a receiver is loofely to be applied. In this difpofition of the 



• This abftraft was communicated on the part of the author, by M. Rofe, i chemift of Berlin, and was tranf- 

 jated and forwarded to the Phylomatic Society at Paris, by L. Hecht the younger. The French tranflation, 

 which of courfe I muft follow (a? the original is unpubliflied), is inferted in the xxvth vol. of the Annales de 

 Chimie, p. t73» 



.f. This mineral is found in the mine called Afar/nA/T^, in the Fatzbay maviMzxn^ nesx Zaletbna in Iraiifilvania. 

 Sec Emmerling's Elements of Mineralogy, II. 124. et feq. (orKirwan, II. 324. N.) 



+ In the origiBal the words are " M. de Reichenftein," which I fuppofe to be an overfight, and that I ara 

 ♦orreft in tranflating the words M. Muller de Reichenftein which occur a few lines before, on the fuppofuion that 

 '%/l, Muller aitually r«fides at Reichenftein, without deriving any titular name from that town. N. 



apparatus. 



