Taufdlk^, a new Melal.-^Silver and Iron. ' 95 



pole, foliowitig the right fide of Serpentarius and the oppo- 



ihe fide of Hi.rculcs. Il was near enough to be obferved by 



the naked eye. 



On the ad of September C. Mechain tranfmitted to the 



Inftitiite a report on this comet. The elements he affigncd 



to it were as follow: 



Mean time - - - - g^ 24.' 6'*- 

 Right afcenfion - - - 249° 18 

 South declination - - 6 it' 'g¥« 



TANTAJLITE — A NEW METAL. 



A new metallic fubftance has lately been difcovered in 

 Sweden. It was extracted by the celebrated chemift Ekeberg 

 from a mineral given to him by M. Geyer. This mineral, 

 found in Finland, had been claffed among the ores of tin. 

 M. EdelcrantZj of the Academy of Stockholm, tranfmitted 

 a fpecimen of it to Delametheric, v/ho gives the following 

 dcfcription of it. It has a blackiili colour, with the metallic 

 afpe<Sl of ctvftals of oxidated tin. Its colour is equally 

 dark ; its gravity is confiderablc ; it ftrongly fcralches glafs. 

 Several facets arc dlftinguiihed in it, but the cryftal is in- 

 complete. M. Ekeberg has exi;ra<Sted from this mineral a 

 new metallic fubltance, to which he gives the name of I'att" 

 tal'iie. It forms the twenty-third mclalHc fubllance. 



SILVEK A^-D IRON. 



C. Gruyton announced, 25 years ago, that iron and filver 

 bTou<iht together into perfetit fufion fijrmed two feparate but- 

 tons adhering by their furfaccs. lie thought he could thence 

 conclude, contrary to the opinion of Gellcrt, that thefe tvvo 

 metals cannot be alloyed. 



Tlie ingenious experiments of Coulomb on magnetinn 

 havincr rendered it neceilarv for that philoiopher lo procure 

 metals warranted free from iron, C. Giiyton piopofcd to hiui 

 tn try a Initton of filver from which it appeared that nature 

 itfelf had feparatcd the iron. 



The filver, indeed, did fiot contain aqnantity of iron which- 

 could be rendered Icnfible by chemical re-agent{i, fuica a ioJ 

 lution of it did not give an atom of blue vvitli prulfiateof Ibda. 

 A portion of the fame fragment cxtrcil'cd a feniible action on 

 the magnetic bar; and Coulomb, having fubjecited it to his 

 magnetic apparatus,- ibuud thiii it ct*iilaincd a thirtieth ot 

 iron. 



It then became of importance to examine whether iron did 



not contain u certain quantity of filver. This C, Guyton did 



with his ufqal ubility. lie aliiircd liiuifelf th.U in iion ihtTc 



11 is 



