COMPOUNDS OF POTASSIUM AND SODIUM. 227 



Genesee Falls, near Rochester, N. Y. It is also obtained in 

 Austria, Hungary, and elsewhere in Europe. 



The artificial salt was first discovered by a German 

 chemist by the name of Glauber. 



AplitMtalitc (Arcanite). Potassium sulphate, K 2 4 S = Sulphate tri. 

 oxide 45 9, potash 54" 1 = 1 00. Found at Vesuvius. Misenite is a hy- 

 drous potassium sulphate from a cavern near Misene. 



Thenardite . Sodium sulphate Na <2 4 S= Sulphur trioxide 43 7, 

 soda 56 '3=100. From Spain, Bolivia, Tarapaca, in Peru; Slate Range, 

 San Bernardino Co., California ; and in Nevada. 



Glauberite. Sodium-calcium sulphate. In monoclinic crystals, at 

 Villa Ruhia, in New Castile, Aussee, in Austria, and other salt beds. 



Polyhalite and Picromeride are hydrous magnesium-potassium sul- 

 phates ; Blcedite and Loweite hydrous magnesium-sodium sulphates ; 

 Syngenite, a hydrous calcium-potassium sulphate. 



Borax. — Hydrous Sodium Biborate. Tinkal. 



Monoclinic. In oblique rhombic prisms I A 7=87°. Cleav- 

 age parallel with i-i perfect. The crystals are white and 

 transparent, with a glassy lustre. H. =2-2*5. G. =1*716. 

 Taste sweetish-alkaline. 



Composition. Na 2 O 7 B 4 + 10aq= Boron trioxide 30 6, soda 

 16 # 2, water 47*2 = 100. B.B. swells up to many times its 

 bulk and becomes opaque white, and finally fuses to a 

 glassy globule. 



Obs. Borax was originally brought from a salt lake in 

 Thibet, where it is dug in considerable masses from the 

 edges and shallow parts of the lakes. The holes thus made 

 in a short time become filled again with borax. The crude 

 borax was formerly sent to Europe under the name of tin- 

 kal, and there purified for the arts. It has also been found 

 in Peru and Ceylon. It has been extensively made from the 

 boracic acid of the Tuscan lagoons by the reaction of this 

 acid on sodium carbonate. 



Borax occurs under like circumstances in California and 

 Nevada, or is manufactured from other borates in solution 

 or in the solid state. Localities in California are Borax 

 Lake and its vicinity, north of San Francisco ; also near 

 "Walker's Pass, Sierra Nevada ; at Mono and Owens Lakes, 

 and at Death Valley, near the borders of Nevada ; in 

 the Slate Range, in San Bernardino County ; and in 

 Nevada, at Little Salt Lake, near Ragtown, on the Pacific 

 Railroad, and at Columbus Marsh. The Columbus Marsh, 

 in Nevada, near hit. 38° 5' N. and long. 118° W., 46 miles 



