CHEMISTRY. 219 



alumina. No deposit has been found in this country, for the rea- 

 son that no search has been made for it. The proper place to 

 look for it would be in beds of clay iron ore and yellow iron 

 stone. The remarkable thing about it is the entire absence of 

 silica, so that it does not resemble kaolin or potter's clay. It ap- 

 pears to bear about the same relation to kaolin that the hydrated 

 oxide of magnesia (brucite) does to serpentine, if we omit all 

 mention of the iron and other impurities. 



Bauxite has numerous applications in the arts. It is employed 

 in the manufacture of aluminium. The oxide of alumina behaves 

 like an acid, and will expel many acids at a white heat, without 

 itself being decomposed. It forms a soluble compound with 

 barytes, by which the alumina can be separated from iron. 



By fusing bauxite with soda ash the aluminate of soda is pro- 

 duced, an article of commerce which finds extensive application 

 in calico printing, and which could be employed in making glass 

 and ultra-marine. 



It is proposed to fuse bauxite with common salt, as one step in 

 a new process for the preparation of soda ash. 



Chile saltpetre, or nitrate of soda, is decomposed by bauxite, 

 nitric acid being expelled, and aluminate of soda resulting from 

 the fusion. 



Doubtless, by fusing common salt, nitrate of soda and bauxite, 

 soda, aluminate of soda, chlorine gas and nitric acid would be 

 produced, and if the aluminate of soda were to be decomposed by 

 carbonic acid, the alumina could be employed a second time. The 

 extensive manufactures in Newcastle now prepare 60 tons of sul- 

 phate of alumina every month from bauxite. They also manufac- 

 ture aluminate of soda, lime, and baryta and sulphite of alumina. 

 The latter salt is extensively employed in the manufacture of beet 

 sugar. Bauxite will find application as a substitute for alum, and 

 it can be employed for the decomposition of chloride of potassium 

 in working up kelp and the residues from salt works. It is also 

 proposed to use it for the decomposition of barytes. 



Very few minerals of recent discovery have attracted so much 

 attention, and it is to be hoped that deposits of it will be discov- 

 ered, in the United States. 



GYPSUM IN NOVA. SCOTIA. 



At the November meeting of the Nova Scotian Institute of Natu- 

 ral Science, Dr. How presented a paper, in which it was stated 

 that both gypsum and anhydrite are found in Nova Scotia in 

 quantitj', exclusively in the carboniferous rocks, in close associa- 

 tion with the sedimentary limestones. Gypsum has also been 

 found in small amount, in the fibrous form, in the trap rocks of 

 Blomidon, and as selenite, imbedded in the same rocks at Two 

 Islands. The local term for gypsum is soft plaster, for anhydrite, 

 hard plaster. The former is sulphate of lime with water; the 

 latter, sulphate of lime without water. 



The county of Hants is the chief gypsum raising county in Nova 

 Scotia, and Windsor the principal port of shipment. Operations 



