8i 
HALL 78. 
N0N=J1ETALLIC MINERALS USED IN CHEHICAL 
HANUFACTURE, AND FOR OTHER 
PURPOSES. 
Some of the substances included under this group have a 
direct use, such as sulphur, salt, nitre, glauber salt, and 
alum. Again these and others are used for chemical pur- 
poses, as salt in the manufacture of chlorine ; fluor-spar as a flux 
m metallurgical operations ; pyrites and nitre in the manufa- 
ture of sulphuric acid. 
Cases 1 and 2. — Different grades of domestic and Eng- 
lish salt. 
Case 3. — Gypsum for the manufacture of plaster of Paris. 
Cases 4 and 5. — Sulphur, crude and refined. 
Case 6. — Asbestos and associated rocks. 
Case 7. — Complete collection of various forms of asbestos 
and its application, presented by the H. W. Johns Manufacturing Co. 
Case 8. — Mica and its commercial uses. 
Case 9. — Magnesite ; natural carbonate of magnesia from 
California. 
Case lO. — Various natural and prepared salts. 
Case 11. — American salts. 
Case 12. — A miscellaneous collection: — phosphates from 
Florida ; sulphur from Greece ; natural and prepared salts from 
Germany. A large and particularly fine cube of rock salt from 
Russia deserves attention. 
Platforms; — Large specimens of salt, gypsum, apatite- 
phosphate of calcium — fluorite, and iron pyrite. 
