HALL 7Q. 
NON-HETALLIC MINERALS USED IN CHEillCAL 
riANUFACTURE, 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 m 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 En<^- 
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 ns 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 10.— 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 
Kussia deserves attention. 
Platforms ;-Large specimens of salt, gypsum, apatite- 
phosphate of calcium— fluorite, and iron pyrite. 
