Gt 
TASTE AND ODOR. 1 
4, Alraline—taste of soda. 
5. Cooling—taste of saltpetre. 
6. Litter—taste of epsom salts. 
7. Sour—taste of sulphuric acid. 
Odor is not given off by minerals in the dry, unchanged 
state, except in the case of a few gases and soluble minerals. 
By friction, moistening with the breath, the action of acids and 
the blowpipe, odors are sometimes obtained, which are thus 
designated : 
1. Alliaceous—the odor of garlic. It is the odor of burning 
arsenic, and js obtained by friction, and more distinctly by 
means of the blowpipe, from several arsenical ores. 
2. Horse-radish odor—the odor of decaying horse-radish. It 
is the odor of burning selenium, and is strongly perceived when 
ores of this metal are heated before the blowpipe. 
3. Sulphureous—odor of burning sulphur: Friction will 
elicit this odor from pyrites, and heat from many sulphides. 
4. Letid—the odor of rotten eggs or sulphuretted hydrogen. 
Tt is elicited by friction from some varieties of quartz and lime- 
stone. 
5. Argillaceous—the odor of moistened clay. It is given off 
by serpentine and some allied minerals when breathed upon. 
Others, as pyrargillite, afford it when heated. 

