_ WATER. 231 
It is a valuable article In medicine, and is employed by 
tinmen in soldering to prevent the oxidation of copper sur- 
faces ; also in a variety of metallurgical operations. 
Mascagnite. A hydrous ammonium sulphate. In mealy crusts, 
of a yellowish-gray or lemon-yellow color ; translucent ; taste pungent 
and bitter. Composition (N H,)20,S+H,O=Sulphur trioxide 53:3, 
ammonia 22°8, water 23°9. Easily soluble in water. Occurs at Etna, 
Vesuvius, and the Lipari Islands. It is one of the products from the 
combustion of anthracite coal. 
Lecontite is hydrous ammonium-sodium sulphate. Bowssingauiltit 
is a hydrous ammonium-magnesium sulphate, from Tuscany. ; 
Struvite. A hydrous ammonium-magnesium phosphate ; occurring 
in yellowish crystals, slightly soluble in water; found on the site 
of an old church in Hamburg, where there had been quantities of cat- 
tle dung. 
Tschermigitec. An ammonia alum from Tschermig, Bohemia, and 
Utah County, Utah 
Larderellite. A white tasteless ammonium borate, from the Tuscan 
Jagoons. 
Hydrous ammonium phosphite and Anvmonium bicarbonate (Tesche- 
macheritc) have been detected in guano; also, Hydrous sodium-am- 
monium phosphate, called Stercorite. 
HYDROGEN. 
Hydrogen is the basic constituent in hydrochloric acid, 
and in water. 
Eiydrochloric Acid.—Muriatic Acid. 
A gas, consisting of Chlorine 97:26, hydrogen 2°74=100 
=HCl. It-has a pungent odor, and is acrid to the skin. 
It is rapidly dissolved by water. If passed into a solution 
of nitrate of silver, it produces a white precipitate which 
soon blackens on exposure. It is given out whenever com- 
mon salt is acted on by sulphuric acid, and occasionally by 
volcanoes. 
WATER. 
Water (hydrogen oxide) is the well-known liquid of 
streams and wells. The purest natural water is obtained by 
melting snow, or recciving rain ina clean glass vessel ; but it 
is absolutely pure only when procured by distillation. It 
consists of hydrogen 1 part by weight, and oxygen 8 parts, 
or hydrogen 11°11, oxygen 88°39=100. It becomes solid at 
32° Fahrenheit (or 0° Centigrade), and then crystallizes, 
and constitutes ice or snow. The crystals are of the hex- 
agonal system. I*lakes of snow consist of a congeries of 
