100 ' SALTS OF AMMONIA. 



Tellurium and Osmium are other metals having chemical relations 

 to sulphur. They form similar compounds with the metals. They are 

 of rare occurrence. 



The minerals containing the elements arsenic, selenium, tellurium and 

 osmium, are described under Class VII, including metals and metallic 

 ores. 



CLASS V.— HALOID MINERALS. 



1. AMMONIA. 

 The salts of ammonia are more or less soluble, and are 

 entirely and easily dissipated in vapor before the blowpipe. 

 By this last character they are distinguished from other 

 salts. 



sal ammoniac. — Muriate of Ammonia. 



Occurs in white crusts or efflorescences, often 

 yellowish or gray. Crystallizes in regular 

 octahedrons. Translucent— opaque ; taste sa- 

 line and pungent. Soluble in three parts of 

 water. 



Composition : ammonium 33*7, chlorine 66*3. Gives off 

 the odor of hirtshorn when powdered and mixed with 

 quicklime. 



Dif. Distinguished by the odor given off when heated 

 ilong with quicklime. 



Obs. Occurs in many volcanic regions, as at Etna, 

 Vesuvius, and the Sandwich Islands, where it is a product 

 of volcanic action. Occasionally found about ignited coal 

 seams. 



But the sal ammoniac of commerce is manufactured 

 from animal matter or coal soot. It is generally formed in 

 chimneys of both wood and coal fires. In Egypt, whence 

 the greater part of this salt was formerly-obtained, the fires 

 of the peasantiy are made of the dung of camels , and the 

 soot which contains a considerable portion of the ammonia- 

 cal salt«is preserved and carried in bags to the works, where 

 it is obtained by sublimation. Bones and other animal mat- 

 ters are used in France, and a liquor condensed from the gas 

 works, in England. 



What are general characters of the salts of ammonia 1 What is a 

 distinctive character of sal ammoniac 1 What is its composition ? From 

 What is it ma lufac'ured 1 How is it manufactured in Egypt 1 



