CHEMISTRY. 



81 



Nitrate*. 



Sp. 5. Sulphite of Ammonia-and-Magnesia. This 

 salt crystallizes, and is less soluble in water than ei- 

 ther of its constituents. 



Sp. 6. Sulphite of Lime. This salt is in the state 

 of a white powder, or if an excess of acid be added,. 

 it crystallizes in six-sided prisms, terminated by six- 

 sided pyramids. It has little taste, dissolves in about 

 800 parts of water, and in the air effloresces very 

 lowly, its surface being changed into sulphate. 



Sp. 7. Sulphate of Barytes. This salt, like the 

 preceding, may be obtained in crystals, by adding an 

 excess of acid. It crystallizes in needles. It is taste- 

 less, and nearly insoluble in water. 



Sp. 8. Sulphite of Alumina. This salt does not 

 crystallize. It is a white soft powder, with an earthy 

 and sulphureous taste. It is insoluble in water, 

 and when exposed to the air, it is slowly converted 

 into sulphate. 



The following Table exhibits the constituents of 

 the sulphites, as far as they have been ascertained. 



GENUS IX. Nilratet. 



All the salts belonging to this genus are soluble in 

 water, and crystallize by cooling. When heated to 

 redness, and charcoal powder thrown over them, a 

 violent combustion is produced. Sulphuric acid dis- 

 engages from them fumes of nitric acid. When heat- 

 ed, they are decomposed, and yield at first oxygen 

 gas. 



Sp. 1. Nitrate of Potash, or Nitre. This salt, 

 which is of great importance, is found in warm cli- 

 mates, on the surface of the earth. It is collected 

 and purified by solution and crystallization. Its 

 crystals are six-sided prisms, terminated by six-sided 

 pyramids. Its taste is sharp, bitterish, and cooling. 

 It is very brittle. It dissolves in seven parts of cold 

 water, and in leu than its own weight of boiling wa- 

 ter. Pure alcohol does not dissolve it. In a red heat 

 it melts and congeals into an opake mass, which has 

 been called mineral crystal. When kept melted, it 

 gives out about the third of its weight of oxygen gas. 

 It detonates most violently with charcoal. This salt 

 constitutes the principal ingredient of gunpowder, 

 which is a mixture of about 76 parts nitre, fifteen 

 charcoal, and nine sulphur. The constituents are 

 ground to a fine powder, and then mixed together 

 with great care. The goodncs* of the powder de- 



VOL. VI. PART I. 



pends upon the intimate mixture. Those kinds of 

 charcoal are pitched upon which absurb the least 

 moisture from the air. 



Sp. 2. Nitrate of Soda. This salt crystallizes in 

 transparent rhombs, differing but little from cubes. 

 It has a cool sharp taste, and is rather more bitter 

 than nitre. It dissolves in three parts of cold water, 

 and in less than its weight of boiling water. When 

 exposed to the air, it rather attracts moisture. Its 

 phenomena with combustibles and heat arc the same 

 as those of the preceding species. 



Sp. 3. Nitrate of Ammonia. This salt crystalli- 

 zes in six-sided prisms, terminated by six-sided pyra- 

 mids. It has a very acrid, bitter, disagreeable taste. 

 It dissolves in twice its weight of cold water, and in 

 half its weight of boiling water. In the air it very 

 speedily deliquesces. When heated, it undergoes the 

 watery fusion ; but even after the water is driven off, 

 it continues liquid at the temperature of about 400, 

 boils, and is decomposed, being converted into water 

 and nitrous oxide gas, in the proportion of about four 

 parts gas to three parts water. When heated nearly 

 to redness, it burns with a kind of explosion. Hence 

 it was formerly called nitnimjiamniaiu, 



Sp. 4. Nitrate of Magnesia. This salt crystalli- 

 zes in rhomboidal prisms, or small needle?. Its taste 

 is very bitter and disagreeable. It is soluble in little 

 more than its weight of cold water. In the air it 

 deliquesces. When heated, it undergoes the watery 

 fusion, and speedily assumes the form of a white pow- 

 der. It scarcely detonates with combustible bodies. 



Sp. 5. Nitrate of Lime. This salt crystallizes in 

 six-sided prisms, terminated by long pyramids. Ita 

 taste is very acrid and bitten It dissolves in about 

 the fourth part of its weight of cold water, and boil- 

 ing water dissolves-any quantity of it whatever. Boil- 

 ing alcohol dissolves its own weight of it. It speedily 

 deliquesces in the air. When heated, it readily un- 

 dergoes the watery fusion. When deprived of iti 

 water of crystallization, it often has the property of 

 shining in the dark. In this state it is called Bald- 

 inn's phosphorus. 



Sp. 6. Nitrate of Barylet. This salt crystallize* 

 in regular octahedrons, or in small brilliant plates. 

 Its taste is hot, acrid, and austere. It is soluble in 

 about twelve parts of cold water. When thrown up- 

 on burning coals, it decrepitates, and is converted in- 

 to a dry mass. When strongly heated, the whole of 

 its acid is dissipated, and pure barytes obtained. 



Sp. 7- Nitrate of Strontian, This salt crystalli- 

 zes in regular octahedrons, not unlike the crystals of 

 nitrate of barytes. It has a strong, pungent, cool- 

 ing taste. It is soluble in its own weight of cold 

 water, and in little more than half its weight of boil- 

 ing water. It is insoluble in alcohol. It deflagrate* 

 on hot coals. In a crucible it melts when heated. 

 At a red heat it gives out its acid, and pure stron- 

 tian remains behind. Combustible* thrown into it 

 when red hot, burn with a lively red flame. 



Sp. 8. Nitrate of Ammonia-and-magnesia. This 

 salt crystallizes in fine prisms. It has a bitter, acrid, 

 ammoniacal taste. It dissolves in about eleven parrt 

 of cold water. In the air it gradually attracts mois- 

 ture, and deliquesces. 



Sp. 9. Nitrate of Alumina. This salt crystallite* 



E!emem 



of 

 Chemistry, 



