NITRATE OF AMMONIA. 475 



(d.) The compact nitrate suffers no change below 260 ; from 275 

 to 300, it sublimes slowly, without suffering decomposition or becom- 

 ing fluid; at 320 it melts, and from 340 to 380, is decomposed 

 partly sublimed, and yields the above mentioned gas.* If the tem- 

 perature does not rise above 500, the salt is ivholly decomposed and 

 converted into nitrous oxide and water, in the proportion of about 3 

 parts of gas to 1 of water. 



100 grains of the salt afford 84 cubic inches of the gas. 



The hydrogen of the ammonia, ivith one proportion of the oxygen 

 of the nitric acid forms water ; the remainder of the oxygen and of 

 the nitrogen, forms the nitrous oxide gas. 



(e.) At 600 and above, this salt explodes by the reaction of its 

 own elements, being converted into nitrous acid, nitric oxide gas, wa- 

 ter and nitrogen gas. 



(/.) On red hot iron or any other ignited body, it deflagrates beauti- 

 fully with a rich yellow flame, and exhibits a singular instance of a 

 burning saline body ; the reaction of the oxygen of its acid with the 

 hydrogen of its base, produces the rapid combustion. Hence its 

 old name of nitrum ,flammans. 



4. USES. They are limited to the formation of nitrous oxide, 

 and to some cases in chemistry, when we wish, by heat, to oxidize 

 substances, and to have no residuum ; the nitrate of potassa always 

 leaves that alkali free or combined, but the nitrate of ammonia when 

 deflagrated, leaves nothing behind. 



5. ALKALIES AND EARTHS. Baryta, strontia, potassa, soda, and 

 lime, by trituration in the cold, attract the acid and liberate the am- 

 monia. 



6. EQUIVALENT NUMBER AND COMPOSITION. This salt is com- 

 posed of acid, 1 proportion, 54, ammonia, 17 = 71, for the dry salt, 

 and according to Berzelius, 1 proportion of water 9, for the prismatic 

 variety, =80. 



The proportions of Berzelius, are for the 100 parts acid, 67.625, 

 base, 21.143, water, 11.232 = 100.00f 



The composition according to Davy, is for the 

 Prismatic crystals, 69.5 Fibrous, 72.5 Compact, 74.5, acid. 



" " 18.4 " 19.3 " 19.8, ammonia. 



" " 12.1 " 8.2 " 5.7, water. 



100. 100. 100. 



* According to my experience, the compact nitrate, if not very carefully dried, 

 (which is difficult on account of the fluid imbibed by its pores,) is apt to puff up in. 

 the retort, with a violent effervescence of aqueous vapor ; while the dry prismatic 

 nitrate is perfectly manageable, and is decomposed with great steadiness and unifor- 

 mity. 



t Ann. de Chim. T. LXXX, p. 182. 



