454 DEUTOX1DE OF NITROGEN. 



(g.) Specific gravity ; air being 1. it is 1.041, and 100 cubic inches 

 at 60 Fahr. and 30 inches of the barometer weigh 31.770* grains ; 

 compared with hydrogen its weight is 15. 



4. COMPOSITION. 



(a.) Potassium, heated in this gas, abstracts 50 per cent, of oxy- 

 gen and leaves the same quantity of nitrogen; as 50 cubic inches of 

 oxygen weigh 16.944 grains, and 50 of nitrogen 14.826, its weight 

 is plainly, for 100 cubic inches, 31.770, as stated above. As there 

 is no condensation attending the union of the gases which unite in 

 equal volumes, we easily obtain the specific gravity by calculation ; 

 thus the specific gravity of oxygen gas, air being 1, is - 1.1111 

 that of nitrogen gas is .9722 - .9722 



The sum of which 2.0833 divided by 2 = 1.041. 

 By volume, therefore, this gas consists of 50 oxygen and 50 nitro- 

 gen; by weight of 53.4 oxygen and 46.6 nitrogen; the difference 

 between the number expressing the weight and the volume is owing 

 to the difference in the specific gravity of the two gases. 



(b.) Heat, applied in porcelain tubes, and electric sparks decom- 

 pose this gas ; the product resembles common air, and a portion of 

 the original gas is left undecomposed. 



(c.) Iron, zinc, tin, arsenic, phosphorus, charcoal and the alkaline 

 sulphurets, by abstracting oxygen, convert it either into nitrous oxide 

 or nitrogen. 



5. CONSTITUTION. The equivalent number of this gas is obtain- 

 ed by adding 14, which is the number for nitrogen, to 16, which 

 represents two equivalents of oxygen, and 30 therefore represents the 

 nitric oxide. 



6. PROPERTIES. 



(a.) Invisible, colorless, and permanently elastic. 



(b.) Not much absorbed by water, unless previously boiled, when 

 it takes up, by agitation, about T V of its bulk, which is again expelled 

 by ebullition. f Dr. Turner states the absorption at 1 or about 11 

 per cent. J 



(c.) Very hostile to life; warm blooded animals, immersed in it, 

 are killed almost instantly, and it destroys the irritability of the heart. 

 It kills by suffocation and by excoriation. It becomes nitrous acid 



* Its weight was formerly stated by Sir H. Davy at 34.26 grains. 



t The impregnated water is said to generate nitrate of ammonia after long keep- 

 ing ; this is perhaps not extraordinary, as all the elements are present, namely, hy- 

 drogen and oxygen in water, arid oxygen and nitrogen in the nitric oxide. 



1 Elements, p. 186. 



