458 HYPO-NITROUS ACID. 



nitrous oxide (protoxide) will be left, the remainder having com- 

 bined with the alkali in the form of hypo-nitrous acid, oxygen having 

 been afforded by one portion of the nitric oxide, which was thus re- 

 duced to nitrous oxide, while the other, by the aid of the oxygen, 

 became nitrous acid. 



(c.) Gay-Lussac supposes that he obtained the same acid by dis- 

 tilling the nitrate of lead, the volatile product being condensed in a 

 receiver, kept cold by a freezing mixture.* But it is perhaps, not 

 certain that the hypo-nitrons acid has yet been obtained in a state of 

 freedom. 



3. PROPERTIES. 



(a.) The acid obtained by Gay-Lussac, from the destructive dis- 

 tillation of nitrate of lead, boiled at 79 Fahr. and was dissipated in 

 very dense red fumes. 



(6.) Poured into water, nitric oxide gas ivas abundantly liberated^ 

 " and the water became blue, green, and yellow, according to the 

 proportion added." 



(c.) Sulphuric acid, either strong, or a little weakened, and at a 

 moderate temperature, forms with the hypo-nitrous acid, four sided 

 prisms, which, as well as the fluid in which they are produced, emit 

 nitric oxide gas by the contact of water. 



(d.) Nitrous acid vapor, passed into sulphuric acid gives also a 

 similar compound.-^ 



4. CONSTITUTION. Hypo-nitrons acid appears to consist, by 

 measure, of 200 of nitrogen to 300 of oxygen, or of 100 to 150 ; 

 for since 100 measures of oxygen (see 2,) are mingled with 400 of 

 nitric oxide to produce hypo-nitrous acid, and as nitric oxide consists 

 of equal volumes of nitrogen and oxygen, it follows that the propor- 

 tions are as above stated. Also, in the experiment 2. (b.) " deduct- 

 ing from the nitrogen and oxygen originally contained in the nitric 

 oxide gas, the quantities constituting 25 of nitrous oxide, we shall 

 find that 25 volumes of nitrogen, and 37.5 of oxygen had disappear 

 ed and formed a new compound, which was absorbed by the potassa. 

 Thus 100 nitric oxide gas =50 nitrogen +50 oxygen, 



25 nitrous oxide gas =25 " -j-12.5 " 



25 37.5 



and 25 : 37.5 : 100 : 150." H. 



These are exactly the proportions assigned by Gay-Lussac to the 

 hypo-nitrous acid. 



* Dulong and Dr. Thomson, however, suppose that the acid obtained in this case 

 was the real nitrous. Murray. 



t Also by mingling oxygen gas, sulphurous acid, nitric oxide gas, and aqueous 

 vapor, a similar compound is produced. Clement and Desormes, its discoverers, 

 supposed it to consist of sulphuric acid and nitric oxide gas. H. 



