ETHERS AND ESTERS. 523 



Ethyl nitrite, C 2 H,NO 2 = 74.51 (Nitrous ether). Can be made by 

 distilling a mixture of alcohol, sulphuric acid, and sodium nitrite : 

 C 2 H 5 OH + NaNOj + H 2 SO 4 = C 2 H 6 NO, + NaHSO< + H 2 O 



The distillate, which contains, besides ethyl nitrite, some alcohol 

 and often some decomposition products, is washed with ice-cold water, 

 in which ethyl nitrite is nearly insoluble, and with sodium carbonate 

 to remove traces of acid ; finally, it is freed from water by treatment 

 with anhydrous potassium carbonate. It boils at 17 C. (62.6 F.). 



The process adopted by the Pharmacopoeia differs from the former by 

 dispensing with the distillation and using the insolubility of the ether 

 in ice-cold salt solution for its separation. The process is carried out by 

 pouring a cold solution of sodium nitrite very slowly into an ice-cold 

 mixture of sulphuric acid, alcohol, and water. Decomposition takes 

 place as in the reaction given above. Some sodium-acid sulphate is 

 precipitated and has to be separated from the liquid, which is poured 

 into a separating funnel where two layers form. The lower aqueous 

 solution is drawn off and the remaining nitrous ether is purified like 

 the distillate obtained in the first process. (For assay-method of ethyl 

 nitrite, see paragraph on gas-analysis.) 



Spirit of nitrous ether, Spiritus cetheris nitrosi, Sweet spirit of niter. 

 This is a mixture of about 4 parts of ethyl nitrite with 96 parts 

 of alcohol. It is a clear, mobile, volatile, and inflammable liquid, of 

 a pale straw color inclining slightly to green, a fragrant, ethereal 

 odor, and a sharp, burning taste. It is neutral, or but very slightly 

 acid to litmus paper but evolves no carbon dioxide with potassium 

 bicarbonate. 



Amyl nitrite, Amylis nitris, C 5 H U NO 2 = 116.24. Made by a 

 process analogous to the first one mentioned above for ethyl nitrite, 

 substituting amyl alcohol for ethyl alcohol. 



The official amyl nitrite contains of this ether about 80 per cent., 

 together with variable quantities of undetermined compounds ; it is 

 a clear, pale-yellowish liquid, of an ethereal, fruity odor, an aromatic 

 taste, and a neutral or slightly acid reaction. Specific gravity 0.865. 

 Boiling-point 96 C. (205 F.). The low boiling-point necessitates 

 special precautions in storing the article. It is best kept in sealed 

 vials and dispensed in sealed glass bulbs, each containing only a few 

 drops of the liquid. 



Fats and fat oils. All true fats are esters of the triatomic alcohol 

 glycerin, in which the three replaceable hydrogen atoms of the hy- 



