130 PROCEEDINGS OF SECTION B. — SUB-SECTION, PHARMACY. 



Solutions of ethyl nitrite lose strength in at least three different 

 ways — 



1st. — By evaporation. 



2ndi. — By spontaneous decomposition, probably as represented 

 by the following equation — 



2C2H5NO2 - CH3CHO + C2H5OH + 2N0. 

 3rd. — By hydrolysis and subsequent oxidation, possibly some- 

 what as follows : — 



(a) C2H5NO2 + 2H2O = 2C2H5OH + 2HNO2. 

 (&) C2H5OH + 2HNO2 = C2H4O + 2N0 + 2H2O. 

 (c) C2H4O + 2HNO2 - CH3COOH + 2N0 + H2O. 



It was, no doubt through recognising the efiects of hydrolysis in 

 spirit of nitrous ether that the compilers of the present British PTiarma- 

 copcBia introduced a solution in absolute alcohol and glycerin under 

 the name of liquor ethyl nitritis, but this preparation is rarely used. 



The rapidity of hydrolysis of ethyl nitrite is such that it is practi- 

 cally useless to prescribe it in an aqueous mixture ; it should be diluted 

 immediately before administering it. 



That the "liquor" keeps better than the "spirit" is shown by 

 the following rough gasometric analysis performed as described in the 

 British Pharmacopceia. The fact that corrections for barometric 

 pressure and vapour tension are not given does not detract from the 

 value of the figures as a comparison since the analysis were performed 

 side by side. 



Spirit of Nitrous Ether. 



Date. Temperature. Vol. of No. from 5 c.c. 



1911— 6th June .. 22-6'' C. 



14th December .. 34-0° C. 



1912— 30th April .. 22-0° C. 



31st May .. 20*5° C. 



Solutions of Ethyl Nitrite 



1911— 6th June .. 22-6° C. 



14th December .. 34*0° C. 



1912— 30th April .. 22*0 0. 



31st May .. 20-5° C. 



38-0 c.c. 

 28-5 c.c. 

 23-0 c.c. 

 20-4 c.c. 



38-4 c.c. 

 35-2 c.c. 

 34-0 c.c. 

 31 -Sec. 



These figures are picked from a series of monthly determinations, 

 but all are not stated as they might somewhat obscure the issue. 



Both samples were stored in accurately fitting glass-stoppered 

 bottles in a cupboard, and were only opened for the purposes of with- 

 drawing the necessary amount of solution for analysis. The colour 

 of the bottles was, under these circumstances, of no importance. 



