90 Maine; agricuIvTuraIv eixpiiRiment station. 1912. 



SPIRIT OF NITROUS ETHER. 

 (Sweet spirit of nitre) 

 There is probably no preparation dispensed by druggists that 

 is more liable to deterioration than sweet spirit of nitre. The 

 U. S. Pharmacopoeia Eighth Revision gives a method of prep- 

 aration that will in the hands of an experienced pharmacist 

 give a uniform and satisfactory preparation. It is doubtful if 

 any pharmacist in Maine prepares spirit of nitrous ether in this 

 way, but makes it instead by diluting concentrated nitrous 

 ether purchased from manufacturing druggists and chemists. 



CONClJNTRATED NiTROUS Eth^R. 



Frequent examination of the concentrated nitrous ether used 

 by Maine druggists has been made and in no instance has the 

 resultant preparation made by the Station chemists been below 

 the standard given in the Pharmacopoeia. The only criticism 

 that can be made is that the concentrated nitrous ether sent out 

 by one house made, in the two times it was tested at the Station, 

 a preparation that was a fifth over strength. Part of the over- 

 strength reported in the table on pages 93 and 94 was due to 

 the use of this company's concentrated nitrous ether. 



Concentrated nitrous ether usually remains in perfect condi- 

 tion for many months if the containers are kept hermetically 

 sealed. As soon as the concentrated nitrous ether is opened, 

 even in the cold, loss from evaporation commences. The manu- 

 facturers are now putting dates upon their concentrated nitrous 

 ether packages and the length of time they are guaranteed to 

 retain their strength. 



How Long Wii,Iv Spirit of Nitrous Ethe;r Ke;e;p Standard? 

 In order to test this point one of the Station chemists made 

 up from a Smith, Kline & French Company's tube of concen- 

 trated nitrous ether about one pint of sweet spirit of nitre. 

 Care was taken to follow exactly the directions upon the tube. 

 As soon as prepared this was analyzed and found to carry 4.06 

 per cent ethyl nitrate or equal to 101.5 per cent U. S. P. stand- 

 ard. This was stored in an amber bottle, stoppered with a cork 



