92 Maine; agricultural Experiment station. 19 12. 



Preparing spirit of nitrous ether. This may be prepared 

 according to the U. S. P. Eighth Edition or may be made from 

 concentrated nitrous ether. 



If the latter method is used, follow directions for preparation 

 as given by the manufacturer as regards the proportions of 

 concentrated nitrous ether and alcohol to be used. 



Thoroughly chill both the concentrated nitrous ether and 

 the alcohol. Use a towel or other non-conducting material in 

 handling the concentrated nitrous ether container. Do not pour 

 through the air more than absolutely necessary. 



Keeping spirit of nitrous ether. Store in small, amber colored, 

 glass bottle, stoppered with tight fitting cork stopper. Do not 

 use a ground glass stopper. 



Keep the bottle in a cool place. Room temperature is not cool 

 enough. 



Put the date of manufacture on the bottle. 



Do not sell after six weeks from preparation without testing 

 strength by assay. If weak bring up to strength by adding con- 

 centrated nitrous ether q. s. and put new date on bottle. 



Put date of manufacture on bottle given to customer. 



A cautionary statement on the label of the dispensing bottie 

 advising the customer of the volatile nature of sweet spirit of 

 nitre and that it should be kept tightly stoppered in a cool ]'>iace 

 and not used more than 12 weeks after date of manufacture 

 is .advised. 



SaxViples Collected in Winter oe 1912. 



Although the experiment . on keeping spirit of nitrous 

 ether given above was made in hot weather, the collecting of 

 samples was made 'in cold weather when it is possible to keep 

 preparations cold without the use of a refrigerator. As spirit 

 of nitrous ether will not freeze at any natural temperature it 

 may be kept in Maine far below the freezing point much of 

 the time. When the present samples were for the most part 

 collected the average temperature for weeks had been -1.5° 

 below zero Eahrenheit. 



The results of the examination of the samples purchased 

 from druggists are given in the table which follows. 



