444 



FOODS AND FOOD ADULTERANTS. 



Dr. W. Ramsay of an apparatus used by him in the determination of 

 tbe molecular weights of nitrogen trioxide and nitric peroxide.* The 

 rise of temperature is not wholly independent of the initial tempera- 



Fio. 22. 



ture, and hence the initial temperature should be kept as nearly constant 

 as possible; since most lards and sjdnlterated lards melted at rather a 

 high temperature are still liquid at 35 this temperature becomes a 

 very convenient starting point. For oleo stearines the initial tempera- 

 ture should be 10 higher. 



DESCRIPTION OF APPARATUS. 



The test tube should be about 24 cm in length and 5cm in diameter. 

 It is furnished with a stopper with three holes, the one through the 

 center carrying a delicate thermometer graduated to at least fifths of a 

 degree. The second opening carries loosely a glass stirring-rod, which 

 is bent into a coil at the lower extremity. This coil is so arranged as to 

 have the thermometer pass through its center. The third perforation 

 carries the funnel, which is bent outwards and upwards and holds the 

 sulphuric acid. 



".Journal of t.lic Clu-iniral Society, .Iiinc, 1S-*H, page G22. Wlien in use tin- \\holo 

 lower part of the apparatus is inclosed in a nou-conductiujj case, as inrutioiied in 

 the text, 



