96 CONTRIBUTION TO THE STUDY OF 



hydi-oxylaiiiine. The laethod followed was that of Divers and 

 Haga. To start with, 900 gms. of sodium nitrite and the corres- 

 ponding amount of sodium carbonate were taken. Tlie sulphur 

 dioxide was prepared by acting upon copper with sulphuric acid. 

 When this gas is passed into a mixed solution of sodium nitrite 

 and sodium carbonate a marked rise in temperature takes place. 

 To keep the solution cool, which is necessary in order to prevent 

 decomposition, the vessel containing it was surrounded b}^ ice and 

 salt. Further precautions were taken to prevent decomposition of 

 the solution by keeping it well stirred. The delivery tube was 

 made to act as a stirring rod. It cons'sted of a piece of glass tub- 

 ing shaped thus, 1 — the longer arm dipping into the liquid, 

 while the shorter was made to pass through a cork and con- 

 nected with the generating apparatus by a fairl}" stout piece of 

 rubber tubing. The cork supporting this part of the delivery 

 tube was attached to a small wooden axle, fitted near the cir- 

 cumference of a horizontal wheel which was driven by a small 

 air engine. The wheel revolving carried the tube round with 

 it, causing it to describe a circular motion in the liquid. Bj'' 

 means of this arrangement, the liquid could be stirred much 

 more effectively than by having the delivery tube stationary 

 and using another rod to do the stirring. To prevent the end 

 of the delivery tube from freezing up, a piece of copper wire 

 was placed in that part of the tube dipping into the liquid, and 

 then bent up almost parallel to itself and fastened loosely to the 

 side of the vessel containing the solution. The circular motion 

 of the delivery tube caused it to have a motion relative to the 

 wire thus preventing it from becoming frozen up. During a 

 part of the experiment the solution was simply surrounded with 

 ice. As far as I could determine, the same results were obtained 

 at this higher temperature, so long as the liquid was kept well 

 stirred. The sulphur dioxide was passed in until the liquid became 

 slightly acid, and the odour of the gas became perceptible. This 

 operation took about one hour for every 100 gms. of sodium car- 

 bonate taken. The solution thus prepared was then heated gently, 



