10 ART. la. — T. HAGA : 



the ends drawn out and bent, first, upwards and, then, horizontal- 

 ly, in the one case, downwards, in the other, as shown in the 

 figure. 



After replacing all the air in the tube by means of a current 

 of carbon dioxide, passing in at one end and out at the other, 

 which was kept under mercury, sulphur dioxide was passed in, 

 until it replaced the carbon dioxide and saturated the solution in 

 tlio tube. The tube was then sealed up near the two ends and 

 the whole was left for two days. It was then connected with 

 the Sprengel pump at the end, which had the downward bend, 

 by means of a thick india-rubber tubing, and the pump was set 

 in action. As soon as the air was exhausted the sealed end of 

 the tube was broken under the india-rubber tubing, and the gas 

 was pumped into a gas measuring tube, which contained a few 

 cubic centimetres of very strong potassium hydroxide. The pump 

 was worked slowly, in order that all the sulphur dioxide might 

 be absorbed by the potassium hydroxide. The residual gas was 

 measured, under a reduced pressure, over a column of mercury 

 plus a column of potassium hydroxide. 



From the specific gravity of the original potassium hydroxide 

 solution, the height of the latter was reduced to that of mercury, 

 although the specific gravity must have been considerably altered 

 by the absorption of sulphur dioxide and also the fact that even some 

 quantity of a solid salt had separated out. The gas, which must 

 have been practically dry, measured only 4.98 c.c. at 17°C. under 

 a pressure equal to 565 mm. of mercury. This quantity of the 

 gas would weigh 0.00827 gramme, if it consisted of pure nitrous 



