nh? Mr T. H. Easterfield, Some observations on [Oct. 31, 
the test tube was surrounded by ice-cold water. After the experi- 
ment had been allowed to go on for some time however, it was 
noticed that though the apparatus itself was perfectly colourless, the 
glass tubes of the water air-pump were distinctly pink. and became 
gradually more so as the experiment proceeded. The question 
naturally suggested itself, “Why should the evolved gases colour 
the tubes of the pump and not the neck of the retort and the test 
tube through which they had first passed?” The only answer to 
this question seemed to be that the tubes of the pump were moist, 
and that a gas was given off from the sulphuric acid and potassium 
permanganate which, though colourless by itself or in the absence 
of water, was dissolved by water with the formation of a pink 
solution. To test whether this supposition was correct, the evolved 
gases were now passed through a second test tube, to catch any 
spirtings which might possibly come over from the mixture in the 
retort, and then through bulbs containing distilled water, dry air 
being drawn through the retort, so as to remove the gases as fast 
as they were formed. In a few minutes the water in the bulbs 
became pink, and the sides of the entrance tube of the bulbs, 
being moist, first became pink, and afterwards dark brown in | 
colour. When the bulbs were subsequently rinsed out, it was 
found that though they themselves became perfectly clear, a brown 
deposit was left in this entrance tube, as though the body formed 
was stable in the presence of a large excess of water, but de- 
composed by a small quantity of the same liquid. The pink 
solution from the bulbs was reduced with oxalic acid, and then 
yielded a colourless solution, containing no trace of sulphuric acid 
or potassium, so that the coloration could not be due to spirtings 
from the retort. When the yield of the gas was good it was 
found that though the mixed gases were colourless before entering 
the bulbs, they were distinctly purple as they escaped from the 
exit end of the apparatus. 
A piece of wide glass tubing was now drawn off at each end to 
a thin tube, and the gases from the retort passed through it for 
some time. It remained perfectly colourless, but upon removing it, 
placing a few cc. of distilled water inside it, and shaking up, a 
pink liquid was obtained. This liquid was very faintly ‘acid to 
litmus paper. 
This experiment was repeated with a large dry flask, and gave 
similar results. 
Another piece of thick tubing, similar to that used in the last 
experiment, was now taken, and “after the gases had been passed 
through it for about half an hour, it was heated by a Bunsen 
lamp. A brown ring soon formed inside the tube, at each side of 
the point where the flame was applied, just as, in the case of 
decomposition of arseniuretted hydrogen, a black ring is formed. 
