L388 LORD RAYLEIGH AND PROFESSOR W. RAMSAY ON ARGON, 
The hypobromite was prepared from commercial materials in the proportions 
recommended for the analysis of urea—100 grams. caustic soda, 250 cub. centims. 
water, and 25 cub. centims. of bromine. For our purpose about one and a half times 
the above quantities were required. The gas was liberated in a bottle of about 
900 cub. centims. capacity, in which a vacuum was first established. The full quan- 
tity of hypobromite solution was allowed to run in slowly, so that any dissolved gas 
might be at once disengaged. The urea was then fed in, at first in a dilute condition, 
but, as the pressure rose, in a 10 per cent. solution. The washing out of the 
apparatus, being effected with gas in a highly rarefied state, made but a slight 
demand upon the materials. The reaction was well under control, and the gas could 
be liberated as slowly as desired. 
In the first experiment, the gas was submitted to no other treatment than slow 
passage through potash and phosphoric anhydride, but it soon became apparent that 
the nitrogen was contaminated. ‘The “‘inert and inodorous” gas attacked vigorously 
the mercury of the Tépler pump, and was described as smelling like a dead rat. As 
to the weight, it proved to be in excess even of the weight of atmospheric nitrogen. 
The corrosion of the mercury and the evil smell were in great degree obviated by 
passing the gas over hot metals. For the fillings of June 6, 9, 13, the gas passed 
through a short length of tube containing copper in the form of fine wire, heated by 
a flat Bunsen burner, then through the furnace over red-hot iron, and back over 
copper oxide. On June 19 the furnace tubes were omitted, the gas being treated 
with the red-hot copper only. The results, reduced so as to correspond with those 
above quoted, were— 

Jwne @ » 5 © o 6 bo. BwoOrs 
m Qo ee Te Ree ae ene Oe 
SR IKDW pele uetaed Maal hy cous tac SmI O oi 
CSO et eee eto Og or 
Mean . W299 8i5 
Without using heat it has not been found possible to prevent the corrosion of the 
mercury. Even when no urea is employed, and air simply bubbled through the hypo- 
bromite solution is allowed to pass with constant shaking over mercury contained in 
a U tube, the surface of the metal was soon fouled. When hypochlorite was 
substituted for hypobronute in the last experiment there was a decided improvement, 
and it was thought desirable to try whether the gas prepared from hypochlorite and 
urea would be pure on simple desiccation. A filling on June 25 gave as the weight 
2°3243, showing an excess of 36 mgs., as compared with other chemical nitrogen, and 
of about 25 mgs. as compared with atmospheric nitrogen. A test with alkaline 
pyrogallate appeared to prove the absence from this gas of free oxygen, and only a 
trace of carbon could be detected when a considerable quantity of the gas was passed 
over red-hot cupric oxide into solution of baryta. 
