208 LORD RAYLEIGH AND PROFESSOR W. RAMSAY ON ARGON, 
meet this objection, the arrangement in parallel had to be abandoned, and for the 
remaining experiments eight pipes were connected in simple series. The porous 
surface in operation was thus reduced, but this was partly compensated for by an 
improved vacuum. ‘Two experiments were made under the new conditions :— 




Globe empty, October 30, November 5 . . = 2°82313 
Giobe full, November 8 (eight pipes) . . . 50930 
Wreightiofigas) Nace ee ae .  2°31383 
Ordinary atmospheric nitrogen . . . . . 2°31016 
Difference. cl a es tee ee 008 bir 
Globe empty, November 5,8... . . . 2°82355 
Globe full, November 6 (eight pipes) . . . 51011 
Wieiehtiol gas: 05. Si Gees ike etme oa 
Ordinary atmospheric nitrogen . . . . . 2°31016 
Difference: 4a ee, Eee eee OO R26 
The excess being larger than before is doubtless due to the greater efficiency of 
the atmolysing apparatus. It should be mentioned that the above recorded experi- 
ments include all that have been tried, and the conclusion seems inevitable that 
“ atmospheric-nitrogen ” is a mixture and not a simple body. 
It was hoped that the concentration of the heavier constituent would be sufficient 
to facilitate its preparation in a pure state by the use of prepared air in substitution 
for ordinary air in the oxygen apparatus. The advance of 3} mg. on the 11 mg., 
by which atmospheric nitrogen is heavier than chemical nitrogen, is indeed not to be 
despised, and the use of prepared air would be convenient if the diffusion apparatus 
could be set up on a large scale and be made thoroughly self-acting. 
7. Negative Experiments to Prove that Argon 1s not derived from Nitrogen or 
From Chenucal Sources. 
Although the evidence of the existence of argon in the atmosphere, derived from 
the comparison of densities of atmospheric and chemical nitrogen and from the 
diffusion experiments (§ 6), appeared overwhelming, we have thought it undesirable 
to shrink from any labour that would tend to complete the verification. With this 
object in view, an experiment was undertaken and carried to a conclusion on 
November 13, in which 3 litres of chemical nitrogen, prepared from ammonium 
nitrite, were treated with oxygen in precisely the manner in which atmospheric 
nitrogen had been found to yield a residue of argon. In the course of operations an 
