A NEW CONSTITUENT OF THE ATMOSPHERE. 207 
The air thus obtained was treated exactly as ordinary air had been treated in 
determinations of the density of atmospheric nitrogen. Oxygen was removed by 
red-hot copper followed by cupric oxide, ammonia by sulphuric acid, carbonic anhy- 
dride and moisture by potash and phosphoric anhydride. 
The following are the results :— 








Globe empty July 10,14 . . . A) BLED 
Globe full September 15 (twelve eee aah "50286 
Wierohtiofgcast tae mae oa cea ne Ue eno S 
Ordinary atmospheric nitrogen . . . . . 2°31016 
Ditterencew ete ee oe et 00487 
Globe empty September 17. . . ee os 45 
Globe full September 18 (twelve Rae ah DIS) 
Weight of gas. . . sia alse beh m Says 
Ordinary atmospheric nitrogen . . . . . 2'31016 
Witterences 1 ape gat ee ee OLS 
Globe empty September 21 . . . 2 ne 2592320 
Globe full September 20 (twelve bie) eee 51031 
WEGENORGS er Shs Le Ue a PES) 
Ordinary atmospheric nitrogen . . . . . 2°31016 
Difteten ces) siti vd gente niece ee s00278 
Globe empty September 21, October 30 . . 2°82306 
Globe full September 22 (twelve pipes) . . 51140 
Weight of gas. . . se agen ene seam 311 LOG 
Ordinary atmospheric nitrogen . . . . . 2°31016 
Ditterencem aa hn eee ee ett ie O 
The mean excess of the four determinations is (00262 gram., or if we omit the first, 
which depended upon a vacuum weighing of two months old, ‘00187 gram. 
The gas from prepared air was thus in every case denser than from unprepared air, 
and to an extent much beyond the possible errors of experiment. The excess was, 
however, less than had been expected, and it was thought that the arrangement of 
the pipes could be improved. ‘The final delivery of gas from each of the groups in 
parallel being so small in comparison with the whole streams concerned, it seemed 
possible that each group was not contributing its proper share, and even that there 
might be a flow in the wrong direction at the delivery end of one or two of them. To 
