TRAVERSED BY CATHODE RAYS. 
(i'J 
Table VII. — Nitrous Oxide and Air. 
Air in both chambers at 
759 millims. 
Nitrous oxide in A at 
499 millims. 
Air in B at 759 millims. 
Ionization in A. 
Ionization in B. 
Ionization in A. 
Ionization in B. 
1-08 
1-00 
1-03 
1-00 
1 TO 
1-21 
55 
1-24 
1T5 
55 
1T2 
1-07 
55 
•99 
5 J 
IT 3 
55 
1-08 
1-07 
55 
1T1 
5 J 
1T7 
55 
1-23 
?? 
1-02 
5 5 
1-07 
57 
1-05 
5 5 
1T2 
55 
1T0 
55 
1T1 
1-00 
1T0 
i-oo 
Care was taken to insure the purity of the gases, and they were also well dried 
before being passed into the ionizing chamber. 
The oxygen was prepared electrolytically, and was freed from ozone by being passed 
through a strong solution of potassium iodide and caustic potash. 
The nitrogen was prepared by gently heating a mixture of ammonium chloride with 
a nearly saturated solution of sodium nitrite. The gas given off was passed through 
a U-tube containing strong caustic potash, and also through a second containing 
concentrated sulphuric acid. A Kipp apparatus was used for the preparation of carbon 
dioxide, which was made in the ordinary manner by allowing dilute hydrochloric acid 
to act on marble. In making hydrogen a Kipp apparatus was also used, dilute 
sulphuric acid being allowed to act on zinc. The gas was passed through a strong 
potassium permanganate solution, and then through a U-tube containing a strong 
solution of caustic potash. 
The nitrous oxide was prepared by heating ammonium nitrate in a flask, and the 
gas was collected over water. 
