43G 
DIG IIAEOLI) A, WILSON OX THE 
The f'ollowino; table o-ives the maximum currents observed vith KI, KCl, and 
K.iCOg, and the currents recjuired to electrolyse the same amount of each in a 
solution :— 
Salt. 
Current. 
Current calculated. 
Ratio. 
KI . . . 
7 X 10“^ 
8-5 X 10-* 
0-82 
KCl . . . 
. 15 X 10-J 
18-9 X 10"^ 
0-80 
K,C()3 . . 
. 10 X io-‘‘ 
20-4 X 10-^ 
0-79 
It thus appears that the maximum amount ot current carried by the vapours is 
nearly eijual to the maximum amount the same bodies could carry in a state of 
solution. This agreement must be regarded as considerable evidence in favour of the 
view that tlie ions are of the same nature in the two cases. 
5. Summary of Results. 
(1.) The variation of the current between jdatinum electrodes in air Avith the 
temperature may be expressed approximately l)y a formula of the tyjje A^", where 
9 is the al)Solute temperature and A and n constants. The value of n was about 17 
when the E.M.F. used Avas 240 volts, and 13 Avith 40 Amlts. 
(2.) The energy recjuired to ionize 1 gramme molecular Aveight of air is about 
00,000 calories betAveen 1000° and 1300°. 
(3.) The current through a halogen salt va})our in presence of air and AA^ater reaches 
a maximum A^alue near 000°, and then falls as the temperature rises. Near 1100° it 
again rises rapidly Avith tlie temperature. 
(4.) The energy recpured to ionize 1 gramme molecular AA^eight of Kl is about 
15,000 calories at about 300°. 
(5.) The maximum current carried by a detinite amount of salt A*apour is nearly 
et[ual to the cui'rent recfuired to electrolyse the same amount of salt in an aqueous 
solution."^ 
In conclusion, I Avish to say that my best thanks are due to Professor J. J. 
Thomson for much kindly interest and adAuce throughout the course of the work 
described in this ])aper. 
* Eoi' similar results with nineteen ditferent alkali salts see Appendix. 
