216 Dr. L. J. Blake on the electrical Neutrality of 
70 Scale-divisions = 1 Daniell. 
Sea- 
water. Room temperature. 
Experiment. 
Keedle's 
position of 
rest before 
the experi- 
ment. 
Beading 
after 5 
minutes" 
insulation. 
JSeedle's Change of 
position of position of 
rest after rest during 
the experi- the experi- 
ment, m ent. 
Charge of 
needle in 
5 minutes. 
1 
2 
690 
571 
6890 
569-5 
690 Oscale-diy. 
570 +1-0 „ 
-fl-Oscale-div. 
+05 „ 
Sea-water. 100° C. 
l 
2 
689 
568 
691 690 
567 567-5 
— rOscale-div. 
+0-5 „ 
— l-0scale-div. 
+0-5 „ 
The Tables indicate so slight a difference in the electrical 
action between cold and hot sea-water (and, what is more im- 
portant, a difference not always of the same sign), that one is 
as little entitled here as in the first-described method of expe- 
riment to assert that a production of electricity by simple eva- 
poration has been shown. 
II. Electrical Neutrality of Vapour arising from 
electrified Still Surfaces of Liquids*. 
The second hypothesis to be tested is, that a convection of 
the electricity occurs by means of the vapour arising from the 
surface of an electrified liquid. An experimental research of 
the validity of this hypothesis was conducted in the following 
outlined methods. 
(a) The movable plate A of the Kohlrausch condenser still 
remained in connexion with the needle of the electrometer. 
Upon the stationary collector plate B a water-stratum was 
deposited through condensation of warm-water vapour. B was 
then gently heated and connected with one pole of a galvanic 
battery, whose other pole was connected with the earth. The 
cooler plate A was then brought to a distance of 1 millim., 
and the vapours passing from B condensed copiously upon A. 
There occurred, however, no convection of the electricity, 
notwithstanding that the vapour originated in a water-surface 
containing one of the two electricities accumulated in the 
condenser. Experiments were begun with a weak potential- 
* Compare L. J. Blake, "Ueber die elektrische Neutralitat" etc., 
Sitzungsberichte der Kgl. Akad. der Wissensch. zu Berlin, 1882, Nr. xxix. 
15 June, p. 635. 
