ON THE ELECTRICAL PROPERTIES OF PURE SULPHUR. 
127 
Table XT. — Resistance of Film of Mixed Sulphur of November 9th, ] 892. 
Date. 
Voltage. 
Resistance. 
Specific 
resistance. 
Tempera¬ 
ture of 
sulphur. 
Tempera¬ 
ture 
of air. 
Remarks. 
1892. 
volts. 
ohms. 
C.G.S. 
° C. 
c C. 
Nov. 9 
265-3 
7-358 x 10 11 
4-178 x 10 3i 
22-8 
22-8 
Directly after cooling 
„ 9 
Half of above 
Half of above 
55 
In fifteen minutes 
„ io 
264-1 
8-9 x 10 u 
5-5 x IO 3 * 
22-6 
5 5 
After voltage had been 
applied for lialf-an- 
hour. The resistance 
was not affected by 
blowing in damp air 
„ 11 
268-4 
3-296 x 10 13 
1-87 x 10 25 
19-9 
20-3 
Discontinuous conduction. 
Battery only one way 
„ 17 
262-8 
8-75 x IO 13 
5-02 x IO 25 
21-4 
20-5 
Battery both ways 
„ 17 
1 2115 x 10 13 
6-88 x 10 2 * 
61-8 
5J 
Ten observations. Bat¬ 
tery both ways 
„ 17 
55 
4-945 x 10 10 
2-836 x IO 33 
100-5 
Battery both ways 
The resistance results may be summed up as follows :— 
(1.) The mixed sulphur film is at least 1000 times more conducting than the purely 
crystalline film. 
(2.) The resistance changes from day to day, independently of the surface action, 
and is always less (a) when the voltage is first applied, (b) when it is reversed (at 
ordinary temperature). 
(3.) The resistance is discontinuous, particularly when the battery is first applied. 
(4.) The resistance decreases nearly two hundredfold between 28° and 100° C. 
(5.) Dampness cannot increase the surface action beyond a certain point; thus 
with our arrangement it could not bring the apparent specific resistance down below 
10 23 C.G.S. 
Film of November 18th, 1892. 
An attempt was made to increase the amount of insoluble sulphur present by cool¬ 
ing the plates more rapidly. With this object in view the sulphur and plates were 
heated up to 260° C., and kept at that temperature for half-an-hour. During the 
heating (which was carried out in an improvised air bath) a stream of pure carbon 
dioxide, dried by calcium chloride only, was allowed to flow into the air bath. In 
spite of this some of the sulphur caught fire. The plates were cooled by placing the 
dish on a block of ice, and covering the upper plate with a zinc tray filled with ice. 
By this means the metal plates, and with them the sulphur, were reduced to a 
temperature of nearly 0° C. in less than five minutes. The cooling at the commence¬ 
ment was very rapid, and no water got on to the film or into any part of the 
apparatus. Several analyses were made of the material from the dish, but they varied 
between 5 per cent, and 7 per cent, only ; rather to our surprise. We believe, 
