ELECTRIC DISCHARGE WITH THE CHLORIDE OF SILVER BATTERY. 487 
end of the horizontal tube. The positive terminal of B was connected to the right 
end of the horizontal tube, and its negative to the bottom of the vertical tube. The 
photograph from which this figure is copied was obtained in half a second. 
Plate 36, fig. 20, represents the discharge through hydrogen at a pressure of 
0‘46 m.m., 605 M, batteries A and B, each of 3600 cells, the positive pole of A was 
1 connected with the left end of the horizontal tube, its negative to the top of the 
i vertical, 2,600,000 ohms external resistance having been introduced in the discharge ; 
the positive of B battery was connected to the right hand end of the horizontal tube, 
and its negative to the bottom. In neither set of discharges are distinct strata pro¬ 
duced at the positive end, and only after passing the cross are such produced. It 
would almost seem that the resistance introduced in one pair of branches had offered 
an impediment to the discharge in the other. 
Effect on strata of the shape of the positive terminal. 
Experiments were made in order to ascertain whether the form of a point used as 
a positive terminal had any effect on that of the strata. It was found, however, that 
whether the terminal was carefully shaped as a paraboloid, or was simply cylindrical, 
the strata took precisely the same form as is shown in Plate 35, where fig. 7 represents 
the discharge in hydrogen from a paraboloidal point, and fig. 8 that from a cylindrical 
point. 
Complex strata. 
The complex configuration of strata in many cases appears to us to present a great 
difficulty in accounting for their production, and in forming a clear conception of the 
forces which hold the molecules composing them so persistently together. Usually 
there is a dark space between the negative terminal and the last stratum on the 
positive side, but not unfrequently the last stratum or several strata thread them¬ 
selves on to the negative when it consists of a wire, as, for instance, in tube 346, 
shown in Plate 35, fig. 9, containing hydrogen at a pressure of 0'5 m.m., 658 M, with 
a battery of 3600 cells, and an external resistance 200,000 ohms, producing a current 
of 0'00238 ampere. A beautiful bracket-like series of strata was produced, two or 
three of which threaded themselves on to the negative, as is distinctly shown in 
Plate 35, fig. 9. Looked at from the end it could be seen that these strata had 
circular holes in them larger than the negative wire, so that a small dark space was 
left. Each stratum consists of an outer bracket convex towards the negative and an 
inner chord (fig. 12). 
Fig. 12. 
3 R 2 
