ould have changed gradually as the heat became communicated
to the brass, whereas no such change occurred, the resistances being
absolutely steady. Moreover, even the fusion of the selenium would not
produce any such change.

The "U B" property does not ordinarily change the resistance of the cell
to exceed ten times, i.e., the resistance with a weak current will not be
over ten times as high as with a strong one. But I have developed the "L
B" property to a far higher degree. Table C gives some recent results
obtained with L B cells, including one whose resistance, with 25 elements
Leclanche, was 11,381 times as high as with 8 elements, and which, after
standing steadily at 123 ohms (and then at 325 ohms with 1 element), on
receiving the current from 25 elements again returned to its previous
figure of 1,400,000 ohms.

TABLE C.

SENSITIVENESS TO CHANGE OF BATTERY POWER.
-----------------------+------------+------------+-------------
| Resistance | Resistance |
No. of cell. | with 25 | with 5 | Ratio of
| elements. | elements. | Change.
-----------------------+------------+------------+-------------
| ohms. | ohms. |
3/8 inch square, No. 1 | 40,000 | 30 | 1,333 to 1
3/8 " " " 2 | 13,000 | 40 | 325 "
1/4 " " " 1 | 1,400,000 | 123[8] | 11,381 "
1/2 " " " 2 | 500,000 | 62 | 8,064 "
1/2 " " " 5 | 3,500 | 21 | 167 "
Full size, No. 81 | 68,000 | 121 | 561 "
" " " 82 | 9,000 | 64 | 140 "
" " " 83 | 17,300 | 74 | 233 "
" " " 119 | 35,600 | 19 | 1,894 "
-----------------------+------------+------------+-------------

[Footnote 8: This measurement was obtained with 8 elements.]

The results in the table were obtained by changing the strength of
current by throwing in more or less of the battery. Like results can be
obtained by varying the current through the cell by any of the other
methods before specified. The above measurements were in dark.

5. _Dual state of selenium_.--My cells, when first made seem to have two
states or conditions. In one, their resistance is very low, in the other
it is high. When in the low state they are usually not very sensitive, in
any respect. I