Properties of Bees -wax and Lead Chloride. 141 



time, however, remaining the same. All the tests from which 

 these curves are drawn were made with 0*075 volt electro- 

 motive force. The curves a a a, bbb, cc c, fig. 6, are the dis- 

 charge-curves obtained in the three above experiments for 

 15° C., 57° C.j and 14° C, observations of the discharge in the 

 experiment for 61° C. not having been taken. The scale both 

 for conductivity and for time is the same exactly as that 

 employed in the curves AAA, C C C, fig. 5. All the curves 

 show a regular increase of resistance with electrification, the 

 increase being far more rapid at a high than at a low tempe- 

 rature. As was seen from the curve S T U, fig. 4, so also from 

 fig. 6 we learn that the conductivity is much greater at a high 

 than at a low temperature ; and we also see from the curves 

 A A A, B B B, C C C, D D D, that the general effect of testing 

 day by day appears to lower the conductivity. 



Electrification-curves E E E, F F F, G G G, H H H, fig. 7, 

 were obtained from four successive tests with the copper-box 

 condenser, and correspond with the temperatures 15° C, 60° C, 

 13° C, 61° C. respectively. Time is measured parallel to X, 

 the points and X corresponding to the moment of apply- 

 ing the battery ; and 50 minutes afterwards conductivity is 

 measured parallel to Y from a zero as far below X as the 

 point Y is above. Curve F F F is on a scale for vertical 

 distances one twentieth of that employed for the curves E E E 

 G G G, and HHH on a scale one fifth of that used with 

 E E E, G G G : that is to say, if the same scale were employed 

 for vertical distances for all four curves, the two for the higher 

 temperatures would be far above those for the lower tempera- 

 tures — in fact, would be off the paper altogether. For hori- 

 zontal distances (that is, for time) the same scale is employed 

 for all the curves. An electromotive force of 7*5 volts was 

 employed with all the experiments from which these four 

 curves were drawn. Although the curves are irregular, still, 

 on the whole, there is an increase of conductivity or diminution 

 of resistance with electrification ; and that this is probably due 

 to the chemical action of the current referred to above is shown 

 from the irregularity of the discharge- curve g gg obtained 

 after removing the battery in the test at 15° C. Curve h h h, 

 however, which is the discharge-curve for the test at 61° C, 

 does not show any such irregularity ; but then it must be 

 noticed that H H H, the charge-curve for this temperature, 

 indicates on the whole rather an increase than a diminution 

 of resistance by electrification. 



April 1st, 1878. 



