Intelligence and Miscellaneous Articles, 479 



(4) The goldbeaters' skin, when moistened with shellac, gave a 

 slowly diminishing deflection. 



(5) The dielectric was made by flowing the surfaces of the plates 

 with a solution of wax and gasoline ; and a slowly diminishing de- 

 flection was obtained. 



(6) The condenser used in (4) was tried again after the shellac 

 had dried, and again gave a diminished deflection, less than the first 

 deflection. 



(7) The condenser used in (5), when tried again after a day or 

 two, did not again give a deflection. 



(8) TJnglazed paper dry and oiled gave no deflection. 



(9) Grlazed paper oiled gave a very slight deflection, and the 

 galvanometer-needle immediately returned to zero. 



(10) Grlazed paper wet with water and covered with shellac gave 

 the greatest deflection of all the dielectrics. The light was sent 

 completely off the scale, and was only brought back by shunting the 

 galvanometer. The discharge also continued a long time. 



(11) The conducting-power of some of the various dielectrics was 

 tested. The goldbeaters' skin which had been covered with shellac 

 transmitted no current after it had been allowed to stand for a 

 week. Freshly oiled and dry oiled paper did not conduct at all. 

 Grlazed paper covered with shellac gave a deflection nearly off the 

 scale. Grlazed paper wet with water and covered with shellac trans- 

 mitted a current sufficient to send the fight entirely off the scale. 



What these experiments directly go to show are, first, that con- 

 densers with moist dielectrics received a greater charge than those 

 made with dry, and, second, that the better the dielectric conducted, 

 the greater the charge the condenser was capable of receiving. 

 From these facts it would seem that the slow discharge of these 

 condensers was very probably due to polarization. The best con- 

 densers, as shown by the experiments, possessed dielectrics which 

 were moist and possessed considerable conductivity. The dielec- 

 trics when dry scarcely conduct at all. Their conduction when 

 moist must therefore have been mainly due to electrolysis, since 

 liquids conduct electricity only in very small quantities without 

 being decomposed. The electrolyte was therefore decomposed ; and 

 the recombination of the products of decomposition caused the 

 return current. An exact analogy is thus determined between 

 the case of the lead plates and these condensers. Whether it is 

 an analogy that would hold in the case of all condensers which 

 slowly discharge themselves, is an interesting question. — Silliinan's 

 American Journal, September 1874. 



ON ELECTRICAL CURRENTS ACCOMPANYING THE NON-SIMULTA- 

 NEOUS IMMERSION OF TWO MERCURY ELECTRODES IN VARIOUS 

 LIQUIDS. BY G. QUINCKE. 



[The author, after a very full description in detail of a great 

 number of experiments (Pogg. Ann. vol. cliii. pp. 1G1-203), sums 

 up the results as follows.] 



