18 



Mr. J. Napier on Electrical Endosmosc. 



served it being too few. As I have never observed these re- 

 sults except with the acids, I am inclined to think the cause 

 to be what has been already stated, namely, the solution act- 

 ing as the electrode, thus exposing a surface of acid to water 

 in a state of excitement or tension sufficient to attract by its 

 exalted affinity that fluid, and cause an increase of bulk in the 

 cell, in a similar manner, as I shall endeavour to show in a 

 forthcoming paper, to that which causes a greater amount of 

 action at the positive electrode than at the negative in any 

 electrolyte, and with muriatic acid and copper, as already re- 

 ferred to in a former part of this paper, amounting occasion- 

 ally to five times that of the negative. 



I shall now give the results, in a tabular form, of a few ex- 

 periments made to determine the relation, if any, between the 

 measurable endosmose and electrical decomposition. 



The experiments were all made with the double cells of 

 three compartments ; the battery used being Wollaston's of 

 9-pair intensity ; the time of each experiment was sixteen 

 hours; the electrodes of platinum. The acids used were di- 

 luted as 1 to 25 water; solution of sulphate of copper the 

 same strength in all. 



Positive 

 solution. 



Glass 

 vessel 

 (interme- 

 diate). 



Negative Loss in 

 solution. ; positive. 



Change 

 in glass 

 vessel. 



Gain in 

 nega- 

 tive. 



Amount of deposit 

 on decomposition. 



Amount of 

 measura- 

 ble endos- 

 mose. 



SO 3 

 Water 



NO 6 

 Water 



HC1 

 Water 

 Water 

 Water 

 S0 3 CuO 



SO 3 

 S0 3 CuO 



SO 3 



HC1 

 S0 3 CuO 



HC1 



SO 3 

 Water 



HC1 



NO* 



SO 3 

 Common 1 

 salt ... J 



Water 

 Water 

 Water 

 Water 

 Water 

 Water 

 Water 

 Water 

 SO 3 

 SO 3 

 Water 

 Water 

 Water 

 S0 3 CuO 

 HC1 

 Water 

 Water 

 Water 

 Water 

 Water 



Water 



Water 



SO 3 



Water 



NO 5 



Water 



HC1 



S0 3 CuO 



S0 3 CuO 



SO 3 

 S0 3 CuO 



SO 3 



S0 3 CuO 



S0 3 CuO 



S0 3 CuO 



S0 3 Cu 



Water 



SO 3 

 Water 

 Water 

 Water 



Water 



Ounces 

 none 





Tff 



gain i 

 loss A 

 gami 

 gain ft 

 loss 3 



none 



Ounces, 

 loss ^ 

 none 

 loss ^ 

 gain | 

 loss 1^ 

 gain li 

 gain£ 

 gain i 



gain i 

 gain } 



loss i 

 loss 1 

 loss If 



lOSS -Jg- 



gain i 

 loss f 

 loss 1 1 

 loss If 

 loss -J- 

 loss f 



loss 1 



Ounces. 



non 

 1 



Grains, 

 not measurable 



1 



1 



10 

 33 

 M 



11 



30 



27 



53 



43 

 not measurable 

 evolution of gas 

 not measurable 

 not measurable 

 not measurable 



not measurable 



Ounces. 



1 



H 



* 



li 



H 



i 

 H 



The following table is of the same kind as the last, but the 

 time of action and the power of the battery varying, as stated. 



