JJ4. MR CONNELL ON THE ACTION OP VOLTAIC ELECTRICITY 



when a platinum capsule was substituted for the watch-glass, gas arose from 

 both poles, as had also been observed in the case of alcohol, holding a sunilar mi- 

 nute quantity of potash in solution. 



A small quantity of chloride of calcium, when dissolved in the spirit, had 

 also the effect of increasing the action, gas appeai-ing at the negative pole, and 

 none at the positive in glass vessels. 



The most minute quantity of potash wliich could be employed was found to 

 have the effect of increasing the action. When only lissnuth part was dissolved, 

 the evolution of elastic fluid at the negative pole could be distinctly obsei-ved in 

 a watch-glass with fifty pairs of 2-inch plates ; the pure spu-it itself, under such 

 circumstances, scarcely shewing the slightest action.* 



Although no distinct formation of carbonate of potash was obsen^ed when 

 small quantities only of potash were held in solution, the case was different when 

 a strong solution of the alkali in pyroxylic spirit was acted on. A small quan- 

 tity of such a solution was exposed to the agency of thirty-six pairs of 4-inch plates 

 in a tube, with parallel platinum-foil poles placed at the distance from one another 

 of about I'isth of an inch. In this case a copious evolution of elastic fluid took place 

 from the negative pole as usual ; but gas also arose, although in less quantity, 

 from the positive, owing to the greatly increased action from the concentration 

 of the liquid, and also to the nmo notable quantity of water in the hydrate of po- 

 tash dissolved. The liquid boiled in a few minutes, and soon acquired a red co- 

 lour ; and a good deal of white matter was deposited, which proved to be carbo- 

 nate of potash. The red hquid acquired a strong peculiar odour, and when mixed 

 with water became muddy, and got a yellow tint, evidently from the separation 

 of oily or etherial matter which had been formed during the action. 



The true nature of the voltaic action in all ' he experiments which have been 

 detailed appears to be sufficiently obvious. Water is decomposed, as was the case 

 when alcohol was employed instead of pyroxylic spirit. Its hydrogen is evolved 

 at the negative pole, whilst its oxygen is employed in giving rise by a secondary 

 action to the formation of smaU quantities of resinous, oily, or etherial matter, 

 and also carbonic acid when the action is energetic. In the last described expe- 

 riment, the quantity of as generated at the positive pole being larger than in the 



* If any one should imagine that the water of the hydrate of potash employed has any effect on 

 these experiments, he is at liberty to calculate the quantity of water in ifioBot'i part of potasli, held in 

 solution by a few drops of spirit contained in a watch-glass. gain, the quantity of spirit acte<l on in 

 the experiment in the preceding page, contained .16 of a grain of hydrate of potash, which contains .03 of 

 water, equivalent to .l.'J4 of a cubic inch of hydrogen. But above two cubic inches of hydrogen were 

 collected, and the process was stopped while the evolution was going on. Similar observations apply to 

 the experiments with alcohol. The true action of the potash in these cases is just the same as when it 

 is dissolved in water itself. It increases the conducting power of the liquid, aided, in the case of alcohol 

 and pyroxylic spirit, by a circumstance to be noticed immediately. 



