ON ELECTRO-CIIEMIGAL EXPERIMENTS', J 7.5 



rtrsenters having employed very considerable power without 

 effect, it may be useful to describe that peculiar attention, 

 which has been proved by experience most calculated to en- 

 sure success. 



From a series of experiments made for the express pur- Bast mode of 

 pose of ascertaining the best mode of employing the Voltaic u P ? t °f a 

 battery, which I shall at a future period lay before the pub- compositions 

 lie, I have found, that the most usual is by far the worst 

 that can be adopted when the instrument is intended for 

 experiments of decomposition; this operation requiring the 

 continued action of a power of nearly uniform intensity, a 

 circumstance that rarely occurs in the ordinary mode of 

 charging. By far the greater number of experimenters es- 

 timate the acting power of their instruments by the quan- 

 tity of wire a given number of plates will fuse; and consi- 

 der them most advantageously excited, when they fuse the 

 greatest length. To attain this object, if the battery is not 

 of great extent, a strong acid mixture is employed. Thi* 

 produces violent action for a short time, but which gradually 

 decreases, and in a very limited period ceases altogether. 

 The power thus excited, which I call the wire-melting 

 p»wer, is by no means desirable but for the performance of 

 brilliant experiments ; the most extensive and interesting 

 class of chemical compounds being either partial conduc- 

 tors, or nonconductors, on which this action will be found 

 less efficacious than a more moderate intensity. 



The most active wire-melting power I have yet excited Most effective 



was by a mixture of one part strong nitrous acid, and ten V ovl V * or . 



. , , , ,. '. (. & . . melting wire, 



parts water, with the addition or a very minute portion of 



muriatic acid; but from some observations I have recently 



made, I am induced to believe this mixture should never 



be employed in an apparatus used for general experiments. 



Three similar batteries were charged with equal propor- Comparati?* 



tions of the different acids, that charged with nitric acid P owers of th * 



fused the greatest portion of wire, that with sulphuric acid ac i<j s . 



the next in quantity, and that with muriatic acid the least: 



their action ori imperfect conductors was nearly similar. At 



the end of 14 hours they were again tried; the battery 



charged with nitric acid had completely lost its wire-melt- 



iqg power, as had also that charged with sulphuric acid, 



