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acid ; the results showing, that not only the quantity of that acid de- 

 composed is constant for a constant quantity of electricity, but that, 

 when it is compared with water, by making one current of electricity 

 pass through both substances, the quantities of each that are decom- 

 posed are very exactly the respective chemical equivalents of those 

 bodies. The same current, for example, which can decompose nine 

 parts by weight of water, can decompose thirty-seven parts by weight 

 of muriatic acid, these numbers being respectively the chemical equi- 

 valents of those substances, as deduced from the phenomena of ordi- 

 nary chemical action. 



Cases of decomposition are then produced, in which bodies ren- 

 dered fluid by heat, as oxides, chlorides, iodides, &c, are decomposed 

 by the electric current, but still in conformity with the law of con- 

 stancy of chemical action. Thus the current which could decompose 

 an equivalent of water, could also decompose equivalents of muriatic 

 acid, of proto-chloride of tin, of iodide of lead, of oxide of lead, and 

 of many other bodies, notwithstanding the greatest differences in their 

 temperature, in the size of the poles, and in other circumstances ; and 

 even changes in the chemical nature of the poles or electrodes, and 

 in their affinities for the evolved bodies, occasioned no change in the 

 quantity of the body decomposed. 



The author proceeds, in the last place, to consider a very important 

 question with relation to chemical affinity, and the whole theory of 

 electro-chemical action, namely, the absolute quantity of electricity 

 associated with the particles or atoms of matter. This quantity he 

 considers as precisely the same with that which is required to sepa- 

 rate them from their combination with other particles when subjected 

 to electrolytic action and he brings many experiments to bear upon 

 this point ; describing one, in particular, in which the chemical action 

 of 32 - 5 parts of zinc, arranged as a voltaic battery, was able to evolve 

 a current of electricity capable of decomposing and transferring the 

 elements of 9 grains of water, being the full equivalent of that num- 

 ber. The relation of electricity, thus evolved, to that of the common 

 electric machine is pointed out in a general way, and the enormous 

 superiority as to quantity, in the former mode of action, is insisted 

 upon. In conclusion, the author refers to a statement which he has 

 made in the third series of these researches, in which he expresses his 

 belief that the magnetic action of a given quantity of electricity is also 

 definite ; and he is now more confident than ever that this view will 

 be fully confirmed by future experiment, 



The reading of a paper, entitled, "An Inquiry into the Nature of 

 Death ; being an attempt to ascertain its more immediate causes, 

 with a view to the better regulation of the means of obviating them." 

 By A. P. W. Philip, M.D., F.R.S. L. & Ed.— was commenced, 



u 2 



