Notice of Faraday s Discoveries in Electro-Chemical Decomposition. 57 



decomposed by a given quantity of galvanic power as our standard, we 

 shall find, if we proceed to operate on the chlorides of lead, tin, and silver, 

 that the quantities of each of those metals evolved, are always in definite 

 proportions ; and these proportions will closely agree with those deduced 

 from the chemical theory of definite proportions ; so that tlie numbers 

 which express the chemical equivalents of water, lead, tin,&c. will equally 

 express their electrical equivalents. 



Mr. Faraday has also removed a very material source of error, which 

 previously rendered very obscure the results of electro-chemical analysis, 

 by first teaching us accurately to discriminate between the primary results 

 of that decomposition, and the secondary results which may arise from the 

 substances thus primarily evolved, entering at the very moment into new 

 combinations with other materials in the solution subjected to the galvanic 

 influence, and thus effecting farther and very different secondary decompo- 

 sitions. For instance, in any solution containing water, the water will be 

 primarily decomposed into oxygen and hydrogen j and these nascent gases 

 may effect further decompositions in the other materials, which might often 

 be erroneously ascribed to the direct influence of electricity. 



We greatly regret that the narrowness of our space, and the pressure of 

 materials, must prevent our doing more in this number tiian giving a brief 

 explanation of the new nomenclature under which Mr. Faraday lias an- 

 nounced his discoveries, and the most concise annunciation of his general 

 laws; but we hope to return to this subject in our next, when also we 

 shall propose, as introductory to this branch of scientific enquiry, to give a 

 popular but precise view of the general laws of the philosophy of electro- 

 magnetism, or the doctrine of polar forces, the branch of physics which at 

 the present moment appears pregnant with the most important discoveries, 

 as to the general constitution of nature. Our readers who may have looked 

 into Prout's Bridgewatcr Treatise, will especially feel the justice of our 

 anticipations. 



hi explaining Mr. Faraday's nomenclature, we must first observe, that 

 liis terms are derived from the idea of an electrical current, from the posi- 

 tive to the negative poles of the electromotive apparatus ;* but still they 



• In this account of the direction of the electrical current, it must be observed, that 

 we speak of the current set in motion as proceeding externally along the conductor 

 employed to complcat the circuit, and as the phxnomcna materially depend on the 

 completion of the circuit, this conductor, the fil conjonctif of Ampere, requires a 

 distinct technical name; we would propose syzygy, a term already familiar in astro- 

 nomy. Now it is evident that the direction of this external current returning along 

 the Byzygy, will be the reverse of that which proceeds internally, or along the acid 

 interposed between the plates in each galvanic combination ; for internally the cm-- 

 rent must be towards the pole from which it issues externally ; or, to use Faraday's 

 expressions, the anode and exode of the syzygy, and that of the electromotor must 

 be inverted. Obviously as this arises from tlic idea of a current proceeding along 

 the opposite sides of a continuous circuit, it has often been neglected, with great 

 confusion both of thought and language. 



No. 1.— Vol. I. , 



