Mr. J. St. -Clair Gray on the Origin of Nerve- force. 413 



A difficulty in all investigations of this class must necessarily 

 arise from the impossibility of determining the distance which 

 the waters, in each case, have passed through the several lodes. 

 It is consequently quite possible that samples of water may 

 have been examined which, after passing for long distances 

 through the enclosing rocks, may have ultimately entered the 

 veins a few feet only from the point at which they were collected. 



Should, however, one specimen of water be found to contain 

 appreciable amounts of the constituents of the vein from which 

 it issued, whilst another is comparatively, or entirely, free from 

 them, it might be inferred, all other conditions being the same, 

 that the first had traversed a greater extent of vein-matter than 

 the seeond. 



It is evident that much time must be expended and numerous 

 analyses made before reliable conclusions can be arrived at; and 

 should waters containing appreciable quantities of the consti- 

 tuents of the veins from which they have issued be discovered, 

 an important question will still remain unanswered, — Is the 

 water ascending through a metalliferous vein ever the medium 

 from which fresh deposits of mineral matter are being produced 

 at the present time ? or does it, on the contrary, take up and carry 

 away some of the constituents of the lode, giving rise to new 

 combinations and a re-arrangement of its elements ? That both 

 these actions may sometimes be going on simultaneously does 

 not appear improbable. 



LII. Origin of Nerve-force. By James St. -Clair Gray, 

 M.B.C.M., F.F.P. §• S.G., Assistant to the Professor of Me- 

 dical Jurisprudence, Glasgow University*. 



IN the < Chemical News' of date August 11, 1871, I drew 

 attention to the fact that, by the action of a solution of 

 caustic potash on sulphur and phosphorus, there was developed 

 an electric current of which the electromotive power, as regis- 

 tered by Sir William Thomson's electrometer, was greater than 

 that of a Daniell ; s cell, the ratio of the power produced being as 

 four is to three. 



The object which I had in view in first making the investiga- 

 tions above referred to, was to obtain some proof in support of a 

 theory which a considerable time ago occurred to me relative to 

 the source of the nerve-power. 



According to this theory, I assumed in the first place that the 



nerve-power had in it an electric element, but failed for some 



time to discover any satisfactory source whence this agency could 



be derived. After a lengthened contemplation of the various 



* Communicated by the Author. 



