It will be observed that the amount of soluble matter in the first two specimens is small, and that the constituents do not differ materially from those which might be expected to occur in ordinary well-water from the same district. The third sample evidently consists of a mixture of sea-water with water derived from other sources. The solid contents, however, are considerably less than in sea-water, and consequently, in order to institute an approximate comparison between them, we will suppose sea-water to have been diluted with distilled water until the total amount of fixed constituents has been reduced to that contained in the water from Botallack. For the purposes of this comparison I have selected an analysis of water from the Irish Sea by T. E. Thorpe and E. H. Morton, in which the fixed constituents amounted to 33.8385 grammes per litre*. The water from Botallack afforded 14·2047 grammes of solid matter per litre; and therefore, if we multiply the several estimations of Messrs. Thorpe and Morton by 14.3047 ='4227, we obtain the respective amounts of the various 33.8385 constituents which would be present, in a mixture of water from the Irish Sea with distilled water, containing 14-3047 grammes of solid matter per litre. * Ann. Chem. Pharm. clviii. 122–131. In the above Table a general accordance will be observed between the figures obtained by analysis of the Botallack water and those calculated on an assumed mixture of sea-water with distilled water; it will be remarked, however, that lithium and large quantities of lime and carbonic acid have been taken up. A comparison of the figures in the two columns also renders it evident that magnesia has been in some way abstracted from solution, although the rocks in which the lode is enclosed have been found to contain much larger quantities of magnesia than of lime*. Copper, zinc, lead, tin, &c. were carefully sought for by the usual tests without success; but the spectroscope was only employed for examining the alkaline chlorides with the flame of an ordinary Bunsen gas-burner. It is, however, probable that traces of various substances, present in such minute quantities as to escape detection by ordinary means, might be found by spectroscopic observation with the assistance of a powerful induction-coil; and I therefore propose to make further investigations by the aid of this instrument, and also to operate on very large quantities of the various waters subjected to analysis. * Analyses of two of the clay-slates from this locality afforded respectively-lime 4.05, magnesia 6-58 per cent.; and lime 4.78, magnesia 11.61 per cent. Phil. Mag. February 1871. 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 second. 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 constituents 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 Medical Jurisprudence, Glasgow University*. אן N 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 registered 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 investigations 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. constituent elements of the body, it occurred to me that sulphur and phosphorus might be those to which I should look. Acting, then, from the fact that in the brain there was a very considerable proportion of phosphorus, that in the liver there was present a large proportion of sulphur, while between the two there was in constant circulation an alkaline fluid, the blood acting on these facts, and having in my mind the idea that nerve-power and an electrical current, if not identical, were closely related to each other, I constructed the cell already mentioned, with the above result. Having, then, by this experiment determined that an electric current was produced in the cell containing the sulphur and phosphorus in alkaline solution, I turned my attention to the actual conditions (the conditions found to exist in the living animal), and by the following experiment proved the existence between the brain and liver of an electric current. In the first place, the hind leg of a frog was prepared as a galvanoscope, according to the directions first given by Galvani, and which were followed out so carefully and successfully by Aldini and Matteucci; then to a rabbit 21 oz. in weight chloroform was administered till complete anesthesia was produced. An incision was then made through the abdominal walls in the right hypochondriac region, and through this aperture a properly insulated copper wire was passed into the substance of the liver; the cyeball was then pierced, and a similar piece of copper wire brought into contact with the brain by forcing it through the optic foramen. The free extremities of the copper wires were then brought into contact with the exposed sciatic nerve of the frog's limb, when powerful convulsions were induced in the muscles receiving their nervous supply therefrom. Having, then, by this experiment proved that between the brain and the liver there exists an electric current, it is, I think, quite feasible to assume that at least a portion, if not the whole, of this current is due to the action of the alkaline medium on the sulphur and phosphorus contained respectively in the liver and brain, which current we have already found to be produced in the sulphur-and-phosphorus cell. That in the animal economy other sources of electricity do exist I should be the last to deny; but that this, as a source of nervo-motor power, is perhaps second to none receives confirmation, I think, from a consideration of the amount of phosphoric acid excreted by the kidneys as phosphate of soda, potash, lime, and ammonia, amounting on an average to rather more than 72 grains per diem, and of sulphuric acid, as sulphate of soda and potash, amounting to nearly 100 grains, the oxidation-products of sulphur and phosphorus being in the main derived from the two organs in which they in the greatest proportion abound. Taking, then, for granted that we have here arrived, in part at least, at a solution of the source of nervo-motor power, I look upon the sympathetic nerve, its branches and ganglia, not as a separate or isolated system, but merely as a constituent part of the general nervous system-a part, however, to which is assigned the function of guiding and regulating the movements of involuntary muscular fibre, receiving from the common source its nervo-motor power, but moulding it to its own purposes and requirements; while I think it not at all impossible that in the great serous cavities of the body (the peritoneum, pleura, pericardium, and in those of the encephalon) we may find an arrangement to exist in many respects analogous to Leyden jars. These ideas may appear to many crude and imperfect; but the subject is still being investigated, and in a future Number additional facts shall be communicated. 15 Newton Terrace, Glasgow, September 4, 1871. LIII. On Canon Moseley's views upon Glacier-motion. THE 1. In every transverse section of a glacier every particle of ice is, at the same moment of time, moving over and alongside its neighbours. 2. The absolute motion of any point in the surface of a glacier is proportional to its distance from the nearest side, and to its height from the bottom of the channel. 3. This differential motion can only take place by the process which, in mechanics, is known by the name of shear. 4. The resistance which ice offers to shearing, or its shearingforce, as ascertained by experiment in the shearing-apparatus devised by Canon Moseley, is not less than 75 lbs. per square inch. 5. But in order that the Mer de Glace may descend by its own weight, at the rate at which Professor Tyndall observed it descending at the Tacul, its shearing-force per square inch cannot be more than 1.3193 lb. I propose in the present communication to examine these propositions. * Communicated by the Author. |