composition, and at the same time increases many times in volume. The result is a mixture of mellon, itself a compound of carbon and nitrogen with sulphide of mercury, the latter substance being in a small proportion. The resulting mass is necessarily of slight specific gravity. It is extremely brittle, but the whole mass is sufficiently rigid to admit of its being raised in an unbroken form, if handled gently. Externally the coil presents a yellow colour, but internally it is black, and the fracture is evidently metallic. In the manufacture of the cones, or "eggs," as they are termed, in conformity with the idea which designates the product as "serpents," a little nitrate of potash is added, in order to enable the heat to be applied within the mass; and the contorted form of the ash is evidently attributable to the degree of homogeneity of the substance experimented upon, and the form in which it is made up. The decomposing property of the mercurous sulphocyanide is also possessed by the mercuric sulphocyanide, but the mercuric salt, which is used in the French serpents, contains a larger quantity of sulphocyanogen, and is therefore more likely to produce a larger volume of mellon. The mercuric sulphocyanide may be easily prepared by precipitating a strong solution of pernitrate of mercury by sulphocyanide of ammonium in as pure a state as possible. Another form of the experiment is to use the composition in a compressed state without foil at all. A small bit the size of a pea will produce a serpent of formidable proportions. These have been sold in Paris in shape and size strongly resembling a pastille de guimauve, and the French journal Les Mondes tells a curious story to the effect that a certain Prince O, mistaking one of the "eggs' for a bonbon of the luscious pâte, swallowed it, very nearly killing himself, but entirely destroying a tape-worm, which formed an unfortunate and unwelcome addition to his internal economy. The story is probably an invention of one of the witty journalists of Paris, but at any rate the inference might be dangerous, that so deadly a poison, though it might be an effective remedy for tape-worm, is also a safe one. VOL. VII. Ten of our number have been removed by death during the last year. Of these, 1. My kinsman, Mr Charles Chalmers, who was warmly attached to scientific pursuits, and published a journal devoted to science, in George Street, near where we are now met, entered the Society in 1827. 2. Mr Sclater, die-cutter, joined us in 1832. 3. Mr George Lorimer, in the discharge of his duty as Dean of Guild, was one of six that perished in the terrible conflagration of the theatre in January last, and sacrificed his valuable life in the vain but heroic attempt to save that of a fellow-creature. Mr Lorimer became a Fellow of the Society in 1838. 4. Dr David Maclagan, a much beloved and honoured citizen, also joined the Society in 1838, and was borne to the grave by his seven sons in June last. 5. Mr John Maitland, accountant to the Court of Session, a valuable officer, well known by his munificent acts, became a Fellow in 1841. 6. Mr J. Ronaldson joined the Society in 1844. 7. Mr John Donaldson, Professor of Music in the University, entered our ranks in 1846. 8. Mr J. M. Mitchell, Belgian consul, who joined us in 1850. 9. Mr David Hunter, chemist, in 1852; and, lastly, 10. Lieutenant-Colonel Macdougall, a gentleman who, both as an ordinary Fellow and a Councillor, took a most lively interest in the proceedings of the Society. I am glad to think that the sad blanks in our numbers have been much more than supplied by the entry of new Fellows, of whom thirty-five have been admitted in the course of the year, but twenty-eight have resigned, or been struck off for non-payment of their contributions, making the effective strength of the Society at this date 441, being a diminution of three upon the number at the beginning of the Session last winter. Allow me to express a hope that our ranks may be increased in number by the enrolment of employers of labour and others as new Members, who, I trust, will find that an hour spent here once a fortnight during the winter season is often fraught with useful information on the state and progress of the industrial world. Gentlemen, I have been for very nearly thirty years a Fellow of your Society. I regret that I should have been unable to attend the meetings of the Society more frequently, or to have been of more use to you; but in now leaving the chair, with a most grateful sense of the honour you have conferred upon me in placing me there, and of your indulgence towards me, allow me to assure you that there is no one amongst you who is more desirous than I am for the continued prosperity and usefulness of the Royal Scottish Society of Arts. I have the greatest confidence in the power of co-operation, when wielded by wise, earnest, honourable men for the good of their country. Many are the examples that might be cited around us, showing that, slowly it may be, but yet surely, truth will displace error, ignorance shall be dispelled, and knowledge be increased; and finally, in the beautiful words of inspired writ, the evil shall be overcome by the good. This Society is well fitted to bear its part, as it has hitherto done, in forwarding, in its own province, every object likely to benefit our species. 125 On Rendering Gunpowder Non-Explosive. By Lieut.-Col. J. S. G. RYLEY, H.E.I.C.S., Edinburgh,* late Bengal Cavalry. In consequence of the disastrous results caused by explosions of large quantities of gunpowder from time to time, and the awful disaster at Erith and other places not long ago, and subsequently the great alarm created some time since, owing to the very large quantity of gunpowder stored in Edinburgh Castle, my attention has been especially directed of late to the endeavour to devise some plan by which gunpowder might be rendered less dangerous. During the last twelve years upwards of fifteen serious explosions have been recorded in the public journals, by which more than 600 persons have been killed, and many thousand persons wounded, and property to the extent of more than two millions of pounds sterling has been destroyed. After various experiments, extending over a considerable time, I succeeded in discovering a simple, inexpensive, and most efficacious method, which, if adopted by the Government, will not only render unnecessary the enormous expense of erecting new magazines, but be the means of saving human life, and much valuable property, both public and private. The principle of my invention consists in filling up the interstices of the gunpowder, and thus thoroughly isolating the grains, with a non-combustible medium, which is required to be of very fine powder, so as to be readily and quickly sifted out again when the powder is required for use, and this property has been known to me for a long time. Whilst I have recently paid special attention to this department of the subject, I may state that for many years I have more or less devoted myself to the consideration of various matters connected with gunpowder. The great loss experienced when gunpowder is transported by land carriage in barrels, especially over the rude tracts in some parts of India, causes it to be much ground down to fine dust, which falls to the bottom of each barrel, and thus * Read before the Society, and experiments exhibited in illustration, 27th November 1865. Awarded the Society's Silver Medal. VOL. VII. R |