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النشر الإلكتروني

ON GUN COTTON AND OTHER XYLOIDS,

BY J. BAKER EDWARDS, PH.D., F.C.S., V.P.

The class of substances called Xyloids are produced by the action of Nitric acid upon vegetable bodies containing Hydrogen; and their formation is due to the removal of a portion of Hydrogen, and the substitution of a like number of atoms of Nitrous acid (N 04). Substitution compounds of this type are formed from Sugar, Gum, Starch, Cotton, Sawdust, &c., all of which are highly combustible or explosive. Thus we have from Starch

Starch a white powder called Xyloidine, thus produced-

Starch (C24 H20 020) + Nitric acid (N 05), produces1.-Xyloidine (C24 H19 N 04 020) + H 0.

Sugar (C24 H28 028) + Nitric acid (N 05), produces2.--Saccharoine (C24 H25 (3 N 04) 028) + 3 H 0.

Cotton, (C24 H20 020 + N 05) produces two compounds3.-Pyroxiline, a, (C24 H17 (3 N 04) 020) + 3 H 0.

Pyrowiline, b, (C24 H15 (5 N 04) 020) +5 H 0.

Glycerine (C6 HP 06), produces with N 05— 4.-Nitroglycerine, (C6 H6 (2 N 04) 06) + 2 H 0.

Benzene, a pure hydro-carbon (C12 H ), yields-5.-Nitrobenzene, (C12 H5 (N 04) ), + H.

These compounds, which may, with some others, be called the family of Xyloids, were at first regarded merely as chemical curiosities, but certain characteristics have brought several of them into more prominent notice lately. In 1859 I published a general review of their physiological properties,* and I now propose more especially to illustrate some of the more important chemical and physical properties of certain members of the group; but little additional information has been obtained in reference to the first of the group, viz., Xyloidine. This substance is pulverulent, and explodes when struck with a hammer; it however is readily decomposed, Nitrous fumes being evolved, and the residue becoming damp.

The second compound, Saccharöîne, is chiefly remarkable for its resin-oil character, its intense bitterness, and its physiological effects upon animals which, like its bitterness, to a certain extent, resemble Strychnine.

The third compound, Pyroxiline, has been greatly developed, and promises now to be a manufacture of national importance. Its first variety, a, is soluble in ether, producing Collodion, the surgical importance of which has been far exceeded by its value as an instantaneous photographic basis, which exceeds all previous menstrua. Dried collodion surfaces are also remarkable for their instant electrical excitement by friction. Pyroxiline b is of still greater importance, and its manufacture has recently assumed national distinction. The Governments of Austria and France, in succession, have instituted commissions to enquire into the capabilities of Gun Cotton as an explosive, in reference to its superiority over Gunpowder, but the difficulties in the way of obtaining a perfectly safe, definite, and permanent compound appeared for some time to be insuperable. These, however, have been overcome by Messrs. Prentice & Son, of Stowmarket, Essex,

+ The Liverpool Medico-Chirurgical Journal, No. 5, January, 1859. Greenwood and Churchill.

a small sample of whose productions I now exhibit, hoping on a future occasion more fully to illustrate them. They are prepared to produce continuously, and in large quantities, a quality of Gun Cotton of any required degree of explosive property, from the slow match to the bombshell charge. Uniformity in the chemical product is obtained by lengthened contact between the cotton and the oxidating agents, and stability is secured by long-continued washing and storage under water. The rapidity of combustion is regulated, as the flow of oil through a wick, by mechanical plaiting of the combustible yarn; and thus charges for the revolver, the rifle, or the cannon are readily and permanently adjusted. Mr. Abel, F.C.S., of the War Department, Woolwich, has rendered valuable assistance in bringing this manufacture to its present state of perfection.

Nitro Glycerine, or Glonoine, has an interest chiefly of a physiological character. It is a fluid, and is exploded into a large volume of free gases when suddenly compressed, or sharply struck. When taken internally, it produces in very minute doses intense headache, and in larger doses produces in animals convulsions and death. Latterly it has been extensively employed for blasting purposes, being ignited through water by means of a slow match, it produces effects more powerful than gunpowder, and can be applied with less labour than gun cotton.

Nitro Benzene, the last of the series now under consideration, differs from the preceding in containing no oxygen, except that existing as Nitrous acid. It possesses the remarkable odour of the essential oil of bitter almonds, and by de-oxidation is converted into that remarkable compound, Aniline, (C12 N H,) the base of the mauve and magenta dyes. This oily substance, called artificial oil of bitter almonds, is very largely used in perfumery and for culinary purposes, but not without considerable risk, as it has proved on several occasions, both by inhalation of its vapour, and by internal administration, to be a powerful narcotic poison, only less deadly in point of time, but even more insidious, than prussic acid itself.

The whole class of Xyloids may therefore be regarded with especial interest, chemically, physically, and physiologically.

N.B.—The communication was fully illustrated by experiments and specimens, exhibiting the reactions and properties of specimens of the series manufactured by the author. The various modifications of Gun Cotton ordnance produced by Messrs. Prentice, which were forwarded for the occasion, did not arrive in time but were exhibited to the Society on a subsequent occasion.-Vide page 231.

ELEVENTH ORDINARY MEETING.

ROYAL INSTITUTION, March 20th, 1865.

J. A. PICTON, Esq., F.SA., PRESIDENT, in the Chair.

Mr. Picton explained, with the aid of a plan, the proposed new approaches to the Landing Stages, now under the consideration of the Council.

Dr. Collingwood drew attention to the recent discoveries of Agassiz on the metamorphoses of fishes, and to those of M. Gerbe upon the probable larval character of Phyllosoma ; and made some general remarks upon the tendency of these discoveries, which led to a conversation upon the subject of metamorphoses and embryonic changes, in which the President, Mr. Moore, Rev. H. H. Higgins, Dr. Collingwood, and others took part.

Mr. T. J. Moore exhibited specimens of a very fine Gorgonia (Lophogorgia palma), and of a species of Ísis, from Port Elizabeth, South Africa, lately presented to the Derby Museum by Mr. Councillor A. C. Stewart.

Mr. Moore then brought before the society a large number of birds, reptiles, fishes, &c., lately collected in the neighbourhood of Lagos, West Africa, by Mr. R. B. N. Walker, and presented to the Derby Museum. This gentleman, some three years since, arrived in England from the Gaboon, bringing with him, among other remains of gorillas, the magnificent skeleton which he then gave to the museum, and has since been one of its greatest attractions. On his return to the African coast, Mr. Walker commenced to 'collect zoological objects in general, a large part of which were

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