Is this the scene where Freedom's purest flame Once lovely scene! along thy mould'ring piles One little stream,—around whose bubbling head Thou Eden of the desert! lovely smild Thy matchless beauty o'er the lonely wild; 'Mid barten solitudes securely plac'd, Thy native bulwark the surrounding waste, Such were the souls that o'er the proud array Then, lovely city, what rejoicings rose Such was thy glory once! a transient gleam portals of the night; gloom of night's obscurer shades. Oh! if departed glory claims a tear, At length drew nigh th' inexorable hour Yet all undaunted stood the warrior-queen, valour failid, Art won the day, and stratagem prevaild. Thus the proud seat of science and of arms, Where was Zenobia then?-what inward pow'r On a Species of Earthy Matter spontaneously Combustible. 183 When Rome and havoc swept the sadd’ning plain, Turn from the scene of her disastrous fate, MODERN. FROM THE EDINBURGH PHILOSOPHICAL JOURNAL. a On a Species of Earthy Matter spontaneously Combustible. By John Murray, Esq. F. L. S., M. W. S., &c. &c. Communicated by the Author. As you had the goodness to insert in a former number of the Edinburgh Philosophical Journal, the results of a chemical investigation of the properties of a liquid matter which I collected in the crater of Vesuvius, I have taken the liberty of submitting a description of a peculiar species of earthy matter, dug up at Ashleyhag, in the parish of Wirkswork, Derbyshire, which is remarkable for its spontaneous combustion. I have not been able to submit it to a very minute examination, but intend to do this when at leisure, and I may then have it in my power to send you a more rigorous analysis. This remarkable earthy matter was discovered about fifteen years ago, about six feet below the surface soil, by labourers engaged in “soughing” some land, situated on a declivity nearly at the base and S.W. side of Allpont, the greatest elevation in the south of Derbyshire. The following are the strata incumbent on this substance: Surface soil, from 6 to 8 inches deep. 2 feet thick. 3 feet thick. Then proceeds, The substance referred to, 3 feet thick. Underneath this is a stratum of lapideous matter, called by the people Toadstone, (amygdaloid,) but which is a simple aggregated mass or Breccia, composed of fragmented pieces of a dark red sandstone, agglutinated by peroxide of iron. The water beneath these deposits is an ochrey sediment. This peculiar matter was immediately pronounced to be a rich and valuable soil, and consequently a considerable quantity was removed and put up into a heap near the garden wall, for the purpose of employ 1 ingit in horticulture. It had only lain in this form twelve or fourteen days, when it emitted copious rolumes of smoke, accoinpanied with a powerful sulphureous smell. The farmers, in order to extinguish it, ordered water to be thrown into the mass. This, however, only increased the evil, and, at the imminent hazard of suffocation, it was necessarily removed to a distance. A small quantity had been scattered on some meadow-land. The grass immediately irithered, and several years elapsed before it recov. ered its wonted fertility. The residue of two cart loads (after this spontaneous combustion), would not fill a wheelbarrow. The external or physical characters of this substance would induce us to believe it to be a rich dark mould. It is mingled with fragments and fibres of decayed wood, and with glistening metallic particles. It has a considerable avidity for moisture, and soon becomes humid. Dissolved in distilled water it possesses a ferruginous and styptic taste. When ignited in a platinum spoon with a spirit-lamp, it becomes light brown, with interspersed minute shining particles, apparently metallic. It glows in this flame like pyrophorus, giving off copious and sulphureous vapours. The sulphurous acid gas thus found was announced by its peculiar smell and dense smoke, when a stopper moistened with ammonia was brought near. From experiments made, its probable constituents, on the effusion of water, are carbonaceous matter, muriate of soda and magnesia, and the sulphates of lime, lead, copper, and iron. Its spontaneous ignition may be accounted for, by the united action of air and water on the sulphur, in contact with metalline and carbonaceous matter, analogous to the phenomena sometimes exhibited in the aluminous schistus at the Hurlet mine, near Paisley; or, that of a paste of sulphur and iron filings, when moistened. On the Detection of very minute quantities of Arsenic and Mercury. By James Smithson, Esq. F.R. S. (To the Editor of the Annals of Philosophy.) Sir–To be able to discover exceedingly small quantities of arsenic and mercury must, on many occasions, prove conducive to the purposes of the chemist and the mineralogist, more especially now that a very diminished scale of experiment, highly to the advantage of these sciences, is becoming daily more generally adopted. But the occasion above all others in which the power of doing this is important, are those of poisonings. In these it is often of the first moment to be able to pronounce with certainty, from portions of matter of extreme minuteness, on the existence and the nature of the poison. OF ARSENIC. I have already communicated the method here proposed for the discovery of arsenic by employing it in the analysis of the compound sulphuret of lead and arsenic from Upper Valais, printed in the An. nals of Philosophy for August, 1819, but not having mentioned the а generality of its application, or the great accuracy of it, it seems not superfluous, from the importance of the subject, to resume it. If arsenic, or any of its compounds, is fused with nitrate of potash, arseniate of potash is produced, of which the solution affords a brickred precipitate with nitrate of silver. In cases where any sensible portion of the potash of the nitre has become set free, it must be saturated with acetous acid, and the saline mixture dried and redissolved in water. So small is the quantity of arsenic required for this mode of trial, that a drop of a solution of oxide of arsenic in water, which, at a heat of 54.5o Fahr, contains not above 1-80th of oxide of arsenic, * put to nitrate of potash in the platina spoon and fused, affords a considerable quantity of arseniate of silver. Hence when no solid par , ticle of oxide of arsenic can be obtained, the presence of it may be established by infusing in water the matters which contain it. The degree in which this test is sensible is readily determined. With 5.2 grains of silver, I obtained 6.4 grains of arseniate of silver; but 0.65 grain of silver was recovered from the liquors, so that the arseniate had been furnished by 4.55 grains of silver. In a second trial 7.7 grains of silver, but of which only 6.8 grains precipitated, yielded 9.5 grains of arseniate. The mean is 140,17 from 100 of silver. 107.50 32.67 Consequently 1 of acid of arsenic will produce 4.29 of arseniate of silver; 1 of white oxide of arsenic, 4.97 ; and 1 of arsenic 6.56. OF MERCURY. All the oxides and saline compounds of mercury. laid in a drop of marine acid on gold with a bit of tin, quickly amalgamate the gold. A particle of corrosive sublimate, or a drop of a solution of it, may be thus tried. The addition of marine acid is not required in this case. Quantities of mercury may be rendered evident in this way which could not be so by any other means. This method will exhibit the mercury in cinnabar. It must be previously boiled with sulphuric acid in the platina spoon to convert it into sulphate. Cinnabar heated in solution of potash on gold amalgamates it. A most minute quantity of metallic mercury may be discovered in a powder by placing it in nitric acid on gold, drying, and adding muriatic acid and tin. A trial I made to discover mercury in common salt by the present method was not successful, owing, perhaps, to the smallness of the quantity which I employed. I am, sir, yours, &c. JAMES SMITHSON. INFLUENCE OF GREEN FRUITS UPON THE AIR. M. Theodore de Saussere has given the following as the results of his experiments on this subject : Green fruits have the same influence as leaves upon the air both in Chimie de Thenard, II. p. 167. Vol. I. No. 2.-Museum. 2 A |