Other lines still more delicate come into view with the aid of a glass, forming a complication of patterns exceedingly delicate, but too intricate for description. They do not however possess any analogy to the etchings on meteoric iron, steel or cast-iron. The surface G at its uppermost portion (or to the right in the figure) is almost perfectly smooth, presenting only a faint resemblance to the flat side, in the presence of a few nearly obsolete wrinkles. At the middle region, however, these elevations become more strongly marked; while still lower down (to the left) they degenerate in regularity and pass into the pitted and undulous surface, as they form the interior of a crateriform cavity fully half an inch deep, by three quarters of an inch across at its opening. The appearance of this cavity at once suggests the idea that a blunt solid was thrust into the matter when nearly congealed, forcing it into the large wrinkles or waves which form the circumference of the crater. Indeed, it appears highly probable that all the undulations and crimpings, large and small, originated in the foreign body that produced this deep cavity. Very little stress however could be attached to an explanation of such various and unusual appearances as this mass presents, and I could venture upon no conjecture of its origin as a whole, more probable, than that the matter of which it is composed had flowed originally into a cavity in some earthy, refractory material, where it slowly suffered congelation, pressing with greater force perhaps against the walls of the cavity on the striated or semi-cylindric side than upon the other. In any case, it seems quite certain, that its formation occurred with entire exclusion of atmospheric air; and if a meteorite, it must have been protected by a covering of stony matter, until it reached the surface of the earth. The strangeness of external aspect was regarded as affording a certain degree of probability in favor of its meteoric origin; since all who have studied these productions attentively, have recognized in them traits, wholly inexplicable from our knowledge of merely terrestrial matter. Chemical experiments soon proved that the mass was essentially composed of iron and silicon, with an unusually high proportion of the latter element; a discovery again, that pointed with some significancy towards a meteoric origin, provided the artificial source should also be rendered improbable: for up to this moment, no mineral belonging to our earth has presented silicon combined with any other element than oxygen. I hastened to communicate my result to Dr. Duffy, from whom I received (Jan. 1, 1859) the following additional information. "I had the pleasure of receiving yesterday, your note of the 27th ult. The account you give me of the mineral I sent you is very interesting. I beg you will accept of the mass from me. It was found in the spring of 1855. There is no evidence of iron ever having been made near the place. I shall be able to send you some iron-ore from the same locality, when an opportunity occurs. The nearest place of iron manufacture is High Shoal (supposed to be twelve miles distant from where the specimen was found). Before I sent it to you, I showed it to several persons connected with this furnace; but they were all equally puzzled to make out what it was. The general conclusion arrived at being, that it was of a mineral character." As yet I have received no specimens of the iron-ore said to be found at the spot. The geology of the region however is known to be primary, it being fully within the auriferous formation. It is probable that the occurrence of iron-ore at the spot is purely accidental, as such ore is widely distributed throughout the gold region of the southern states. The supposed meteorite breaks with greater facility than caststeel, first undergoing a slight condensation, if struck with the edge or the corner of a hammer. The fractured surface is somewhat even, of an iron-grey color, and yields feeble reflections of light in rather broad irregular patches, in shape most resembling those produced on a surface of a coarse-grained dolomite. Besides the broader patches of light from large foliated individuals, are others from frequent scaly points, that are much brighter. The lustre of the exterior is much higher, and the color is lighter also, than that of the fractured surface. Both are nearly identical with those of polished platinum, though the color inclines slightly to that of graphite. The mass is not wholly without vesicular cavities; but these are very rare, and can scarcely be detected without the aid of a glass. One of them is quite round, with smooth, shining black walls, (probably enfilmed with black oxyd of iron) and another near by, which is elongate and irregular, contains a distinct particle of quartz or silica. It may be mentioned here, that several similar grains, but too minute for detection with the naked eye, were left after the solution of the other constituents of the mass in acids. It nowhere shows the remains of any coating or crust, and is equally free from evincing the slightest tendency to oxydation or tarnish; and such is the delicacy of the raised lines, punctures and sinuses of the surface, it is impossible to believe that it ever had any such investiture. The hardness is 75 on the mineralogical scale, scratching quartz quite easily, when its sharp angles are applied to rock crystal. A Sheffield cutler pronounced it harder by far, than any steel. He was unable to temper it. When suddenly heated and struck with a hammer, it flew to pieces like glass. A fractured surface was smoothed, and with some difficulty, etched with aqua regia. Its color (unlike to etched steel) was but slightly darkened; and the pattern developed was simply that of a coarse grained saccharoidal limestone, rubbed down to a surface on sandstone and then moistened. It chips off under blows from the hammer into thin scales, which are easily crushed to powder in a steel mortar. It may then be ground to an impalpable powder in an agate mortar, with greater facility than many earthy minerals of inferior hardness. The following observations, showing the remarkable passivity of this iron were next made. It is not attackable by dilute sulphuric acid. If previously reduced to powder, a very feeble action is set up, which proceeds with activity as soon as heat is applied. It does not precipitate copper from an acid solution of the cuprous sulphate. In nitric acid also, there is no action, unless the acid is concentrated and slightly warmed, when a few bubbles of binoxyd of nitrogen appear. The surface however does not become sensibly corroded. Hydrochloric acid gives rise to a coating of bubbles only; and if the mass was previously polished, its surface when washed and dried, is found to have grown a shade darker, and to have lost its metallic lustre, attended with the developement of imperfect lines of crystallization. A few grammes in the state of powder were treated with hydrochloric acid at the temperature of 80°. The extrication of hydrogen gas was gradual, unattended by any sensible production of heat. The action was considerably promoted by slight agitation. On heating to 90°, the decomposition of the hydrochloric acid was much promoted; and the gas was tested, and found to be pure hydrogen.* After some hours, a strong yellowish green solution was obtained; and a film of the same color lined the flask for some distance above the level of the liquid. The flask being left in a state of rest for some time, fell in temperature to 65°; and its contents assumed a partially gelatinized form. On the slightest agitation, its consistency was somewhat dispersed, attended by a singular decrepitation, resembling the ticking of the water-hammer, on the agitation of the fluid in Wollaston's cryophorus. This continued as often as the flask was moved, for many minutes; and was unaccompanied by any sensible extrication of gas. The occurrence of this phenomenon was verified in several repetitions of the solution, and remains at present wholly without an explanation. One portion of the solution was examined by sulphuretted. hydrogen for other metals, without their detection. Another on being cleared of the iron, was found to contain faint traces of magnesium. The main portion of the hydrochloric solution, turbid with the imperfectly suspended silica, was transferred to a filter, upon which the latter was left in a voluminous state, and possessed a dark greyish tinge, as if from the presence of traces *With strong hydrochloric acid at a lower temperature (say 65°) beautiful green tabular crystals are formed, supposed to be a hydrated double chlorid of iron and silicon. SECOND SERIES, VOL. XXVIII, No. 83.-SEPT., 1859. of carbon (possibly also of silicon). The affusion of hot water produced an instantaneous effervescence, from the extrication of hydrogen. This was continued by subsequent additions, until the acid was almost completely removed, when the hydrated silica occupied the bottom of the filter, having a somewhat lighter shade of white, and on being turned out and broken up, was found to be filled with rounded, amygdaloidal cavities. This singular action of the hot water may proceed from the subversion of a compound present, consisting of the chlorid of silicon and hydrochloric acid, its decomposition being occasioned by the washing out of an excess of hydrochloric acid (aided by heat), -the new bodies eliminated being silicic acid, hydrochloric acid and hydrogen. Thus SiCl, HC1+3HO=SiO3, 2HC1+2H. Or the effervescence may be occasioned simply by the decomposition of water (aided by heat), through the presence of free silicon. The silica was so light as to require much care while drying it in a broad platinum capsule; and just prior to its ignition, a bright glow set for an instant through its entire mass, produced by the combustion of a trace of carbon. The first determination of the proportions of the iron and silicon gave as follows: Iron, 84.00 13:57 It occurred to me at this stage of the investigation to determine, whether a compound so rich in silicon would yield a pure chlorid of silicon, if chlorine were presented to it under favorable circumstances. Accordingly, a current of dry chlorine was transmitted over the powdered mineral in a glass tube, the reaction being aided by the heat of an alcoholic lamp. Arrangements were made for condensing the product in a letter U tube, surrounded by a freezing mixture. As soon as the chlorine began to traverse the heated powder, a brilliant red glow attended by scintillations in spots, appeared in the tube for the distance of half an inch (from the end nearest the source of the chlorine); and a dense yellowish smoke was emitted for a moment, from the exit tube. The action in the tube was kept up for several minutes. It now and then burst into an explosive combustion, and dashed an orange red vapor upon the tube, which was afterwards coated red-brown by a crystalline precipitate, and wetted also by a thin liquid that could not be forced to enter the cooling apparatus. At the close of the experiment, a very small quantity of a pale yellow liquid was found in the condensing tube. In this, a few drops of water produced hydrochlo ric acid and gelatinous silica. A portion of the liquid was also |