From the immense thickness developed in central Utah, the Paleozoic series, there 30,000 feet thick, thins toward the east until as before stated, in the region of the Laramie Hills, it is compressed into 1,200 feet. From the observations of Newberry, and the later accounts of Gilbert, Powell and Marvine, it is clear that it also shallows toward the south, and the observations of the Carboniferous in California would indicate thinning in that direction. The Archæan body spoken of in western Nevada may or may not have had a continental significance. It would seem, however, from the relations of the Carboniferous in the Blue Mountains of Oregon and Bass' Range in California, that, if a continental mass, it possessed deep westward bays in which the Paleozoic sediments were deposited. It is, however, probable that the Archæan body was only a mountainous region of no very great east and west development, and that the Paleozoic sediments were deposited around it to the north and south. While as yet no non-conformity has been observed in the whole series from the base of the Cambrian up, there is in middle Nevada an evidence of shallow water and the accumulation of plant-bearing earthy coal beds in the upper part of the Wahsatch limestone. When the detailed stratigraphy to the south of our field comes to be worked out, it is possible that a local uplift will be found near the close of the deposition of the Wahsatch limestone. But otherwise throughout the whole extent we have no indication of a non-conformity. On the contrary, there seems to have been a continuous undisturbed deposition varying between siliceous and calcareous sediments in which the lines of these two types of material have been sharply drawn in a deep oceanic basin over the greater part of the area of Utah and Nevada, while toward the shallow shore in the region of the Rocky Mountains the deposit was more irregularly mixed. Aside from the intimation of a local shallowing at the close of the Wahsatch limestone in western Nevada, the evidences are all of deep-water deposits till near the close of the Upper Coalmeasure series, when ripple-marked shales make their appearance, and the Permian depositions thereafter seem all to be of a shoal-water character. ART. LXVI.—A Nebula-photometer; by E. C. PICKERING. (From a letter to the editors, dated Boston, April 5, 1876). An examination of the article in the May number of this Journal on the changes on the Nebula M. 17 shows the desirability of accurate photometric measurements of these bodies. I wish therefore to make known the following nebula-photometer in Page 482, line 5 from top, for Powell read Howell. To measure the brightness of a nevuia vic brought in succession into the center of the field and the light varied until the spot disappears. The exact position of each point is found by observing the various positions of any star in the field with regard to the squares. The real motion of the photometer is thus found from the apparent motion of the star. A contour map may then be constructed showing the brightness of the various portions, and would soon show any marked changes in the light of the various parts. The light of the adjacent sky must be similarly measured and subtracted from all the readings. The brightness may be compared with that of any star by throwing the latter out of focus until its disk attains a given size, and a star photometer is thus obtained. Observations on a comet, with contours showing its brightness on various days, would be both interesting and valuable. The brightness of different portions of the moon could be measured by slightly modifying this photometer. By using a very low power the light of an aurora, of the zodiacal light or of different portions of the sky could be similarly measured. For very faint objects it might be better to insert a diaphragm in the eye-piece having an aperture but little larger than the collodion film, thus giving a dark background. Positions could then be determined by the finder or by moving the entire eye-piece by micrometer screws. SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHYSICS. 1. On Hydrocellulose.-In some of the processes in the arts in which cellulose is used, as in paper-making, this substance undergoes a transformation by which it is rendered friable. AINIE GIRARD has investigated the matter, and finds that this change is owing to the assumption of a molecule of water by the cellulose to form a new body of the composition, C,,H,2011, to which he gives the name of hydrocellulose. To prepare it, some form of purified cellulose, such as carded cotton, is placed in sulphuric acid of 45° B. in the cold for twelve hours. It is then well washed, pressed and dried. After it is dry, its fibrous character is destroyed by pressure; rubbing between the fingers converting it into a white powder. Girard explains in this way the brittleness of certain papers bleached with chloride of lime. — C. R., lxxxi, 1105, Dec. 1875. G. F. B. 2. On the Decomposition of Stearic Acid by distillation under Pressure.-Under the direction of Professor Thorpe, JOHNSTON has submitted stearic acid to distillation under pressure, with a view to determine the decomposition products. A copper tube was employed for this purpose, bent twice at right angles. At the second bend from the end, which served as the retort, was an elongation of the tube serving as a receiver. The end of the tube was provided with a stopcock to allow the gases to escape. The stearic acid was heated, allowed to distill over, then run back into the retort, again distilled over, and so on until the acid was completely decomposed. The liquid products were collected and examined. They proved to be hydrocarbons of the marsh gas and olefine series exclusively. The gases resulting were similar, with the addition of water vapor and carbon dioxide.-J. Chem. Soc., II, xiv, 8, Jan., 1876. G. F. B. 3. On Liquid Carbon Dioxide in mineral cavities. heating a microscopic slide of quartz containing fluid cavities only to a moderate temperature, HARTLEY was surprised to find that the liquid, previously perfectly visible under the microscope, had disappeared. On cooling, the liquid reappeared accompanied by a sort of flickering movement within the cavity. Experiments on fluid cavities in various minerals made by Brewster in 1823, showed that the liquids all disappeared below 88° F., that their expansion between 50° and 80° F. was 32 times that of water, and their index of refraction 1.2946 in topaz and 1.2106 in amethyst. From these results Simmler, and later, Sorby and Butler concluded that the liquid must be carbon dioxide. The author sought carefully to determine the critical point of the liquid, which he did by immersing the slide in water of known temperature, removing, wiping hastily, and examining. As a result, it appeared that the critical point lay between 30.75° and 31° C., that point for pure carbon dioxide having been fixed by Andrews at 30 92° C. In further corroboration of this view is the fact that when water was also present in the same cavity, the other liquid floated on it; the density of carbon dioxide being 0.83 at 0° and 0'6 at 30°. Moreover, Geissler has shown the presence of this gas in quartz by its spectrum in a vacuum tube in which the quartz was broken. In explanation of the formation of these fluid cavities, the author supposes the silica in hot solution to have come in contact with a limestone under pressure, setting free carbon dioxide which being enclosed in the crystal cavities along with water would on cooling condense to a liquid.-J. Chem. Soc., xxix, 137, February, 1876. G. F. B. 4. Decomposition of Alcohol by Aluminum and its Iodide.GLADSTONE and TRIBE have continued their researches on the action of aluminum in presence of its haloid salts upon organic bodies. Alcohol for example, which may be boiled for hours with metallic aluminum without action, evolves hydrogen at once when aluminum iodide is added to the mixture, and in amonnt precisely equal to that theoretically obtainable from the aluminum. The residue of the reaction consisted of aluminum ethylate mixed with some iodo-ethylate. The former body distilled over above 275° C., but suffered partial decomposition. Under diminished pressure, a yellowish white solid collected in the receiver, which fused at 115° and boiled about the boiling point of mercury. Analysis showed it to be aluminum ethylate. The same action was observed with amyl alcohol, and with bromide in place of iodide.-J. Chem. Soc., clviii, 158, Feb., 1876. G. F. B. 5. New Method for producing Condensed Hydrocarbons.WATSON SMITH, having observed that naphthalene passed through a red hot tube, loses hydrogen and produces iso-dinaphthyl, sought to increase the yield of this substance by heating the naphthalene vapor with that of some volatile and easily reducible metallic chloride, the chlorine of which should help to remove the hydrogen. A mixture of naphthalene and antimonous chloride vapors passed through a red hot tube filled with pumice, gave an abundant yield of iso-dinaphthyl. The reaction is— The author thinks the reaction general.-Ber. Berl. Chem. Ges., ix, 467, April, 1876. G. F. B. 6. On Manganese Boride and on the Function of Manganese in Iron Metallurgy.-TROOST and HAUTEFEUILLE have produced a definite manganese boride simply by heating boric acid in a carbon crucible with manganese carbide. Small dark violet crystals were obtained which afforded on analysis the formula MnBo, containing 27 per cent of boron. When free from an excess of manganese, it dissolves in acids, disengaging hydrogen. Water is not decomposed by it at 100°. Mercuric chloride when moist transforms it at once into manganese chloride, boric, and chlorhydric acids. In this reaction, each gram evolves 1697 calories; while its elements taken free evolve 4184; the difference 2487 calories represents the heat set free by the manganese and the boron in combining. Hence the compound is an energetic one. Iron borides too are stable, unlike the iron carbides and silicides. The authors conclude from their researches that the important part which manganese plays in the metallurgy of iron is due (1) to the formation of compounds which evolve in their production a greater amount of heat than that set free by the corresponding compounds of iron; and (2) to the facility with which these compounds form slags, since in oxidizing they evolve more heat than those which contain the same quantity of iron; especially when, as is the case, they exist in presence of a large excess of metal.— C. R., lxxxi, 1263, Dec., 1875. G. F. B. To obtain 7. On the Occurrence of Platinum, Palladium, and Selenium in Silver coins.-In a letter to Wöhler, RÖSSLER, of the Frankfort parting office, gives some facts of interest relative to the work done in that establishment. During the last year over 400,000 pounds of silver and 5,000 pounds of gold were parted. The silver is purified by crystallization as sulphate and subsequent reduction to the metallic state by iron turnings. The gold is precip itated from its solution in aqua regia by ferrous chloride and melted in gas furnaces; being obtained 1000 fine in this way. Fine silver, especially that obtained from old coins, contains gold averaging about one-thousandth. It also contains both platinum and palladium, the latter sometimes in so large a quantity that its solution in nitric acid is dark yellow. The silver from Commern and Mechernich in the Eifel showed 0.0058 per cent platinum and 0.0053 per cent palladium. In the last year, the office has obtained from the 500,000 pounds of crude silver worked over, twelve pounds of platinum and two pounds of palladium. these metals, the solution, from which the gold has been precipitated by ferrous chloride, is reduced again by iron turnings, whereby all the other metals present are precipitated as a black sediment. This is freed from copper by the iron chloride, the residue is dissolved in aqua regia, the traces of remaining gold are removed, the platinum is thrown down by ammonium chloride and the palladium by ammonia and hydrochloric acid. In this way selenium was discovered in this deposit. Since then the sediment is fused with soda and charcoal before treating it with aqua regia; several pounds of selenium a year being obtained from this source. The selenium forms an interesting compound with palladium, which is obtained in hard brilliant plates when the regulus obtained as above is dissolved. These plates are not soluble in nitric acid, nor, when platinum is present, in aqua regia; but on ignition they evolve selenium and are then soluble. They are composed of equal atoms of palladium and selenium and resemble the iridosmine scales very closely, being isomorphous with them.-Liebig's Ann., clxxx, 240, Feb., 1876. G. F. B. 8. On the Conversion of Olefines into the corresponding Alco hols.-The considerable similarity between the heptylene obtained from pentamethyl-ethol and the terpenes led BOUTLEROW to attempt the direct synthesis of the alcohol from the olefine by direct union with water, just as the hydrate of terpin is formed. The heptylene was sealed in a tube with water containing a little nitric acid and alcohol. After a few weeks the heptylene had disappeared and had been replaced by the characteristic crystals of pentamethyl-ethol. Liquid isobutylene was then subjected to a similar treatment and with a similar result; trimethyl-carbinol was produced. Sulphuric acid was found to act upon isobutylene in the same way. This olefine, sealed in a tube with double its volume of a mixture of equal parts concentrated sulphuric acid and water, disappeared in the course of two days, and yielded |