rocks of Ohio which I have undertaken, and from which I hope to derive important results relative to the origin of bitumen, both animal and vegetable, the depth under water or beneath sediments at which the process of bituminization took place and the diffusion of the bitumen in certain sediments and not in others, I think I have already found facts enough to prove that the bitumen now disseminated through our shales, &c., must once have been in a condition of fluidity somewhat akin to that of petroleum. Mr. Hunt, p. 522, speaks of the oil-producing corals of Bertie as being "surrounded by solid crystalline encrinal limestone which is free from oil," and of the "light-colored limestones above and below" as being "not only destitute of oil but impermeable to it." In these cases the petroleum appeared to be completely confined within limestone walls only to be revealed by the well or excavation. May we not ask whether, if the surroundings of this petroleum had originally been different, that is, had there been proper sediments with suitable submergence and pressure, would not the petroleum have been absorbed and helped to constitute bituminous strata? But can we follow this reasoning beyond this point, and infer that all the free petroleum distributed throughout our wide oil fields was produced at the time of the original bituminization of organic matter, and was preserved by the nature of its surroundings from being absorbed, and that subsequently more or less of this petroleum ascended from its places of birth to accumulate in such receptacles as the fissures of the third sand-rock of Oil Creek, Pa.? If such were the origin and history of all our petroleum it would be reasonable to suppose that much of it would still be found in situ, i. e., where it originated; but instead of this, all the oil I have ever seen, except very insignificant quantities in isolated cavities in fossiliferous limestones, has evidently strayed far from its place of origin. It is seldom, indeed, that we find any oil in juxtaposition with bituminous strata of any kind. It is more often found in fissures in sand-rocks, rocks in which no oil could ever have been generated, for whatever organic matter they might have contained was too much exposed to atmospheric oxygen to admit of the possibility of any bituminization. It is not only impossible that the oil could have originated in these sand-rocks, or in the arenaceous shales which underlie them in western Pennsylvania, but is most probable that the oil ascended from the still lower rocks in the form of vapor which condensed in the superior cavities. In other words, the oil which, according to the theory, was formed far below in the original bituminization of organic matter, must have undergone a process of distillation. AM. JOUR. SCI.-SECOND SERIES, VOL. XLII, No. 124.-JULY, 1866. In favor of the other theory, that petroleum, as now generally found, is the product of a distillation of bituminous shales, &c., as suggested by Dr. Newberry and others, the following arguments may be urged: 1st. Oil may be artificially produced by distilling such shales and other bituminous materials. In all essential respects, the analogy between the natural and artificial oils is complete. 2d. The phenomena of oil and gas exhibited in our oil fields greatly resemble those observed in the artificial distillation of oil from bituminous materials. These phenomena include inflammable gases, naphthas, heavy oils, asphaltums, &c. 3d. It is believed that some petroleum has been actually produced in the earth by distillation. Dr. Newberry, in an article on "Rock Oils of Ohio," thinks he finds local proof of the distillation of the petroleum in the great bituminous springs of California, from Tertiary lignites, there being evidences of recent igneous action in the region. European geologists have attributed a similar origin to the petroleums of Italy. Of course, where igneous action is intense, all the bitumen would be entirely driven off. The same would be true where the action is considerable and long continued, as in the anthracite coal region of Pennsylvania where the coal has lost its bitumen, but no oil was formed, or, if formed, it was soon dissipated in gas. 4th. There is an abundance of oil-making material in the earth. The subterranean retort is largely charged. 5th. A comparatively low temperature is believed to be adequate to set free the oil vapors. 6th. By this theory there might be produced an almost indefinite quantity of petroleum, since bituminous strata are found widely distributed. In this way the existence of petroleum in so many different geographical districts may be readily explained; whereas, by the opposing theory, we are not certain that petroleum, as such, has been produced by the direct bituminization of organic matter, except in few strata and in very insignificant quantity. Finally, the agency which would volatilize the liquid bitumen, or petroleum formed by direct bituminization, and bring it up and distribute it through the present oil horizons would certainly be adequate to distill the bituminous shales, &c., and bring up the oil to the same ele vations. It may, however, be objected, that if this theory of distillation be true, we ought somewhere to find the residuum, or debituminized shales, &c., remaining after the oil had been extracted. Such discovery could not justly be expected in surface rocks, because, according to the theory, the heat agency would at best be small and could be scarcely felt near the surface. The question, then, would be reduced to this, viz: do the borings in deep wells ever show that the deep bituminous strata have lost any of their original and normal quantity of bitumen? I will present one or two facts which may have some bearing upon this point. I am indebted to the courtesy of Mr. R. K. Randolph, superintendent of the Carlisle Oil Co., for a record of a well 860 feet deep bored by him near Petroleum, West Va. This well is near the center of the strata marked C in fig. 2. The top of the well is in the lower portion of the Coal-measures. At 170 feet below the surface, Mr. R. struck a series of sandrocks which continued 419 feet. I cannot suppose otherwise than that these sand-rocks are the geological equivalents of the Waverly sandstones of Ohio. Below these he passed through 265 feet of what the record terms a "gray shale with much soot." The position of these shales would make them the equivalents of the black shales of the Ohio Devonian formation, which in Ohio are 250 feet thick. They evidently contain some. light carbonaceous matter in the "soot," but the record calls them "gray shales," not black. Mr. R. is familiar with "black shale," for he passed through two seams of it in the first 56 feet of the well. Now have these deep shales, nearly 600 feet down and situated within the double dislocation of strata already described, lost a part of their bitumen and been changed from black to gray? Unfortunately, I have not been able to obtain any sample of the borings in this shale, they, with the "soot," having been washed away. Mr. R. is boring his well still deeper. Should he soon enter the equivalents of the Cliff limestone of the Ohio Reports, I shall then feel assured that he has already passed through the exact equivalents of the Ohio Black Shales and found them "gray." Of course, such facts are not conclusive as to any positive loss of bitumen, but they are not without significance. Should I find many similar cases where strata, which are highly bituminous at their outcrop, are found to contain little bitumen at great depths, and at the same time, the rocks above these buried strata containing in their fissures much oil, I think the inference, that the oil was derived from the bituminous shales, not unwarranted. Marietta, O., March 20, 1866. ART. V.-Notes on Japanese Alloys; by RAPHAEL PUMPELLY. THE following notes, relating to the composition of some of the many alloys in use among the Japanese, are based on information obtained from native metal-workers. In a few instances, as with the shakdo and gin shi bu ichi, the process of manufacture, generally hidden, was shown me. I. Shakdo, an interesting alloy of copper and gold, the latter metal in proportions varying between 1 p. c. and 10 p. c. Ob. jects made from this composition, after being polished, are boiled in a solution of sulphate of copper, alum and verdigris, by which they receive a beautiful bluish-black color. I can explain this color only by supposing that the superficial removal of the copper exposes a thin film of gold, and that the blue color produced. is in some manner due to the action of light on this film of gold. The intensity of the color, and to a certain extent, the color itself, are proportionate to the amount of gold, one or two per cent of this metal producing only a rich bronze color. Pure copper treated in the above solution received the appearance of an enamelled surface with a rich reddish tint, and brass a similar surface with a darker shade. Shakdo is used for a great variety of ornaments, as sword-guards, pipes, clasps, etc. II. Gin shi bu ichi ("quarter silver") is an alloy of copper and silver, in which the amount of silver varies between 30 and 50 per cent. Ornamental objects made from this composition take, when subjected to the action of the above solution, a rich gray color much liked by the Japanese. It is used for sword ornaments, pipes, and a great variety of objects. III. Mokume; several alloys and metals of different colors associated in such a manner as to produce an ornamental effect. Beautiful damask work is produced by soldering together, one over the other in alternate order, thirty or forty sheets of gold, shakdo, silver, rose copper, and gin shi bu ichi, and then cutting deep into the thick plate thus formed with conical reamers, to produce concentric circles, and making troughs of triangular section to produce parallel, straight or contorted lines. The plate is then hammered out till the holes disappear, manufactured into the desired shape, scoured with ashes, polished, and boiled in the solution already mentioned. The boiling brings out the colors of the shakdo, ginshibuichi, and rose copper. IV. Brasses (Sin chu).—The finest quality of brass is formed of 10 parts of copper and 5 of zinc. A lower quality, of 10 parts copper and 27 zine. V. Kara kane (bell-metal).-First quality-copper 10, tin 4, iron, zinc 1. Second quality-copper 10, tin 21, lead 14, zine . Third quality-copper 10, tin 3, lead 2, iron, zinc 1. In forming the bell-metals the copper is first melted and the other metals added in the order given above. The best small bells are made from the first quality. Large bells are generally made from the third quality. The kara kane has a wide range of use in Japan. Solders. For bell-metal-brass 20, copper 10, tin 15. For gin shi bu ichi-silver 10, first quality brass 5, zinc 3. For shakdo-fine shakdo 3, zinc 10. For tin-tin 10, lead 5. Among the Japanese articles made of copper that find their way to this country, there are some with a bright red surface, which is often taken to be either a lacquer or an enamel. These objects are made of copper containing red oxyd through the entire mass, and after receiving the requisite form and a high polish, are boiled in the mixture mentioned above. ART. VI.-Notes on Tides at Tahiti, and Earthquake phenomena; by Dr. C. F. WINSLOW. From a letter to one of the Editors, dated Munich, March 26, 1866. I RECEIVED the American Journal of Science for March this morning, and have read with great interest the article on the Tides at Tahiti communicated by Prof. Bache, upon the observations of Capt. J. Rodgers. When at Tahiti in 1844 I was immediately struck with the anomaly in the tidal phenomena. I observed the daily wave more or less regularly (but with the eye alone) on the shore and in certain inlets between Taunoa and Papiete, from the 14th of May to the 14th of June, the period of my stay there. Residing near the shore at Taunoa and walking daily to and from Papiete, and riding round the beach beyond point Venus, I constantly had opportunity for observation. The tide was low in the morning and highest from 12 to 2 o'clock, as a common observation. When on the reef off Taunoa, about the 10th of June, late in the afternoon (my notes are at home and I do not remember the exact day), the tide rose later and I was obliged to abandon my observations and collections on account of this unexpected circumstance. I remained on the reef until the sea swelled to a depth of eight or ten inches, as waves would strike the barrier and then flow strongly over it. My observations were never made with mathematical accuracy, but the latter fact accords with the imperfect records of the tide-guage established by Capt. Rodgers for the same month in 1858. The remark of Capt. Rodgers, that "the range of the tides seems to be considerably less near the solstice, than they are near the equinox," will be found to hold as a constant truth; for upon this point I made inquiry and requested observations to be made, which were afterwards reported to me by the late Capt. John Hall, a Boston gentleman, who was for many years a merchant at Papiete. The results of the observations are that the |