tailed and accurately measured record of any oil-well in the United States. The oil-producing sand (sandstone) belongs to the Chemung period, or the upper part of No. VIII. in Pennsylvania geology. A letter to the editors from Mr. Ashburner contains the following statements respecting it. One object in view was to determine the exact stratigraphical relations between the "Third oil-sand" along Oil Creek, Venango Co., and the producing oil-sand at Bradford. Mr. Carll ascertained, in 1875, that the two were different, and that the former was stratigraphically several hundred feet above the latter. In his Report of Progress, the top of the Oil Creek "Third sand" is stated to be about 750 feet below the bottom of the Second Mountain sand, which is probably the equivalent of the Olean conglomerate in my records. The Bradford producing sand is 1,780 feet, more or less, below this latter horizon, so that if the measures neither increase nor diminish in thickness between Bradford and Oil City, the Bradford producing sand would be about 1,000 feet below the "Third sand" along Oil Creek. We are sure that the rocks maintain a constant thickness between these two points.

The paper of Mr. Ashburner gives the records also of the Kinzua Well, 1,768 feet deep; the Wilcox Well, No. 2, or Schultz Gas Well, 2,004 feet deep; the Wilcox Well, No. 3, 1,808 feet deep; the Ernhout and Taylor Wells, Nos. 1 and 2, the latter 2,000 feet deep; the Bear Creek Well, 1,998 feet; the Silver Creek Well, 1,760 feet.

It states, concerning the Schultz Gas Well, that gas issued in immense quantities from a depth of 1,776 feet. An inch pipe was inserted to a depth of 2,000 feet, and the mouth of the well closed with the hope of causing the gas to force out the oil from the latter depth. Two or three barrels of oil were thus obtained; and if, as Mr. Schultz believes, the tube was entirely filled with the oil, the pressure of the gas was sufficient to raise a column of oil an inch square in section and 2,000 feet high. This great pressure was sustained but for a few moments; the gas probably became thoroughly mixed up with the oil, which from its low temperature quickly congealed and effectually choked the pipe." After a few hours the gas ceased entirely; but after thirty-six hours, it commenced to flow again with great energy. There was a sudden increase of the pressure in the early part of 1877. Four months later the flow of gas ceased, but in July 14th it began again to flow; and "up to the present time the amount of gas increases and diminishes at irregular intervals." The gas was used in drilling the Wilcox Well, No. 3.

2. Region of the Great Lakes.-Mr. GEORGE MAW, F.L.S., mentions (Geol. Mag., Oct., 1878) facts connected with the level and depth of the Great Lakes, and of glacial phenomena about them, (stating, among other things, that the bottom of Lake Ontario is 365 feet below the sea-level and 600 feet below its own outlet into the St. Lawrence; of Erie, 462 feet above the same; of Huron, 145 feet above; of Lake Superior, 65 feet below the

sea-level); and concludes that the idea of the excavation of Ontario to a depth of 600 feet by glacier action is wholly untenable, and that the theory of glacial excavation for the chain of large lakes must be set aside, in which he is plainly right; and he concludes that the lake depressions are of post-glacial origin.

3. On the occurrence in North America of rare Extinct Vertebrates found fragmentarily in England.--Professor R. OWEN has a paper with this title in the Annals and Magazine of Natural History for September, 1878. It treats first of the "Restoration of Chondrosteosaurus," to which he refers Cope's Camarosaurus, and secondly of the Restoration of Coryphodon. In the remarks on the latter genus, first established by Professor Owen, the author brings out many points of interest, and gives credit to Professor Marsh's discoveries for the chief part of the facts upon which they are based. The paper has the following concluding sentence. "To the close and careful comparisons of the conscientious palæontologist of Yale College, we are indebted for the above interesting and unexpected additions to our knowledge of the rare and ancient Tertiary mammal, fragmentarily indicated in the plastic clay' of England (1845) and in the conglomérate de l'argile plastique' at Mendon, France (Hébert, 1856), of the elements toward a restoration of which we might have long remained in doubt had they continued to be made known to us as parts of a Bathmodon or Loxolophodon."

4. On the Erupted Rocks of Colorado; by J. M. ENDLICH. 572 pp., 8vo. From the 10th Annual Report of the United States Geological Survey under Dr. F. V. Hayden, United States Geologist-in-charge.-Mr. Endlich classifies and describes the eruptive rocks of Colorado, their relation to the veins of ore, their age and origin.

5. Analyses of Suussurites.-The following are the references for the analyses cited on page 341.-1. T. S. HUNT, this Journal, II, xxvii, 345, 1859; 2, FIKENSCHER, J. pr. Chem., lxxxix, 456, 1863; 3, HÜTLIN & PFAFFIUS, Verh. Ġes. Freib. im Br., ii, 1861; 4, DELESSE, Bull. Soc. Geol. de France, II, vi, 547, 1849; 5, of a specimen from Neurode, Silesia, VOM RATH, Pogg. Ann., xcv, 555, 1855; 6, C. F. CHANDLER, Inaug. Dissert. Gött., 1856 (from Zobten, Silesia); 7, 8, of a lavender-blue variety, in euphotide of the Isle of Unst, M. FOSTER HEDDLE, Min. Mag., Truro and London, April, 1878; 9, DELESSE, Ann. d. Mines, IV, xvii, 116, 1850; -10, DAMOUR, C. Rend., lvi, 861, 1863; 11, L. R. FELLENBERG, Nat. Ges. Bern., 1865, 112; 12, of a saussurite hatchet from near Gerlafingen on Bieler See, Switzerland, Fellenberg, Verh. d. Schweiz. Ges. Solothurn, 1870 (G. 3.2978).

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2

The analysis of the Orezza saussurite by Boulanger appeared in the Ann. des Mines, III, viii, 159, 1835; he obtained SiO43.6, A10, 320, MgO 24, CaO 210, K2O 16=1006. He also analyzed a saussurite from Mt. Genèvre, obtaining SiO 446, AlO, 304, MgO 25, CaO 155, Na,O 75-100-6, showing an approximation to Delesse's results and a composition near that of

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labradorite; but G.-2.65; it was therefore in the feldspar, and not the saussurite, state. The occurrence of labradorite and saussurite in a euphotide, and transitions from one to the other, appear to be not uncommon.

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An analysis of a saussurite from euphotide in Norway near Bergen, afforded Th. Hjortdahl (Nyt. Mag. Nat. Christiania, and Groth's Zeitschr., 1878, 305), SiO, 42.91, AlO, 31.98, FeO 0:19, MgO 0.81, CaO 20.94, Na,O 232, K2O 0·18-99-33, with G.-3.19. It differs little from other analyses of saussurite of the first kind, or true saussurite, excepting in the small amount of magnesia.

Although jadeite is not yet known to be one of the euphotide minerals, the specimens being thus far only polished implements or ornaments, its analyses are of interest in this connection, and the following are here added:

Nos. 1 and 2 are by Damour, C. Rend., Ixi, 1865, p. 361; 3, by Fellenberg, Verh. d. schweiz. Ges. Solothurn, 1870; 4, Eckstein, in H. Fischer's work entitled "Nephrit und Jadeit," Stuttgart, 1875, p. 375.

Th. de Saussure's paper in which he gave the name Saussurite to the "Jade" which his father had described (in his Voyages dans les Alpes, i, §112 and v, §1313) is contained in the Journales des Mines, xix, 206, 1806. Further study will probably result in dividing up euphotide according to the kind of saussurite present.

J. D. D.

6. On Leucoxene in the New Hampshire Diorites; by G. W. HAWES. (From Mr. G. W. Hawes's Report on the Mineralogy and Lithology of New Hampshire.)-In this Journal, volume xii, at page 134, I described certain reticulated appearances in the "Greenstones" of New Hampshire, as probably of organic origin. These forms were the result of a species of decomposition to which titanic iron is peculiarly subject, and the structure was produced by the cleavage or lamination of the mineral. The product of the decomposition is a grayish white substance, the composition of which is not well established. It was called leucoxene by Gümbel. Sandberger and von Lasaulx regard it as a lime titanate, which results from a reaction between the titanic acid and the lime of the hornblende and feldspars. Cohen suggests that it is pure titanic acid, which view is favored by Rosenbusch. But whatever the substance may be proved to be, the forms observed are the result of the decomposition of titanic acid.

7. The association of Pyroxene and Hornblende; by G. W. HAWES. (From Mr. G. W. Hawes's Report on the Mineralogy and Lithology of New Hampshire.)--Though any material capable of forming pyroxene may, under other circumstances, crystallize in the form of hornblende, yet when the two species are so associated as to indicate their formation under the same circumstances, chemical composition must determine the species. This intimate association of the two minerals is frequent in certain eruptive rocks, and some New Hampshire diorites furnish very marked examples in which both species are well crystallized.

The following analyses of associated pyroxene and hornblende from Edenville, N. Y., at which place material in a state of purity can be obtained for analysis, were made for the purpose of discovering what chemical differences had affected the crystallization. The following were the results:

The association of pyroxene and hornblende has been noticed by vom Rath in the Vesuvian lavas, where they were formed by sublimation. (See Pogg. Ann. Band Ergänzung, vi, 229.) The analyses were imperfect on account of the small amount of material, but it is interesting to observe that they show the same differences; that is, the hornblende contains a larger percentage of alumina, a smaller of lime, and some alkali which is absent in the pyroxene. 8. Die Mineraliensammlung der Kaiser- Wilhems-Universität Strassburg, ein Supplement zu den vorhandenen mineralogischen Handbüchern von P. GROTH. 271 pp. 4to, with six plates. Strassburg, 1878 (Karl J. Trübner).-Professor Groth, during his six years' connection with the University at Strassburg, has succeeded in bringing together a mineralogical collection which ranks very high both as regards the number of specimens and their individual excellence. The catalogue which he has recently published contains the results of a very minute study of the collection, giving a description of each specimen with its locality and a determination of the form when crystallized. The work contains much that is new and valuable, and in some cases, as for instance manganite, the description is in fact a monograph of the species giving, many new planes with a large number of figures. The volume is thus a valuable contribution to mineralogical literature. E. S. D.

9. Mineralogische und Petrographische Mittheilungen, herausgegeben von G. TSCHERMAK. New series, vol. i, Vienna, 1878.The "Mineralogische Mittheilungen," which, under the editorship of Professor Tschermak, have appeared since 1871 in connection with the publications of the Austrian "Geologische Reichsanstalt, have occupied an important place among mineralogical publications. With the present year a new series has been commenced, and in future the Journal will be published independently in yearly volumes of six numbers each. Its scope is at the same time enlarged both as regards original articles, and in the summary given of mineralogical work published elsewhere, which forms an important part of each number. Its usefulness will be much increased by the change.

E. S. D.

10. Brief notices of some recently described minerals :Friseite. Occurs in dark-brown orthorhombic crystals with perfect basal cleavage; translucent and sectile. II. 2-3, G.=4.217. An analysis gave S 374, Ag 29′1, Fe 33'0-99-5, for which the formula Ag. Fe, 3S2 is obtained. It is very closely related to sternbergite both in crystalline form and in composition, and the propriety of giving it a new name may well be questioned. Locality, Joachimsthal in Bohemia.-(Vrba, Zeitschrift für Krystallographie, ii, 153).

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Hibbertite. Occurs as a loose powder of a lemon yellow color imbedded in purple kammererite. The percentage composition obtained for it after the deduction of the kammererite, from which it could not be entirely separated, is as follows:-CaO 28-46, MgO 26 55, FeO 3.23, MnO 0.58, CO, 25 44, H2O 15.73. The name is given only provisionally, as the character of the mineral is not yet established. Locality, Island of Unst (Shetland Isles).—(Heddle, Mineralogical Magazine, ii, 24).

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Hullite. A soft velvet-black mineral, with a dull waxy luster. It occurs filling cavities in the basalt of Carnmoney Hill, near Belfast, Ireland. An analysis afforded:-SiO, 39:43, AlO, 10:35, FeO, 2072, FeO 369, MgO 747, CaO 448, H,O 1861, CO2, MnO, tr. 99-77. It seems to be allied to delessite.-(Hardman, Nature, Sept. 5, 1878).

Stützite. Observed in lead-gray highly modified crystals on a specimen of gold from Transylvania (probably Nagyag). The crystals are referred to the monoclinic system, though the symmetry is closely that of the hexagonal system. Contains tellurium and a high percentage of silver, the composition being probably expressed by the formula Ag,Te-tellurium 22.5, silver 77.5. The crystalline form is closely related to that of dyscrasite and chalcocite. (Schrauf, Zeitschrift für Krystallographie, ii, 245.)

Pseudobrookite. Occurs in minute tabular crystals belonging to the orthorhombic system; cleavage brachydiagonal distinct. H. 6. G. 4'98. Color dark-brown to iron-black, but in the thinnest crystals brown to red, translucent. Luster adamantine. An analysis afforded TiO2 52·74, FeO (AlО, tr.) 42-29, CaO and MgO 4-28, ignition 0.70; according to this the mineral has the

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