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THE POPULAR SCIENCE MONTHLY.

Horse" tavern; Haywood County, North Carolina, has furnished specimens of corundum altered into feldspar, as well as mica; examples of corundum altered into margarite (calcium mica), cases of the alternation of corundum into fibrolite and cyanite are also mentioned. The altered minerals were more or less water-worn and rounded, while the corundum which they inclose is sharp and angular, which proves that since the great gravel deposits were formed no alteration of the corundum has taken place in these deposits.

The other interesting alterations described by Professor Genth are the alteration of orthoclase into albite, and talc into anthophyllite, and pseudomorphs of talc after magnetite. Several other investigations of mineral species follow, among them gahnite, rutile and zircon, sphalerite and prehnite, pyrophyllite, beryl, niccolite, and artificial alisonite. The author also describes the accidental formation of artificial crystals of rutile during fusion with potassium hydrogen sulphate; two crystals of octahedrite were likewise produced at the same time, and had a decided blue color.

On the Age of the Tejon Rocks of California, and the Occurrence of Ammonitic Remains in Tertiary Deposits. By Angelo Heilprin. From "Proceedings of the Academy of Natural Sciences of Philadelphia," July, 1882.

The author undertakes to settle the point in dispute between Conrad and Gabb, as to the age of the Tejon rocks, referred by the former to the Eocene series, and by the latter to the Cretaceous. A list of one hundred and twelve species is given, representing the fauna of the Tejon group with the various localities of occurrence, as claimed by Gabb, and evidence presented to show that Gabb was in error in many cases, and hence that the tables do not afford a safe criterion for the solution of the problem. The author then goes on to show that, of the seventy-seven genera represented in the Tejon group, at the very least twenty-two are more or less distinctively Tertiary, and out of these eleven are not positively known to have appeared before that geological epoch. Also that, with the exception of six or seven fragments of Ammonitidæ, there is not a single distinctively Cretaceous generic type in the entire number. He therefore concludes that the rocks of the Tejon group, despite their comprising in their contained faunas a limited number of forms from the subjacent (cretaceous) deposits, and a few undoubted representatives of the Ammonitidæ, are of Tertiary (Eocene) age.

The Eocene age of the Tejon rocks is likewise maintained by Professor Jules Marcon, who made a personal examination of the region.

Proceedings of the Davenport Academy of Natural Sciences. Vol. Ill, Part II. Davenport, Iowa: Published by the Academy. Pp. 192, with Four Plates.

The present number contains the proceedings of the Academy during 18*79 and 1880, with the president's addresses of Mrs. M. L. D. Putnam and Mr. W. H. Pratt. The numerous papers testify to the great activity of the members of the Academy in the leading departments of investigation, predominantly in archæology, to the study of which the location of the society offers excellent facilities. A very interesting paper is that of Professor G. Seyffarth on the inscriptions of the Davenport Tablets, the conclusions of which are startling for their boldness.

How to Succeed: A Series of Essays by Various Authors. Edited by the Rev. Lyman Abbott, D. D. New York: G. P. Putnam's Sons. Pp. 131. Price, 50 cents.

This is a republication of a series of papers which appeared last winter in the "Christian Union," on the general subject and its applications, headed with articles by Senators Bayard and Edmunds on "Success in Public Life," and continued with other articles, by men who have attained eminence in their various professions or arts, on the elements of success in their respective callings.

Cerebral Hyperæmia: Does it exist? A Consideration of some Views of Dr. William A. Hammond. By C. F. Buckley, B. A., M. D., formerly Superintendent of Haydock Lodge Asylum, England. New York: G. P. Putnam's Sons. Pp. 129.

The author opposes the theory which Dr. Hammond has published concerning the effects of excess or deficiency of blood in