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THE POPULAR SCIENCE MONTHLY 



Horse" tavern; Haywood County, North 

 Carolina, has furnished specimens of co- 

 rundum altered into feldspar, as well as 

 mica ; examples of corundum altered into 

 margarite (calcium mica), cases of the alter- 

 ation 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 de- 

 scribed by Professor Genth are the altera- 

 tion of orthoclase into albite, and talc into 

 anthophyllite, and pseudomorphs of talc 

 after magnetite. Several other investiga- 

 tions of mineral species follow, among them 

 gahnite, rutile and zircon, sphalerite and 

 prehnite, pyrophyllite, beryl, niccolite, and 

 artificial alisonite. The author also de- 

 scribes the accidental formation of artificial 

 crystals of rutile during fusion with potas- 

 sium 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 op Cali- 

 fornia, and the Occurrence of Am- 

 monitic Remains in Tertiary Deposits. 

 By Angelo Heilprin. From " Proceed- 

 ings 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, repre- 

 senting 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 prob- 

 lem. 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 Ammonitidm, 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 Ammoni- 

 lidce, are of Tertiary (Eocene) age. 



The Eocene age of the Tejon rocks is 

 likewise maintained by Professor Jules Mar- 

 con, 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 pro- 

 ceedings 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 lead- 

 ing departments of investigation, predomi- 

 nantly in archaeology, 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 inscrip- 

 tions of the Davenport Tablets, the con- 

 clusions of which are startling for their 

 boldness. 



How to Succeed : A Series of Essays by 

 Various Authors. Edited by the Rev. 

 Lyman Adbott, 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 ar- 

 ticles, by men who have attained eminence in 

 their various professions or arts, on the ele- 

 ments of success in their respective callings. 



Cerebral Hyperemia : Does it exist ? A 

 Consideration of some Views of Dr. 

 William A. Hammond. By C. F. Buck- 

 ley, B. A., M. D., formerly Superintend- 

 ent of Haydock Lodge Asylum, Eng- 

 land. 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 



