via OBITUARY NOTICES. 



anonymously in an amateur journal,^ and in 1888 an admirable ac- 

 count of the " Modes of Occurrence of Pyrite in Bituminous Coal,"' 

 prepared while engaged on the State Survey. In this he recognized 

 five forms of occurrence and traced the origin of the pyrite to the 

 iron content of decomposing plants affected by the sulphur from 

 gypsum or hydrogen sulphide. Nodular pyrite he suggested was 

 formed from fish remains in the same way ; while attention is called 

 to the present-day formation of pyrite in the scum seen on stagnant 

 pools. In 1894 he published " A Comparative Study of the 

 Chemical Behavior of Pyrite and Marcasite,"* which was his thesis 

 for the degree of Doctor of Philosophy. This is distinctly a piece 

 of chemical research, dealing with the relative oxidation of sulphur 

 in these two mineral forms of FeS2, by various solutions, as well as 

 the solubility of the iron in various acids. There were two short 

 papers^ in 1891 and 1892 in which the early spiral form of Baculites 

 is described for the first time, the former of which was reprinted 

 in scientific journals both of this country'' and in London.'^ He pub- 

 lished the first definite account of the crystallization of molybdenite 

 in 1896^ and in 1898 a scholarly account" of " Jade and Other Green 

 Stones," which was a summary of a lecture given at the Museum 

 of Science and Art of the University of Pennsylvania. There were 

 several short notes on microscopical" and geologicaP^ subjects pub- 

 lished in 1896 and 1897 ^"^ ^^''^ notes in Lyman's report^* and in 

 Cope's paper^^ already referred to. In 1901 he also brought out a 

 new edition of Erni's well-known textbook, " Mineralogy Simpli- 



"^The Amateur Naturalist, III., No. i. 



3 Trans. Amer. Inst. Mining Eng., 1888, pp. 539^546. 



4 Proc. Amer. Philos. Soc, XXXIII., 1894, 225-243. 



^ Proc. Acad. Nat. Sci. Phila., 1891, pp. 159-160, and 1892, pp. 136-141. 



6 The Nautilus, V., 1891-1892, pp. 19-21. 



'^ The Geological Magazine (London), July, 1891. 



^ Proc. Acad. Nat. Sci. Phila., 1896, pp. 210-211. 



9 Bull. Mus. Sci. and Art, Univ. of Penn., I., No. 3, pp. I40-I45» April, 1898. 



10 "Bog Moss Leaves," Amer. Monthly Microscop. Jour., XVIII.. 1897. 

 232. 



11 " Red Color of Certain Formations," Amer. Geologist, XVII., 1896, 

 p. 262. " Section of Chalcedony," Amer. Monthly Microscop. Jour., XVIII. , 

 1897, pp. 235-235. 



12 " Report on the New Red of Bucks and Montgomery Counties," Final 

 Kept. Penna. State Geological Survey, Vol. III., Pt. II., pp. 2589-2638, 1895. 



13 Proc. Acad. Nat. Sci. Phila., 1894, pp. 63-68. 



