MINERALS 



TWO NEW SPECIES. 



Lawsonite, from Tiburon Peninsula, California (silicate of lime and alumina). 

 In orthorhombic crystals of various habits and good lustre, from size suitable for 

 the microscope up to two inches in length, grouped in Margarite schist. Resem- 

 bles the pale sapphire and gray shades of Corundum or Cyanite. 



Northupite, from JBorax Lake (chloroearbonate of sodium and magnesium). A 

 new and perfectly stable compound, crystallizing in beautiful octahedrons, which 

 show an interesting internal structure. 



Opalized Wood, from Idaho. A recent discovery. It is accepted by all who 

 have examined it, as the most perfect example of petrifaction ever seen. Sections 

 of limbs three inches and upwards in diameter exhibit beautiful graining, with rings, 

 cells, and fibre of the wood replaced in minutest detail by a lustrous brown-yellow 

 opal. As with both Lawsonite and Northupite, we were fortunate enough to 

 secure the entire find and are enabled to offer choice specimens of all three at 

 very low prices. 



Also: Variscite, Crystallized Cryolite, Noselite, Diadochite, Koninckile, Richellite, 

 Axinite, Beautiful quartzoid crystals of Endlichite, and many other rare species. 



5^° Any of the above will be sent on approval. 



Illustrated Catalogue 128 pp., containing complete price lists with des- 

 cription of collections, etc.; and all circulars free. Send for our last " Sup- 

 plement " descriptive of recent important arrivals. 



SCIENTIFIC BOOKS, PAMPHLETS, PAPERS, PROCEEDINGS 

 AND TRANSACTIONS OF SOCIETIES, JOURNALS, ETC. 



An immense stock. Catalogues are published in all branches of Natural 

 and Physical Sciences, such as Geology, Mineralogy, Mining, Botany, Eth- 

 nology, Zoology, General Science, Microscopy, Physics, Electricity, Chemistry, 

 Agriculture, Education, and Medicine in all branches. 



All American books in print furnished on order, and foreign books 

 obtained within a few weeks. 



We make a specialty of Papers published in the Proceedings and Transac- 

 tions of Scientific Societies, and many of the scientific men of the country, 

 recognizing the advantage of such an exchange, have placed copies of their 

 papers in our hands for sale. With our ever-changing and constantly 

 increasing stock, we can supply old and recent literature on all scientific sub- 

 jects, and lists of books and papers referring to special subjects will be fur- 

 nished gratis on application. 



Dr. A. E. FOOTE, 



Warren M. Foote, Manager. 



1224-26-28 North Forty-ITirst Street,". 

 PHILADELPHIA, PA., U. S. A. 



Established 1876. 



