Foreign Postage Stamps. 
We will buy, in any quantities, used stamps of all countries. 
GOOD PRICES PAID. 
STAHPS BOUGHT OR SOLD. 
Philatelists in foreign countries are invited to correspond. 
A, L, GASSING & CO, 
51 Portland Street, BOSTON. 
Microscopic Thin Sections of Rocks and Minerals skill- 
fully mounted, in collections containing 25 or more; also 
separate. 
The following collections ready, many with corresponding hand-specimens, and 
several with carefully prepared printed Commentaries, describing the minerals in each 
thin section. 
I. Minerals constituting rocks. VII. American Eruptive Rocks. 
II. Common American rocks. VIII. General Eruptive Rocks. 
III. Rocks of New Hampshire. IX. American Rocks (small sections). 
IV. Rocks of Europe. X. Popular Collection for Microscopists. 
V. Rocks of Germany. XI. Rocks of North Carolina. 
VI. Rocks of Eastern America. XIII. Building stones in use in United States. 
XIV. Polar iscope Collection (also suitable for lantern). 
Supplies for slicing, grinding and mounting. 
Hand specimens of rocks, in large stock and great variety. 
Lithological machines for grinding down thin sections and for slicing and polishing 
rocks and minerals. Every machine adapted to foot power or any motor. 
The best and only durable machines for lithological purposes made: references all 
over the country. 
Send for Circular to 
GUSTAVUS D. JULIEN, 
5outh=west Corner 50th Street and 4th Avenue, 
NEW YORK CITY. 
