Made to fill the need of the chemists for dependable piece of apparatus at a reasonable price. This Oven was the pioneer in this class of apparatus and still maintains its position as the lowest priced satisfactory constant temperature drying oven. It will produce any desired temperature between room temperature and 200°C. A workman-like piece devoid of the cast of ornamentation. Made for 110-volt or 220-volt currents, operates on alternating or direct current. Furnished complete with thermometer, cord and plug for attaching to lamp socket. PRICE, $35.00 Descriptive circular on application. E. H. SARGENT & CO. AND CHEMICAL APPARATUS OF High GRADE ONLY 155-165 EAST SUPERIOR STREET CHICAGO, ILL. As Good as the Catalog Describes Them Kewaunee Aquarium, No. 1020. Very handsome and exceptionally well built Truth in advertising demands that the printed word shall not even exaggerate the article described, although many manufacturers still hold that a little “poetic license” in description is permissible in business. Kewaunee Laboratory Furniture The Kewannee Book, like Kewaunee Furniture, is straight realism. There is no veneer on either. A letter from a discriminating School Executive says that "it gives one pleasure to find that the articles ordered are as good as the Catalog describes them." The Kewaunee Book will interest Superintendents and Teachers who are thinking of installing Laboratory Equipment for Physics, Chemistry, Biology, Agriculture, Electricity, Domestic Science or Art, Manual Training or the Kindergarten. Ask for a copy, indicating the subject in which you are interested. Address all inquiries to the factory at Kewaunee. Branch Offices Kewaunee Sand Table, No. 2103. A necessity in every Kindergarten Department No Laboratory Equipment is complete without some variable resistances. To maintain the high standard of your outfit we suggest the addition of some “Becbro” Sliding Contact Rheostats (Tubular and Stone Types) Thousands of these rheostats have been manufactured and sold by us (the original American Manufacturers) to most all Universities, Colleges, Technical Schools and Industrial Concerns and have always given entire satisfaction. Write for Bulletin C-5 Philadelphia, Pa. H-ION DETERMINATIONS SIMPLIFIED The new Acree Apparatus with Pyrovolter Potentiometer is a unit outfit (not assembled), offering greater convenience and higher accuracy than any heretofore available. Even from a cost standpoint, it is worthy of your close investigation, Ask us for our New Price List of Apparatus for PA Measurements, requesting CS-18 Pyrolectric Instrument Co. 636-640 East State Street TRENTON, N. J. Grahame Chemical Company 100 Rockingham Street Natural History Material ZOOLOGY MINERALOGY We have been handling Natural History Material of all kinds for the past fifty years, and so have accumulated a very complete stock. Our prices are as low as the quality of the specimens will permit. We are constantly preparing circulars and price lists covering our material in the different branches, which we will be pleased to send free of charge to the readers of Science. Some of our recent circulars: S-121 Rare Bird Skins S-119 Cretaceous Fossils CONCHOLOGY GEOLOGY "A Calm" by J. M. Turner (1775-1851) Turner was a consistent user of Whatman Drawing Papers A Filter Paper Sponsored by 50 Years of Mastery A Ward's Natural Science Establishment College Ave. Rochester, N. Y. Naturalists' Supplies LL the consummate skill that for a century and a half has made Whatman Drawing Paper the choice of worldfamed artists has entered into the manufacture of Whatman Filter Papers. The ancient Whatman ideals are maintained in this product-comparatively new in its field, perhaps, but with the proven merit of 150 years of papermaking mastery behind it. We carry a stock for prompt delivery I. Collecting Utensils. Animals. V. Magnifiers, Microscopes and Accessories. X. Aquaria. K-S Museum Cabinets of Glass and Metal of charge upon application A comparative test will speedily prove its excellence. Make one! We will be glad to furnish samples on request. All dealers in laboratory supplies carry these papers in stock. 1 THE KNY-SCHEERER CORPORATION H. REEVE ANGEL & CO. 7-11 Spruce St., NEW YORK, N. Y. Sole Mill Representative for the U. S. A. Canada and Mexico NEW SERIES FRIDAY, FEBRUARY 11, 192 SINGLE COPIES, 15 CTS. Stanford University, Calle. Recent Blakistor Books GORDON-French-English Medic Dictionary A reference volume that has long been needed WILDER—A Laboratory Manual of Anthro pometry. Forty-three illustrations. Cloth, $3.00 postpaid. COPAUX-LEFFMANN-Introduction to General Chemistry x+195 Pages. Cloth, $2.00 postpaid. I 2mo. SMITH—Priestley in America Activities in America of the man whom chemists everywhere revere- the discoverer of oxygen P. Blakiston's Son & Co., Publishers, Philadelphia |