iv 



SCIENCE.— ADVERTISEMENTS. 



NOTABLE IMPROVEMENTS 



In 



PROJECTION APPARATUS 



The New Refleetlne Lantern attachable to any Projec- 

 tion Lantern or Stereopticon, for Bhowing upon the screen 

 prints, photos, enjjravings, sketches, diagrams, (lowers, 

 Kntonioloaiial and Anatomical Specimens, etc., all in 

 natural colors. Cuts in books may be shown without in- 

 jury (o the book. 



The Now Projeotlnjr Microscope attachabletoany Pro- 

 jection Lanlern or Stereopticon. Projection eye piece. Jle- 

 diascope for showing large microspecimensanacoolingce 11. 



The \ew Projection Spectroscopes and Polarlaoopes 

 attachable to any Projection Lantern. 



I>untern Slides to illustrate F:ducational and Scientific 

 Sulijects. We rent slides at low rates. Send lor lists, 

 naming particular subject of interest. 



WILLIAMS, BROWN «fc EARLE, 

 Manufacturers of Stereopticons, Microscopes, etc. 

 Department M. 918 Chestnut St., Philadelphia 



JDLIEN'S IMPROVED LAPIDARY LATHES 



For SLICING and POLISHING rocks, minerals, fossils, 

 etc., and for GRINDING DOWN the same into micro- 

 scopical thin sections. Lathes, fitted to foot or power, con- 

 tain COMPLETE APPARATUS for the work. Send for 

 illustrated catalogue. Rock sections for sale. 



6USTAVUS D. JULIEN, 932 Bloomfield St.. HOBOKEN, N. J. 



MARINE BIOLOGICAL LABORATORY 



Supply Department — 1. Zoology — Preserved Material 



of all types of animals for class work or for the museum. 

 2. Botany — Preserved Material of Algae, Fungi, Liver- 

 worts and Mosses. For price lists and all information ad- 

 dress GEO. M. GRAY, Curator Woods HoU, Mass. 



Ninth Revised Edition. Published Jan. 1901,. 



The Microscope and Microscopical Methods 



By SIMON HENRY QAQE, o( Cornell University. 



Important changes have been made and the chapter on 

 Projection Microscope rewritten and more fully illustrated. 

 New figures of American microscopes and apparatus. 

 Postpaid $1.50 as for the 8th edition 



COMSTOCK PUBLISHING CO., Ithaca, N. Y. 



Dr. HOWARD ADY, M.A., Ph.D., F.R.P.S.E., M.M.S., 

 Etc., presents his compliments to Scientific men in U.S.A., 

 and says that he will supply specimens of British rocks and 

 rock-sections for microscope, with or without full petro- 

 praphical notes at eighteen pence each (English money) post 

 free. Exchanges of JSritisli /or American Minerals and Rorks En- 

 couraged, lessons by Correspondence in Lithologu a Specialty. 



11 Aspenlea Road, Hamitiersmith, London, W., England. 



THE SCHOOL OF HEDICINE 

 AND DENTAL DEPARTMENT 



OF 



GEORGETOWN UNIVERSITY, 



in the City of Washington. 



students are required to devote their entire time to the 

 study of medicine. Evening classes have been abolished, as 

 it was found impracticable to properly train men engaged 

 in other pursuits during the day. The fifty-fifth session 

 will begin September 29, 19(H, and continue for eight 

 months. 



A large corps of teachers in proportion to the number 

 of students makes instruction more directly personal and 

 adapted to the special needs of the individual. The clinical 

 facilities of the University Hospital and other city and 

 government hospitals are ample, and the laboratories are all 

 well equipped. 



Special attention is invited to the educational advan- 

 tages of tt{ National Capital, with its unrivalled libraries, 

 the Aimy Medical Museum, the Museum of Hygiene, and the 

 various scientific laboratories which are open to students. 



A circular of information giving full details of requisites 

 for admission, etc., will be sent on application to 



GEORGE M. KOBER, Dean, 



1600 T Street, N. W., Washington, D. C. 



The Journal of 

 Experimental Medicine 



Edited by SIMON FLEXNER, M.D. 

 and EUGENE L. OPIE, M.D. 



Published under the auspices of the Rockefeller Insti- 

 tute for Medical Research, New York. 



Issued bi-monthly, six numbers to constitute a volume 

 which will contain not less than 600 pages. 



Sabscription Price, $5.00 per Volume 



THE MACMILLAN COMPANY 



NEW YORK 



Macmillan & Co., Ltd., London 



Gustavus Fock, Leipzig 



Masson & Cie, Paris 



Duty Free Importations of Physiological Apparatus 

 from Standard European Makers 



Cambridge ScientiSc Inst. Co. Chas. Verdin, Max Rinck 



JS. Zimniermann F. Riinne Carl Diedericbs 



W. PetZOld R. Rothe and many others 



MAKERS' CATALOGUES WITH DUTY FREE RATES UPON REQUEST 



ARTHUR H. THOMAS COMPANY, importers and Dealers 



Microscopes and Laboratory Apparatus 



12th and Walnut Sts., PHILADELPHIA 



