SCIENCE— ADVERTISEMENTS 



SOME RECENT PUBLICATIONS 



We are issning from time to time special pamphlets in format, ariangement and typography nni- 

 form -vrith our new general apparatus catalogue now in preparation. The most recent ot these are 

 as follows : 



ANALYTICAL BALANCES of German, Dutch and American Manufacture. 



PREPARATION JARS especially selected for Laboratories and Museums of Anatomy. Pathology. Zoology 

 Botany, etc. 



STOKES AUTOMATIC WATER STILLS. 



ZEISS MICROSCOPES FROM STOCK. 



ZEISS MAYER DISSECTING MICROSCOPE. 



HEARSON BACTERIOLOGICAL INCUBATORS with Patent Capsule Temperature Control. 



VANIER COMBUSTION TRAIN for the Determination of Carbon in Steel by the Direct Combustion 

 Method with Electric Furnace. 



REPLACEABLE UNIT ELECTRIC LABORATORY FURNACES (Kohn System). 



INSTRUMENTS OF PRECISION FOR THE STUDY OF THE CIRCULATION ( Jacquet Sphygmocardio- 

 graph, Uskoff Sphygmotonograph, Mackenzie Polygraph, etc., etc. 



AMERICAN STANDARD INCUBATORS AND STERILIZERS for Gas, OU and Elactric Heating. 



The 1913 edition of oar catalogue of Chemicals for Analysis, Microscopy, Bacteriology, etc., is 



in format identical with the ahove and for convenience will be bound with our new apparatus cata- 

 logue. It is now ready for distribution separately. 



Any of the above sent upon application 



ARTHUR H. THOMAS COMPANY 



IMPORTERS AND DEALERS 



MICROSCOPES, LABORATORY APPARATUS AND CHEMICALS 



1200 WALNUT STREET, PHILADELPHIA, PA. 



The LEITZ DOUBLE EYEPIECE with Pointer 



Time-saver 

 for the 

 Teacher 



D. R. a. M. No. 435297 



A 



Big Help 



to the 



Student 



It enables the simultaneous observation by two persons, one (the student) at the vertical 

 eyepiece, the other (the teacher) at the auxiliary eyepiece. 



Either person may operate the pointer, which moves over the entire field. The construction of 

 this almost Indispensable accessory may be learned from illustration — detailed description on request. 



For demonstration purposes this double eyepieceis unsurpassed. Both images are sharply 

 defined, colorless and free from distortion. 



Made in two ma.gnifica.tions-4i and 6x 



u. s. 



Branch 



'Price. Duty Free $15.00. 



INew Vork: 

 30 B. 18th St. 



