SCIENCE 



KBw Series 

 Voti LI, No. 1S21 



Friday, Apkil 23, 1920 



Single Copies, 15 Cts. 

 Annuai, Scbsobiptioh, H.OO 



STANDARDIZE YOUR TESTS 



DV BOSC COl.ORIIIIE'reR. 



WE are headquarters for Bacteriological, Biological, and Chemical 

 Laboratory Supplies of all kinds. These include Colorimeters, 

 Microscopes and Microscope Accessories, Incubators, Sterilizers, 

 Balances, Chemical Reagents, Drugs, and Stains, Extraction Apparatus, 

 Filter Paper, Glassware of all kinds, Hydrometers, Nitrogen Determina- 

 tion Apparatus, Platinum and Porcelain Ware, etc. 



Write for catalogs and bulletins, also information in regard 

 to Hydrogen-ion and other forms of new apparatus 



HTnEY* ^^AmEnd 



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 PITTSBURGH BRANCH 

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