SCIENCE 



New Series. 



Vol. XII. No. 290. 



Friday, July 20, 1900. 



Single Copies, 15 cts. 

 Annual Sdbsckiption, $5.00. 



Chemicals 



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KOCH'S Incubator 



NEW AND IMPROVED FORM, TO WORK WITH A PE- 

 TROLEUM LAMP, INDISPENSABLE WHERE 

 GAS IS NOT AVAILABLE 



Furnished in Four Different Styles and Sizes from $25.00 upwards 



EIMER & AMEND, New York 





