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NEw SERIES. SINGLE CoPIEs, 15 CTs. 
VoL. X. No. 251. FRIDAY, OcToBER 20, 1899. ANNUAL SUBSCRIPTION, $5.00 
Chemicals a Chemical Apparatus 
Carl Zeiss’ and Spencer Lens Co.’s 
Microscopes and Accessories 
60. 50 40 
2 Fallin tu li 
SPENCER’S ATTACHABLE 
MECHANICAL STAGE 
MAX KOHL, PHYSICAL APPARATUS 
STINAYVOHD Hand SJINNVETHVS “dV ‘D 
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