Supplement to '' Nature^' June 24, 1922 



CHEMICAL 

 REAGENTS. 



MESO = THORIUM 



and 



MESO = THORIUM 

 RESIDUES 



HOPKIN &W1LLIAMS LIP 



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Spencer Portable Microscope 



The open case, showing: No. 60 

 complete, the mechanical stage 

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All metal case. Total weight, 

 with lenses, etc., 9^ lbs. 



Thoma - Hawksley 

 Hsemacytometers, 

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The closed case. 



Catalogues free. 



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SCREW THREAD 

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OPTICAL GLASS 



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 BINOCULAR GLASSES ASTRONOMICAL 



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