CHAS. LENTZ & SONS 
Apparatus for Counting Colonies of 
Bacteria, etc. 
No. 2548 
No. 2552* 
2546. Printed charts, for counting colonies of bacteria in Petri dishes. 
The colonies are counted in one or more sectors and mul- 
tiplied by the number of such sectors in the area of dish. 
Per dozen $0 60 
2548. Wolfhugfel^s Counting: Apparatus 3 50 
2550. Miller-McPherson Counting Apparatus, for Petri dishes or 
Miquel flasks, as used by W. P. Mason, of the Renssalaer 
Polytechnic Institute, Troy, N. Y 12 00 
2552. Sedg-wick's Aerobioscope.— A glass tube of large diameter, con- 
nected to a smaller tube at one end, and with a constriction 
and lip at other end, engraved into squares, with funnel. Each, 2 00 
2554. Lentz^s Colony Selector.— A mechanical finger attachable to 
the nosepiece of microscope, provided with platinum needle, 
so that an exceedingly minute colony can be selected from its 
closely packed neighbors in a Petri dish with little risk of con- 
tamination, saving time and the necessity of another inocula- 
tion in obtaining pure cultures of bacteria. Price 10 00 
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