LABORATORY SUPPLIES AND CHEMICALS 



329 



>150 



5152 



5150 FORCEPS, Dissecting, best quality, nickel plated, straight, with fine, file cut 



points, 4J/2 inches long 50 



5152 FORCEPS, as above, curved, 4J^ inches long 50 



5158 



5154 HAElMACYTOMETER, American Standard, complete with Levy counting 

 chamber with Neubauer ruling, with two cover glasses and one pipette 

 for red and one for white corpuscles, in leather case $15.00 



5156 HAEMACYTOMETER, American Standard, complete with Levy counting 

 chamber with Neubauer ruling, with two cover glasses and one pipette 

 for red and one for white corpuscles, in leather case, with Bureau of 

 Standards certificate for both counting chamber and pipettes 20.00 



5158 HAEMACYTOMETER, American Standard, complete with Levy counting 

 chamber with double Neubauer ruling, with two cover glasses and one 

 pipette for red and one for white corpuscles, in leather case 18.00 



5160 HAEMACYTOMETER, American Standard, complete with Levy count- 

 ing chamber with double Neubauer ruling, with two cover glasses 

 and one pipette for red and one for white corpuscles, in leather case, 

 with Bureau of Standard certificate for both counting chamber and 

 pipettes 24.00 



The Levy Counting Chambers possess the following distinct characteristics: 



Increased visibility of the rulings when chamber is filled with solution. 

 The new method of construction entirely avoids the cemented cell and the 

 attendant danger of its looseniqg by the drying out of the balsam cement, 

 and the possibility of the loosening of the ruled counting surface is also 

 greatly reduced by this construction. 



The parallel form of cell first suggested by Biirker and used in all Levy 

 counting chambers provides a more uniform distribution of corpuscles over 

 the ruled area and entirely removes the effect of atmospheric pressure 

 upon the depth of the solution, a souce of considerable error in the 

 circular form chambers. 



