LABORATORY SUPPLIES AND CHEMICALS 



3737 



3737 RINGS, concentric, of copper, tinned inside. 



Number of rir gs in set 3 4 



Outside diameter, largest, inches 4 5 

 Each $0.80 1.00 



1.25 



5 



6 



1,50 



2.00 



10 

 3.50 



9 



12 

 6.00 



3738 



3740 



3738 RINGS, extension, to attach with clamp holder. 



Sizes, inches diameter 2 3 4 5 6 



Each f $0.12 .15 .18 .20 .25 



3740 RINGS, iron, for supports with clamp; can be attached to any size rod. 



Diameter, inches 2- 3 4 5 6 



Each $0.15 .20 .20 .25 .25 



3740(a) 



3740(a) ROASTING DISHES, of clay, very shallow. 



Diameter, inches 2J/ 3 4 5 6 



Dozen $0.70 .80 .90 1.10 1.75 



3741 RODS, Glass, best American lead-free, in 5-ft. lengths. 



Diameter, 3-25 mm. ; per pound $0.50 



RODS, Stirring, any size and thickness, with smooth rounded ends. 



3742 RUBBER CAPS for Test Tubes. 



Diameter, inches ^4 1 1% 3 



Per dozen $0.40 .50 .60 1.25 . 



3743 



3743 RUBBER, Policemen, for scraping precipitates from walls of beakers, etc., 



to be used on glass rod; without rods $0.10 



3743 (a) 



S743(a) RUBBER, Policemen, Blair's, with glass rod, for removing particles of pre- 

 cipitates from walls of beakers, etc., as described in Blair's Analysis 

 of iron. 

 Diameter of flat end, inches .............. , ................ A T& 



Each ..................................................... $0.10 .12 



Per dozen ................................................. 80 1.00 



3744 RUBBER, Policemen, as above, without glass rod. 



Diameter of flat end, inches ............................... & 



Per dozen ................................................ $0.60 



.75 



