LABORATORY SUPPLIES AND CHEMICALS 



321 



5026 



5028 



5026 IMMERSION OIL DROPPER; This is a new device and fills a real need for a 

 convenient and thoroughly clean method of handling and applying immer- 

 sion oil to the object slide when used with immersion-oil objectives. It 

 drops just one drop of oil at a time exactly where wanted by simply hold- 

 ing in position, point dov/n over the slide, and pressing the top with thumb, 

 or finger. For refilling with immersion oil, the top portion is easily re- 

 moved by simply unscrewing same. 

 Price $2.00 



5028 COUNTING APPARATUS, Wolffhuegel's. For counting colonies of bac- 

 teria in plate cultures. Consists of a wooden base, 270 mm. square, 

 with drawer for accessories, and a ruled glass plate. The rulings are 

 10 mm. squares, with the diagonal rows ruled to 3 mm. squares. The 

 ruled surface is 120 mm. square. Black and white backgrounds are 



provided $7.50 



Extra ruled plate 3.00 



5030 



5032 



5030 COUNTING PLATE, Jeffer's; ruled on glass; for use with the Wolffhuegel 

 apparatus; the circular surface is divided into sectors which are sub- 

 divided into small spaces of equal area. (See Journal of Applied 

 Microscopy and Laboratory Methods, Vol. 1, No. 3.) $2.50 



5032 COUNTING PLATE, of paper, 4 inches in diameter, for use with Petri 



dishes, per doz 50 



COUNTING APPARATUS, Stuart's, consisting of 







a hardwood box carrying a 16-candle-power, 

 110-volt electric lamp and with adjustable 

 platform for holding Petri dish, which is il- 

 luminated by the oblique rays from the lamp, 

 complete with counting plate $17.50 



5034 



