LABORATORY MANIPULATION 



be rolled in the cork press. With the small pointed end 

 of the round file make a hole through the center of the 

 cork, or a little to one side if directed to do so. This 

 hole should be perpendicular to the surface of the cork. 

 In making a hole, the cork should be held in the left hand, 

 and the larger end should be placed against the edge of 

 the desk. The file should be held in the right hand, and 

 only enough pressure exerted to perforate the cork. By 

 means of the round end of the file, the opening thus made 

 is enlarged until the desired size is obtained. The hole 

 should be a suggestion smaller than 

 the tube it is to receive, which can be 

 inserted easily if well annealed and 

 wet. When inserting a tube in a 

 cork, never push the tubing toward 

 the palm of the hand, or use too much 

 pressure ; otherwise severe cuts may 

 be received from breaking of the glass. 



Fig. 4. Inserting glass 



Hold the cork in the left hand as tube into cork, 

 shown in Fig. 4, and then with the right hand carefully 

 insert the tube. 



27. Weighing. In this work, the metric system of 

 weights and measures is employed, and it is taken for 

 granted that the student is familiar with the system ; if 

 he is not, he should review the subject as given in any 

 ordinary arithmetic. 



Note. kilo = 2.2046 Ibs. (avoirdupois). 

 = 28.35 gms. 

 = 453-59 gms. 

 = 1.05708 U. S. quart. 

 = 2.54 centimeters. 

 39.3808 inches. 



kilo 



oz. 



Ib. 



liter 



inch 



meter ; 



