﻿316 



The Philippine Journal of Science 



1914 



(c) Hold the shank of the pipette in the right hand, and with 

 a pair of fine forceps held in the left grasp the capillary at 

 a point about 6 centimeters from the shank. The outer sides 

 of both hands should rest on the table. Bring the portion of the 

 capillary next to the forceps over the flame and at right angles 

 to it, then lower it to a point above, not in, the flame (fig. 5) . 



{d) Pull gently with the forceps, and when the glass begins' 

 to soften lift it slowly from the flame and pull with the forceps 

 slightly more than at first, but not too strongly. The hands 

 should remain on the table during the process and the pulling 



Fio. 5. Method of making the capillary pipette, h, microburner. 



and lifting done by turning them slightly outward. The 

 capillary will separate with a slight tug — a feeling much like 

 that experienced when a taut thread, held in the fingers, is 

 parted in a small fiame. If the point is properly made, it will 

 appear as shown in h (fig. 6) . 



This capillary has sufficient rigidity, and it comes to a very 

 fine point. The tip is closed, but the lumen extends to the 

 very end. 



It is evident that everything depends upon the amount of 

 heat used and the timing of the pull and that these must vary 

 slightly with the height of the flame and the diameter of the 



