Measurement of Area and Volume 39 



22. The volumes of liquid bodies are generally 

 determined by using measuring vessels of suitable 

 size, which are graduated in different ways, according 

 to the purpose for which they are intended. 



A in Fig. 16 represents the "pipette". This is 

 used when a given volume, consisting of a whole 

 number of c.c., such as 5, 10, 20 or 50 c.c., is required 

 to be delivered into another vessel. One graduation 

 mark only is needed, situated on the upper part of 

 the stem. The pipette, when filled with water to this 

 mark, will deliver the volume of liquid marked on its 

 bulb. This should be allowed to run out freely and 

 the small quantity left in the jet should be permitted 

 to remain there, as this is allowed for when graduating 

 the instrument. 



By means of B, the "burette", volumes involving 

 fractional portions of a cubic centimetre may be 

 measured, the graduations on the body of the burette 

 usually showing cubic centimetres and tenths of a 

 cubic centimetre. Burettes are constructed to deliver 

 total volumes of 10, 25, 50 or 100 c.c. 



The measuring flask, (7, holds the number of c.c. 

 marked on it when filled to the mark on its neck. 

 Flasks of varying sizes are in common use, those most 

 frequently met with being constructed to hold 50, 100, 

 200, 250, 500 or 1000 c.c. Some flasks will be noticed 

 as having two marks on the neck. When filled to the 

 lower mark the flask contains the volume marked on 

 its body. When filled to the upper mark the volume 

 marked on it may be poured from it. The volume 

 between the two marks is the allowance made for the 

 drops of liquid which remain clinging to the interior 

 of the flask when it is used to pour out a quantity of 

 liquid. 



