68 Domestic Science 



required to exactly fill the flask. From the weight of 

 the water marked on the exterior of the flask the interior 

 volume may be found and the -density of the liquid 

 may thus be readily ascertained. As a check on the 

 accuracy of the value marked on the flask, it may be 

 rinsed out thoroughly with tap-water followed by 

 distilled water and then filled with distilled water and 

 weighed. If the water is at or very near the tempera- 

 ture at which the flask is supposed to contain the 

 weight marked on it, the number of grams of water 

 it holds should be the same as the number of grams 

 marked on the flask. 



Other methods of determining the density of a liquid 

 will be described in later chapters. 



39. The density of a gas, such as air or carbon 

 dioxide, cannot be accurately determined by any simple 

 means. A method which gives roughly approximate 

 results for air will be found fully described in Chapter x. 

 Experiment and further consideration of this point 

 may be postponed till that stage of the work is reached. 

 The density of air being known, the density of other 

 gases may be found by such methods as that described 

 in Chapter x. 



40. The approximate specific gravities of some 

 common substances are given in the table below : 



8-4 

 19-4 

 7'3 

 0-24 

 0-917 

 2-6 



.. 1-8 to 2-8 

 0-8 



Glycerine . . 1"27 Mercury . . 13"6 



Milk . . . . 1'032 Paraffin oil . . 0'81 



Air . . . 0-00129 Carbon dioxide 0-00195 



