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XXXIII. A new Form of Pyhiometer. 

 By R. V. Stanford*. 



THE construction of this modification o£ the common 

 U-shaped pyknometer will be seen from the accom- 

 panying sketch. It maybe readily made before the blowpipe, 



*-5777m* 



of any desired content from 1 c.c. upwards. It is filled with 

 the liquid whose density is desired by attaching at B a tube 

 which dips into the dish containing it, and applying suction 

 at A. The apparatus, entirely filled with liquid at room 

 temperature, is placed upon a stand in a thermostat, and the 

 plunger CD affixed at B by means of rubber tubing. When 

 the liquid has attained the temperature of the bath, a finger 

 is placed over the aperture E in the piston-rod, and the piston 

 depressed until the liquid meniscus has descended to the 

 mark a. The finger is then removed from E, the plunger 

 detached, and the instrument removed from the thermostat 

 and weighed. The plunger consists merely of a piece of 

 glass tubing some 0*5 cm. outside diameter, into which a 

 smaller tube fits, as shown in the figure. The piston is made 

 airtight by means of a small rubber ring. 



This form of pyknometer has the advantages that it dis- 

 penses with a wire suspension, and that the adjustment to the 

 * Communicated by the Physical Society : read June 16, 1905. 



