2f>() VARIATIONS OF BPECIFIC GRAVITY. 



These experiiiicnts have hitely been continued in Basel by my col- 

 U'lifjue, and he finds that "lowed i)hitinuin wire 0.+ nnn. in diameter 

 of specific Gravity i^l.l^UT fell ofl' in density to 21.4133 when drawn 

 to 0.1 mm., and on being heated white hot ayain rose to 21.4346. Wires 

 of chemically pure platinum, an alloy of platinum with 10 per cent 

 iridium, aluminum, and cop{)er all behave in a similar manner, and 

 rolled aluminum foil and hanunered zinc plates as well. 



A cliange of electrical conductivity had previously been noted after 

 incandescence in cold-drawn wires of platinum, platinum-iridium, 

 alumimim, and copper. 



These researches will be continued in all the directions here indi- 

 cated, and an attempt \\ ill be made to measure the alterations by the 

 volumetric method. 



