86 



Prof. G. Quincke on the Constants of 



The silver was stated to be chemically pure \ the gold was 

 slightly alloyed with silver, chiefly to facilitate the process of 

 wire- drawing. 



Glass threads, drawn out before the lamp from a thicker piece 

 of glass, were also treated like wires. The determinations, how- 

 ever, were less trustworthy, because glass becomes soft before 

 melting, and accordingly, through a commencing drop-formation 

 above the fluid drop, the glass cylinder from which the drop falls 

 off is really widened. A series of determinations was made for each 

 wire, and the mean of them taken. The results collected below 

 prove that the weight of the drops really increases (as it ought to 

 do according to theory) in proportion to the diameter of the wires. 



Silver. 



Gold. 



Glass. 



2r. 



W. 



a. 



2r. 



W. 



«. 



2r. 



millim. 

 0-6709 

 0-5232 

 0-2441 

 0-2006 



W. 



u. 



millim. 

 0-4971 

 0-2318 

 00993 

 00775 



grm. 



0-0733 



00299 



0-0130 



00110 



mgrms. 

 4714 

 41-13 

 41-66 

 41-09 



millim. 

 0-2566 

 0-2009 

 00695 



grm. 

 0-080 

 0-0/5 

 0-0215 



mgrms. 



99-24 

 103 



98-42 



grm. 



00422 



00273 



0-0134 



00115 



mgrms. 

 20-02 

 16-62 

 1748 

 18-24 



Mean 



42-75 





Mean 



100-22 





Mean 



1809 



6. The measurements for platinum and palladium wires were 

 made in the same way as those for gold and silver. Oxygen, 

 however, was conducted into the gas-flame through a platinum 

 nozzle. Palladium was volatilized with such remarkable rapi- 

 dity in the oxyhydrogen flame, that I might compare the palla- 

 dium drops in this respect to ether drops at the ordinary tem- 

 perature. The melting- and boiling-points appear to be very 

 near each other, since I was unable with an ordinary blow- 

 pipe-flame (the pointed flame of the glass-blowers) to melt the 

 metal; the drop lost more by volatilization, as soon as it had 

 attained a certain size, than it gained by fusion of new wire. 

 Accordingly I found the values of u always too small in my nu- 

 merous experiments, and that which I give below makes no pre- 

 tence to accuracy. When palladium solidifies, there are formed 

 on the smooth drop -surface needle-shaped excrescences, which 

 give the mass a peculiar appearance. 



Platinum. 



Palladium. 



2r. 



W. 



cc. 



2r. 



W. 



K. 



mgrms. 

 163-4 



millim. 

 0-5675 

 0-3689 

 01921 

 0-09.03 

 0-0767 



grra. 

 0-2912 

 0-2055 

 0-0996 

 00530 

 00410 



mgrms. 



163 



177-4 



1651 



169-8 

 169-9 



millim. 

 0-6829 



c;rm. 

 0-1300 



Mean 



169-04 



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1 



