On the Atomic Weight of Glucinum. 



the same current passes. Three experiments gave the mean result, 

 Jc 10 = 0-4085. 



The general mean of these experiments is A- 10 =0'4112. 



The specific heat of water was taken as 1*0000 at 0°, and the cor- 

 rection for temperature used was that obtained bj Miinchhausen and 

 Willlner, and by Baumgartner and Pfaundler, viz., kt=l + 0'0003'#. 

 JRegnault's expression for the change in the specific heat of tur- 

 pentine was employed, i.e., kt=Jc + 0'00124it, omitting the third 

 term, which only inappreciably affects the results in the small range 

 through which the liquid was heated. 



The following table contains the results of the specific heat deter- 

 minations of glucinum* made with this apparatus. Column I gives 

 the results actually obtained ; Column II these results corrected for 

 the impurities contained in the metal : — 









I. 



II. 



Experiments 1 and 2 » . 



c 100 



= 0-4267 



0-4286 





3 „ 4 .. 



,.13 



= 0-4500 



0-4515 



»> 



5 „ 6 .. 



c 193 



= 0-4676 



0-4696 





7 „ 8 .. 



-15 



= 0-4866 



0-4885 



» 



9 „10 .. 





= 0-5087 



0-5105 



These numbers show a rapid and continuous increase in the specific 

 heat as the temperature rises. In order to find whether this increase 

 scontinued above 300°, two experiments were made at higher tempera- 

 tures with a double calorimeter. This calorimeter consisted of two 

 thin brass vessels, placed close together with suitable thermometers 

 and agitators. One of these received the glucinum, and the other a 

 platinum cylinder of known weight. These two substances were 

 placed in two similar glass tabes, packed side by side in a wide iron 

 tube with slag- wool, and the whole heated in the furnace which was 

 used for the vapour- density determinations. f After the heating had 

 been continued for about three hours, the iron tube was withdrawn, 

 and the substances quickly tipped into the calorimeters. In calcu- 

 lating the temperature, Violle's results of the specific heat of platinum 

 at varying temperatures were used. These two experiments gave th 

 following results : — 



I. II. 



Experiment 11 = 0-5178 0-5199 



12 e% 7 = 0-5384 0-5403 



which show that although the specific heat continues to increase, iv 

 does so more slowly than at lower temperatures. 



* The metal was enclosed in a platinum capsule, soldered air-tight with pure gold . 

 t See Sequel. 



