166 



In the first part of their Paper the Authors treat of the 

 conductibility of mercury, and prove that if the source of heat 

 be applied at the upper part of a column of mercury, so as to 

 prevent any motion of the solid molecules of the mercury, 

 this metal becomes the worst conductor of all known metals ; 

 for, silver being 1000, mercury is 54. 



In the second part of their Paper the Authors examine the 

 conductibility of the solid and semisolid amalgams prepared 

 in equivalent quantities of pure metals with mercury, and 

 they show that amalgams may be divided into two classes — 

 those containing an excess of equivalents of the amalgamated 

 metal, and those which on the contrary contain an excess of 

 equivalents of mercury. The first class conduct heat at the 

 mean rate of the two metals composing the amalgam, and in 

 accordance with the calculated result, as shown by the follow- 

 ing table. 



Amalgam of Tin. 



Mercury = 21-63 or 679 

 Tin....= 13 45 or 422 



Silver = 1000 



Found. Calculated. Found. Calculated. 



6 Sn. Hg 10-60 15-M 332 .... 4/8 



5 „ „ 10-30 15-63 323 490 



4 „ „ 9-65 15-88 .... 302 .... 498 



3 „ „ 9-45 16-30.... 296 571 



2 „ „ .... 8-65 .... 17-19 .... 271 .... 539 



Sn. Hg 5-15 18-56 161 582 



„ 2 Hg 4-75 .... 19-75 .... 149 .... 619 



„ 3 Ilg 4-20 20-26 .... 131 .... 635 



,, 4Hg 3-95 .... 20-55 .... 124 644 



„ 5 Hg 3-65 20-73 114 650 



The second class, comprising those amalgams containing 

 an excess of mercury, conduct heat as if they contained no 

 other metal, although its proportions may vary from 10 to 34 

 per cent. 



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