( 525 ) 



Putting «', = ff J and r' = r as a first approximation, tlie value of 

 the correction becomes : 



' ^^1-0,74X0,9887 Vl-0,74 X 0,01^ 



and, as at 25° the composition of tlie liquid phase was found 

 a; = 0,988, and that of the solid phase x' = 0,01 (perhaps 0,06), the 

 said value becomes : 



0,745 X (0,0020 — 0,9950) = — 0,74. 

 A change of .v' from 0,01 to 0,06 can only cause a slight alteration. 

 The A'alue of the chief term log— is: 



0,988 

 lor -5-^ X 2,3026 = 4,59, 



so that we obtain (at 25°) : 



, 2 X 298,2 X 234,5 



X 3,85 = 8450 ^ram-cals. 



63,7 



whereas Person found q' = 2,82 X 200,3 = 565 gr. cals. We therefore 

 find a value 15 times too great. And a small error in the correction 

 term 0,74 cannot upset this result. If, however, the tin in the solid 

 amalgam is taken as hexatomic, .1' becomes six times greater and 

 q'g comes down to about 4400 gram-cals. If, moreover, .v' is origi- 

 nally taken not as 0,01, but as 0,06, so that with a hexa-atomicity 

 x' now becomes 0,32, the value q'g begins indeed to get more close 

 to the value, obtained experimentally. 



The above, therefore, contains indications enough of the poly- 

 atomicity of both mercury and tin. To arrive at a decision, however, 

 accurate experiments w ill have to be made in the direction indicated, 

 together with fresh determinations of the two heats of fusion. 



Ethnology. — "Injlueuce of chani/ed comlltlons of Ufe on the 

 pltysical and psyducal development of tlie popidatlon of Centi'al 

 Borneo.'' By Dr. A. W. Nieuwenhuis. 



(Communicated in the meeting of February 28, 1903). 



There is great diversity of opinion among competent authorities 

 about the influence exerted by external circumstances of life on the 

 development of a pei'sou and on that of the peculiarities of a tribe. 



If this difference of oi)inion already gives evidence of the ditTiculty, 

 of determining this influence for the individual, the difficulty is greatly 



