14 



ENERGY CHANGES INVOLVED IN DILUTION OF AMALGAMS. 



Let w x be the weight of amalgam A t , which is diluted with w 2 grams of 

 mercury to form a new amalgam, A 2 ; the percentage composition of A 2 is 

 now calculated ; then the densities of A x and A 2 are found from the curve to 

 be D 1 and D 2 , respectively. 



l + W, 



l Hx = A __ w x +w 2 x _A . 



-1 



f2 



^, 



A 



ze>, 



/? 



13.36 



I3.3S 



13.40 



1342 



13.44 



1346 



1348 



13.50 



I3.5E 



13.54 



"" OA 0.8 1.2 1.6 Z.O Z.4- 2.8 3. 



Fig. i. The Densities of Zinc and Cadmium Amalgams. 

 Density is plotted ordinately; percentage composition in the direction of abscissae. 

 The shorter lines represent zinc ; the longer, cadmium amalgams. The dotted lines 

 give the theoretical values which would be observed if no contraction took place on 

 mixing; the continuous lines give the actual values. 



