COMPLETE FREEZING-POINT CURVES OF BJNARY ALLOYS. 
55 
At the conclusion of the experiments, the alloy was weighed and 'found to l)e 
404'5 grams instead of 4I0'6 grams, the weight of the metals used. 
The weight of the silver used was not known to nearer than one o’ram, and this 
silver was slightly contaminated with nickel, and perhaps with iron. 
Up to 4*01 atoms of bismuth the freezing point was marked by plenty of precipitate. 
At 12*45 and 18*96 little or no precipitate was noticed at the moment of reading 
the freezing point, and this point was very fugitive. Some time after the freezing 
point, a large quantity of a fine sandy precipitate formed, and stirring was possible 
in this for a considerable time, the rate of cooling being very uniform. 
Table X,—Freezing Points of Alloys made by adding Thallium to Silver. 
200 grams Silver. 
(!•) 
Total weight of 
thallium present. 
(•2-) 
Percentage of 
thallium. 
(3.) 
Atomic 
percentage of 
thallmm. 
1 
1 (4.) 
Freezing point 
on the Centigrade 
scale. 
(5.) 
Atomic fall. 
0 
0 
0 
962-38 
2-639 
1-30 
-69 
956-83 
8-01 
6-709 
3-26 
1-74 
946-4 
9-16 
1 > 
947-1 
8-77* 
14-127 
6-60 
3-60 
930-5 
8-86 
21-786 
9-82 
5-45 
913-5 
8-97t 
Section IV. 
Discussion of the Experimental Curves. 
The curves (tigs. 6-20), which embody the results of our experiments, aie plotted 
with the temperature of the freezing point of the alloys measured vertically upwards, 
and the atomic percentage measured horizontally. We can hence at once get the 
value of the concentration x for use with equations (1) and (2). The numbers just 
below the line of the curve give the temperature, those just above give the atomic 
percentage of one metal. The individual experiments are given by the black points 
which lie along the course of the curve. 
Dilute Solutions. - - 
When a solution is very dilute, the observed depression of the freezing point is 
necessarily small, and consequently the atomic fall is liable to a large experimental 
* Next day’s reading. 
t At the end of the experiiueuts the alloy was found to weigh 2il'2 grams ; the total weight of the 
two metals used was 221'8 grams. 
