COMPLBTPJ FREEZING-POINT CURVES OF BINARY ALLOYS. 
41 
For the first five atomic per cents, at least, the moment of freezing' is detected by 
the person stirring a second or two before the observer at the galvanometer, as the 
walls of the crucible become abundantly coated with a smooth solid. 
At 22 atomic per cents, nuclei of silver wet e added just before the reading, but no 
effect was noticed, and the nuclei of silver did not melt easily. 
At 35’23 atomic per cents., and at a temperature considerably above the F.P., 
some of the alloy was extracted. 
At the higher freezing point at 54‘34 atomic per cents., and for 50° or more below 
the F.P., no solid could be detected, but the reading was well-marked. The lower 
F.P. was obtained by allowing the alloy to cool to the eutectic state, 
A portion of the alloy was now removed ; the F.P. afterwards was a degree low^er. 
At 65T 7 atomic per cents, a portion of the alloy was removed, the F.P. before and 
after this process being the same. 
At and after 54 atomic per cents., little or no solid matter can be detected at the 
point recorded as the F.P., but the cooling at this point suddenly becomes much 
slower. 
At 75*5 atomic per cents, no solid matter could be detected until close to the 
eutectic point. Soon after this point was reached the alloy set to a solid mass at the 
eutectic temperature. 
Table IIIb.— Freezing Points of Alloys made by adding Silver to Tin. 
180 grams Tin, 
(1.) 
Total weiglit of 
silver jjresent. 
(2.) 
Percentage of 
silver. 
(3.) 
Atomic 
percentage of 
silver. 
(4.) 
Freezing point on 
the Centigrade 
scale. 
(5.) 
Atomic fall. 
0 
0 
0 
232-07 
3-289 
1-80 
1-96 
226-54 
2-82 
6-579 
3-53 
3-85 
221-67 
8-224 
4-37 
4-76 
(221-59) 
59 
232-5 
IT5I3 
6-01 
6-54 
2.59-5 
18-092 
9-13 
9-91 
296-9 
24'67 
12-05 
13-04 
3-22-6 
36-18 
16-74 
18-04 
355-2 
49-34 
21-52 
23-08 
380*8 
. 
It is clear that the eutectic state is reached with somewhat less than 3*85 atomic 
per cents, of silver. 
The readings, higher than the eutectic, until 10 atomic per cents, of silver, are 
very fugitive, the P.P. being indicated by a slight change in the rate of cooling. One 
MDCCCXCVII.-A. G 
