in the Compounds of Zinc and Antimony. 225 
ted, and, as the three analyses cited in the former paper prove, 
have the same composition as the alloy. On increasing gradually 
the amount of zinc in the alloy up to 48:7, the crystals continued 
to have the composition of the alloy, and the only difference, 
which could be observed in their character, was, that they were 
smaller and more frequently isolated. Between these limits, 
the whole mass of the alloy exhibited a strong tendency to crys- 
tallize, and, by pouring it, as it cooled, from one vessel to another, 
it could be crystallized to the last drop. The portion a, b, of the 
curve is therefore a straight line equally inclined to the two axes. 
On increasing the amount of zine in the alloy to 50-7 p. c., the 
amount of zinc found in the crystals was only 46°89 p. c., and 
above this it was uniformly less than it was in the alloy ; but no 
closer relation between the two could be detected, owing un- 
doubtedly to the unavoidable irregularity in the crystallizations 
of the alloys, which contained more than 50 p. c. of zinc. This 
arose from a peculiar pasty condition, which the fluid mass as- 
sumed, at the point of crystallization, apparently caused by the 
separation of the excess of zinc. Definite crystals however were 
obtained even from the alloy of 60 p. ¢. of zine, which contained 
p. ¢. ; above this, the crystals became less and Jess abundant, 
and gradually faded out, alihough the alloy even of 86 p. c. of 
zinc exhibited a radiated crystalline texture ; and a trace of this 
structure could still be discovered even in the alloy containing 
only 4 p. c. of antimony. It might be supposed that on return- 
ing to the alloy of 42°8 p. c. of zinc, and increasing the amount 
of antimony we should obtain crystals containing an excess of 
antimony ; but so far is this from being true that the slightest 
excess of antimony entirely changes the character of the erys- 
tallization. On crystallizing an alloy containing 41°8 p. e. of zine 
Not a trace of any prismatic crystals could be seen, but in their 
place there was founda confused mass of thin metallic scales, 
which, as will soom be shown, are imperfect erystals of Sb Zn2. 
Thus it appears that although perfectly formed crystals of Sb Zn 
can be obtained containing 55. p. c. of zinc they can not be made 
to take up the slightest excess of antimony. 
In order to obtain crystals having the composition of Sb Znz, 
that is, containing 33°5 p. c. of zine, it is necessary to erystallize an 
* this point large com- 
hen erystals are obtained sable ae to the large crystals of 
a 
Secon Senms, Vol. XX, No. 59—Sept. 1855. 
