236 J. P. Cooke on Stibiotrizincyle and Stibiobizincyle. 
was not however able to obtain crystals from alloys either of 
49 p.c. or 53 p.c. of zinc, whose angles could be accurately - 
measured. 
This result is certainly very remarkable and important in its 
theoretical bearings, and will be the more so should it be found 
that the same variations in composition appear in the compounds. 
Until I have investigated these I shall refrain from advancing my 
views on the subject. The facts just stated are substantiated by 
a very large number of analyses and measurements besides those 
which appear in this paper. 
Stibiobizincyle. 
This compound may be easily prepared like the last by crys 
tallizing an alloy containing about 33 per cent. of zinc, and 67 
per cent. of antimony. In its natural state like Stibiotrizincyle, 
it has a silver white color, and a very bright metallic lustre, often 
however its surfaces display prismatic colors owing to oxydation. 
It forms in right rhombic octahedrons with. basal planes of the 
Trimetric System. Here as in the other crystals, I have observed 
variations in the angles amounting to 20 minutes between the ex- 
tremes. The crystals are frequently very perfect and their faces 
so plane and bright, that the angles can be measured to a minute. 
The angles given were all obtained by measurement, except the 
one over X, which measured six minutes more than that required 
by the other two. These angles are nearly the mean of those 
observed. 
O on 1 = 122° 15’ measured on 2. 
each side. —Ey 
1 on 1 over Z = 115° 30’, meas- fei] 
ured. . |: 
1 on 1 over Y = 118° 24’, meas- NC ae 
ured. 
1 on 1 over X = 95° 24’, meas- 
ured 95° 30/. 
Axesa = 1, b = 1-042, c= 0-793. 
rhc crystals were analyzed by Mr. Eliot with the following 
results : 
: Analysis, Theoretical Sb Zn2- 
Zinc == 32°62 Zine 33°55 
Antimony = 66°86 Antimony 66°45 
99:38 100:00 
I have now given an abstract of the results on these tw new 
compounds which I have obtained up to this time. Iam now 
engaged in investigating their chemical relations and compounds. 
The results of this investigation I hope to be able to publish dur 
ing the Autumn, in the form of a memoir, to which I must! 
