of Edinburgh, Session 1876-77. 303 
the substance in question grew on the brass binding screws, and as 
a thin layer on the carbon. The external appearance of the mass 
was reniform, the colour ranging from a pale blue to a dark purple 
and lilac tint; the portions from the carbon were of a pale green 
shade, and of no special shape. The quantity being small, it was 
impossible to make more than one analysis of each substance and 
that only with very small quantities. The exterior portions which 
showed no crystalline structure, and were efflorescent, appeared to 
contain less water than the interior portions, which possessed a 
paler colour, the composition being otherwise the same. The in- 
terior was not homogeneous, as particles of some white substance 
could be distinguished scattered through the mass. The dark purple 
and green portions, when heated to 100° C, give off ammonia and 
water in varying quantities (NH 3 2-02-0*87 per cent.), and left a 
bluish green powder, which was only slightly soluble in water or 
in dilute sulphuric acid, but easily dissolved with effervescence by 
nitric or hydrochloric acid. The original substance treated with 
water formed a blue alkaline solution, resembling that produced by 
the solution of cupric hydrate in excess of ammonia, a green residue 
being left undissolved, which, with potassium hydrate, yielded 
ammonia. 
The analyses point to a formula, 
Cu 2 Zn 4 Cl c (NH 3 ) 4 C0 3 . 
If the carbonic anhydride be present as zinc carbonate, and in all 
probability the above-mentioned white particles are (ZnC0 3 ), we 
have present the substances, 
(2NH 3 Cu)C 1 2 + (2NH 3 Zn)Cl 2 + ZnC0 3 + ZnCl 2 . 
Also was found (NH 4 ) 2 (NH 3 ) 3 Cl 5 Cu 2 Zn 3 C0 3 , 
And in another analysis, no carbon dioxide being present, 
Cu 2 Zn a (NH 3 ) 3 Cl 4 . 
In contact with a portion of the substances analysed was metallic 
copper; this may probably account for the varying quantities of 
combined copper in its immediate neighbourhood, some of the 
results obtained indicating the presence of an ammonio-cuprous, 
as well as of an ammonio-cupric compound. No trace of metallic 
zinc could be found. 
