11 
dryness on the water bath, and taking up with absolute 
alcohol. 
(a) Salt prepared by direct solution of the metal in Per- 
chloric Acid; 0*1831 salt yielded 0*2476 Chloroplatinate. 
(b) Salt prepared by double decomposition; 0*4502 salt 
yielded 0*6060 Chloroplatinate. 
(2) Determination of Perchloric Acid. A solution of 
Potassium -acetate was added to the Thallium-perchlorate, 
and the whole evaporated to dryness on a water-bath, the 
acetates of Thallium and Potassium washed out with absolute 
alcohol, and the insoluble Potassium-perchlorate collected on 
a weighed filter ; 0*4570 Thallium-perchlorate yielded 0*2100 
Potassium-perchlorate. Hence : 
Calculated. 
Found. 
i. 
II. 
III. 
Tl... 
...204*0 
67*21 
67-38 (a) 
67-18(b) 
Cl... 
... 35*5 
21.09 
1 
|- 32-96 
o«... 
... 64-0 
11*70 
J 
303*5 
100*00 
“ Catalogue of Binary Stars, with introductory Remarks,” 
by A. Brothers, F.R.A.S. 
The Author said that the purpose for which he had pre- 
pared a list of the stars known to be Binary at the time of the 
publication of Smyth’s 6i Cycle” was to bring down the 
information as to the positions and distances of those stars to the 
present time, and for this object he had obtained the necessary 
information from some of the most eminent observers. He 
had found much inconvenience from having to examine a 
number of catalogues for the information he required for his 
