F. W. Clarke—Jodates of Cobalt and Nickel. 285 
“i 3°03, I redetermined it again in person, and got 2°349 at 
My result thus confirms those of Miss bbot, and the 
sicities is raised whether this ener he may not exist in 
more than one modification as regards density. 
ee féflowing series of pyrophosphates was worked up by 
. Lewis. They were prepared by igniting the double 
realise ee 
Mg.P,O., 2°598, 299, and 2° 559, 18°, eohupidee found 2°22, 
3°. 
‘dias of the corresponding aj feheiies were prepared by 
Miss Helena Stallo, as follow 
Mn,As,0., 3°6832 and 3°6927, 298 Also 3°6625, 25°. 
Zn /As,O 4°7034 and 4°6989, 
Mg, As,0., 3°7305, 15°, and 8 eis: ys ha 
Miss Stallo also dletahniiied the ae trisodium ortho- 
arsenate, getting ,2°8128 and 2°8577, 
The following compounds, srceety various series, may 
be regarded as scattering. 
—— sulphate, GISO,, 4H,O, 1°6743, 22°, Miss Stallo. Top- 
oé found for this salt, 1725. The sample Miss Stallo 
easier with was slightly damp, which will account for the 
difference. 
Potassio-chromic oxalate, CrK,0,0,,,3H,O; 271039, 23°, and 
’ tte ae Bisho 
Ae? 
Stannous chloride, SnCl,, oF O, 2°634, 24°, E. P. head The 
published figure obtained by Penny was 2°71, 
Cupro-mercuric iodide, HgI,. Cul, 6°1602, 15°, mt 6° 1412, 18°, 
A eighway. 
Mercurie chloride with ammonium dichromate, HgCl,.Am,Cr,0., 
O, in large crystals, 32336, 21°, and 3-1850, 18°, A. E 
20) 
eighway. 
Mercuric nee eh Hg(C,H,0,),, 3°2544, 22°, and 3-2861, 23°, John 
Hagem 
This inlets the list of determinations thus = made by 
my students. Sixty-three compounds are here given, forty-six 
among them not having been measured before. In concluding, 
I will give a few determinations of my own. 
Potassium iodate, KIO,. There are two published values for this 
t, namely, 3° 979, Kremers, and 2°601, Ditte. Th ary 
from each other so widely that I thought it worth while to 
detente eo salt, and I obtained the figure 3°802, 18°. 
This confirms mers. 
Tellurium dioxide, TeO,, 5°7559, 12°5°, and 5°7841, 14°. Schafa- 
rik found 5-93. 
