58 Contributions to Chemistry from the 
tion as that of the ring.” He even found that still smallet 
globes were formed. ; 
4, If a small disc is put into very rapid rotation, a ring is 
formed, while a part of the original globe remains on the — : 
($21), so that Plateau rightly concludes with saying ($27) that 
of the phenomena of the relative configuration of the 
aia y bodies have been reproduced by him on a small scale” 
[Zo be continned.} 
—————— 
a 
Art. VIIIl.— Contributions to Chemistry from the mcedney he lie 
Lawrence Scientific School; by Wotcorr Grins, M.D., 
ford Professor in Harvard University.—No. 2 
§ 1. 
On the separation of chromium from aluminum, tron, mange 
nese, cobalt, nickel, zinc and _magnesium.—Sesquioxyd of chro- 
mium in an alkaline solution i is readily aera to chromic acia — 
dium is added in excess, a current of chlorine gas, or a solution 
chlorine water, readily converts ‘the whole of the chromium pree 
ent into chromic acid, especially when the solution " ne 
when it is kept nearly neutral By occasional addition of carbor 
of hock um. The excess of chlorine is easily expelled bi "poilingy 
; for in this oil the density is the same. See our article, thie 1a 
oe. 1864, xxx, xxxvii, 51, 6=0, 
hf ee la difference des lois que suivent les forces attractives dans ce cas ¢ 
celui des grandes masses planétaires, nous avons vu se uire, en petit, une 1 
présentation ation frappante de Lx pluspart des es phénoménes ph pio ree / 
corps célestes, ee 
