A12 Scientific Intelligence: 
‘““The two oxyds are covered with prussic acid and then potassa is 
added till both are dissolved. ‘The solution is then kept boiling through 
a quarter of an hour.. At the conclusion of the boiling, moist hydra- 
ted oxyd of mercury is added te the hot solution till a part remains 
undissolved. There occurs a green precipitate containing all t 
nickel, with an excess of undissolved oxyd of mercury. By ignition 
there remains pure oxyd of nicke 
Acetic acid is added to the filtrate till the reaction is acid and then 
thrown down with blue vitriol. The blue precipitate contains all the 
cobalt. This is dried, ignited, redissolved in hydrochloric acid, the 
copper precipitated pod hydrosulphuric acid, and then from the filtrate, 
the cobalt with potas 
he method veoeida upon the fact that nickel-cyanid of potassium 
is decomposed by oxyd of mercury, while cobalto-cyanid of potassium 
a no change 
11. belman on ‘Artificial Hyalite and nacre (Academy 
. Sciences, Dec. 4, 1847, L’Institut, No. 727.)—About two years 
ince, Ebelman presented to the French Academy, several products 
ahtaived by exposing silicic ether to moist air: one of these is as trans- 
parent and colorless as quartz crystal; the others have an opaline tint, 
but in water they become as transparent as native hydrophane. The 
> cr mah now presented were of much arger dimensions, and are in 
hemispherical lenses obtained in glass globes; they have 
sana: entire, ee ee the ie Np shrinkage which they 
have suffered. One of these lens-shaped masses is five or six centi- 
metres in ee , it has hardened during a or six months, and the 
molecular movement in it has not yet ceased. 
In mixing silicic athat with colored siaaiealie pepsin various tints 
of wes are imperign to the product. One of the most r arkable of 
ral aventurine,. Exposure to the direct light of the sun, colors the 
Sheeran chlorid of gold, of a blue violet or rose color, remain- 
When the wobg of oa peodamedts in, the.snidatof the ened mass 
_ are very numerous, a green color can be observed in it by 
ay miited light. 
_ The diaphanous silica obtained by silicic ether — be c red to 
the hyalite of mineralogists, which possesses no double “refraction. 
Hyalite is much harder, and the amount of nti it contains does 
exceed +19;, whilst the product obtained by M. Ebelman contains a 
centum of water. The artificial product, however, continues for a 
time to lose water under the influence of a very gentle mo 
pred oe sneer Sa abecweesl that after more than two enond 
seuss geod eaatinn se aeennes Ree ‘ 
ried at 115° PC the diaphanous silica loses its water and becomes 
