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Chemical Notices from Foreign Sources. Jina News,
tion of the solvent, may be considered as either almost
insoluble or as soluble. “But the platinous salts are rarely
met with in analysis, and can be readily converted into
platinic compounds. The presence of platinum in the
first group, to which it does not seem to belong, seems
due to the common phenomena of entanglement. From
the point of view of praical analysis, platinum should be
sought for in the first group, and especially in the second,
where it may be found entirely or in great part along with
mercury. The detection of the metal in the first group
has been already pointed out by authors : to find it in the
second the sulphides of the second group must be treated
with boiling nitric acid diluted at most with an equal
volume of water. Sulphides of mercury and platinum
‘emain unattacked; when dry they are introduced into a
small sublimation tube. On heating we obtain a volatile
ring, sulphide of mercury, and a fixed residue, sulphide of
platinum. We separate these two parts by breaking the
‘ube, and dissolve the mercurial ring in aqua regia. The
xed residue is roasted a few moments to convert it into
metallic platinum, and is then dissolved in aqua regia.
New Method of Transforming Camphor into
Camphen.~-M. J. de Montgolfier.—The camphor after
fusion is treated with sodium at a gentle heat.
Note on Certain Compounds of Titanium. —E-Wehrlin
 and E. Girard.-—Not suitable for abstraction.
Determination of Potassa.—M. A. Carnot.—Reserved
for insertion in full.

Separation of Iron from Chrome and Uranium.—M.
A. Ditte.—The separation of these metals presents certain
difficulties. If we treat the substance under examination
with oxidising agents, 50 as to make the chrome pass into
the state of an alkaline chromate, either in order to determine
 the chromic acid as mercurous chromate, or with a
view to reduce the chromate with hydrochloric acid and
alcohol, precipitating the sesquioxide of chrome afterwards
by means of ammonia, we necessarily introduce alkalies
which it is difficult to get rid of, and whose presence may
be inconvenient in the course of the analysis. As for the
method of separating chromic oxide, by means of ite
solubility in cold potassa, it must be regarded as giving
results scarcely even approximate. In like manner the
Beparation of uranium by carbonate of ammonia, which
ought to dissolve it entirely as uranate of ammonia, is not
easily completed. We succeed better if, after having pre-Cipitated
 the oxides by ammonia, and having calcined them
in a current of hydrogen, we treat Lhe residue with dilute
hydrochloric acid. The iron may be thus removed, but
the protoxide of uranium is not perfectly insoluble in this
acid unless it has been very strongly ignited. It is then
washed, dried, and re-ignited in a current of hydrogen
before weighing. The separation of these oxides may be
effected with great accuracy by operating in the manner
proposed by M. Sainte-Claire Deville for the separation of
iron and alumina. The metals are brought to the state
of sesqui-salts ; all metals whose sulphides are insoluble
in dilute acids are removed by known. methods, and the
ferric, chromic, and uranic oxides are then precipitated
together by an excess of ammonia. Care must be taken
to drive off by ebuliition any free ammonia which might
dissolve a portion of the latter. The oxides are well washed,
calcined, placed in a porcelain tube, and heated to redness
in a current of pure hydrogen. The ferric oxide becomes
metallic iron, the uranic oxide (a mixture of U304 and
U,4Os) is reduced to UO, while the chromic oxide remains
unaltered. This mixture of iron, uranium protoxide, and
chromium sesquioxide is weighed, returned to the tube,
and subniitted to the action of a current of gaseous hydrochloric
 acid at a red heat. The oxides of uranium and
chrome remain entirely unattacked by the acid, and their
weight suffers no variation. As for the iron, it is entirely
volatilised as ferrous chloride, and deposited in white
crystals in a cooler part of the tube. After an hour or an
hour and a half the boat is allowed to cool in a current of
hydrogen intended to drive out the hydrochloric acid from
the tube, and the mixture of chromic oxide and uranous
oxide is weighed, and treated with pure nitric acid. The
protoxide of uranium which remains in the form of a
brown amorphous powder is at once attacked, even in the
cold, with evolution of nitrous fumes and formation of
uranium nitrate, It is well, however, to heat for a few
moments in order to be certain that the chromic oxide
retains no traces of uranium ; the solution is then filtered
off, and the residue calcined and weighed.
Certain Properties of the Sulphides of Platinum
considered from an Analytical Point of View.—M.
J. Ribau.—Platinic sulphide, prepared either in the cold
or at the temperature of the waterbath, and taken alone—
or at any rate in the absence of the metals of the first two
groups—may be considered insoluble in the ammoniacal
sulphides and the alkaline mono- and polysulphides. It
may be placed in the second group along with mercury.
Considerable quantities of platinic sulphide may be dissolved
 by means of well known artifices, such as pouring
a solution of platinic chloride drop by drop into a sulphide,
or melting a mixture of platinic sulphide and dry alkaline
sulphides at redness. Platinic sulphide may be dissolved in
ammoniacal sulphides and alkaline polysulphides in pre:
Bence of metals of the first group,and in quantities the greater
the more such metals are present. Platinic sulphide mixed
with all the metals of the second group is not dissolved by
ammonium monosulphide, but by the trisulphide, though
less than copper. Platinous sulphide, according to its
Physical condition and the nature or degree of sulphuriga-No.

 6, August 6, 1877.
Experimental Researches with the Gases Produced
by the Explosion of Dynamite on various Character.
istics of Meteorites (continuation).—M. Daubree.—
The compression of the air which the meteorite drives
before it produces not merely the heat, the incandescence,
and the luminous train observed in such bodies. This
compression contributes principally to the rupture of the
mass, however tenacious, to the superficial tarnish of each
fragment, and to the partial pulverisation of the substance.
Reply to some of the Objections advanced by M.
Cosson against the Project of the Formation of a
Sabarian Sea.—M. Rouddaire.—An account of the beds
of certain ancient rivers in the Sahara.
Comparative Influence of Leafy Trees and of
Conifers upon the Rainfall andthe Hygrometric Condition
 of the Air,—M. Fautrat.—The author shows that
:onifers, such as the various pines and firs, have a much
greater influence than trees with true leaves. Hence he
‘ecommends the formation of pine-woods in Algeria.
On the Catechins.—Arm. Gautier.—A number of sub"
stances, having among themselves differences and analozies
 of the same order as the tannins which accompany
them, have hitherto been confounded under the name of
catechin. He distinguishes catechin from the yellow
catechu of Bengal, C;;H;308; catechin from a brown
catechu of Pegu, agreeing in formula with the foregoing,
but fusible at a temperature lower by 50° and catechin
from mahogany, Cy2H34016.
Experiments Proving that Chloroform has no
Action either upon the Septicity or the Vibriones in
Putrid Blood.—M. V. Feltz.—Chloroform mixed with
putrid septic blood in the form of vapour, or added direé&tly
to this liquid, has no appreciable effe@ either on ite
vibriones nor on its septicity.

Biedermann's Central-Blatt fiir Agrikultur Chemie,
Heft 4, April, 1877.
Carbonic Acid in “ Ground Air.”—Dr, Port.—Deter.
minations of carbonic acid in the ground-air were made at
Munich at depths of 15 to 3'0 metres. It appears that
he greatest amount of carbonic acid was generally observed
 in the autumn, In most of the stations the prorortion
 of carbonic acid was greater in 1873 than in 1874.