Rodolfo Amedeo Lanciani.

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lium in its compounds with potassium and sodium is not sufficient
to decide the question. When thallic sesquioxyd is heated with a
solution of iodic acid, a normal dithallio salt is formed, which has
the formula TlflOjk-l-Saq. The sesquioxyd dissolves easily and
completely in cnlornydric acid, forming a colorless solution, which
after addition of potassic or anmiomc chlorid yields beautiful
CTvstals. The new salts, respectively TlClj,6kCl+4aq. and
TlCLyeNH^Cl+iaq., form large colorless transparent crystals,
which resemble combinations of the cube, octahedron and dodeca-
hedron, but which really belong to the square prismatic system.
They are not decomposed by water, even on boiling. With bro-
mine and potassic bromid, and iodine and potassic iodid, thallium
forms the salts, TlBrg,8KBr-f-3aq. and TU j,8KI+3aq., which crys-
tallize in regular octahedra. Kammelsberg remarks that uie
thallium atom, Tl=204, can hardly be regarded as other than
monatomic, but as the double atom of the molecule in the dithal-
lic compounds is hexatomic, the single atom would have to be
considered as tetratomic. The specific heat of thallium is an evi-
dence that the metal is Tl=204, but the isomorphism of two monr
atomic with one diatomic atom has been established in so *many
cases that no certain conclusion can be drawn fi*om the isomor-
phism of thallium with potassium and sodium. It seems probable
that the question can only be settled by determinations of vapor
density. — Berichte der JJeutschen Chemischen OeseUschcrft^ Jahr-
gangy 3, No. 7, p. 360. w. G.

4. On a new method for the volumetric estimation of copper, —
Wbil has given a new method for the determination of copper
which appears deserving of attention. It is based upon the fol-
lowing facts. At a boiUne heat and in presence of an exaess of
firee chlorhydric acid the least trace of cupric chlorid communi-
cates a very distinct greenish yellow tint to the solution. This
tint is the more intense the greater the quantity of acid present.
Stannous chlorid instantly reduces under these circumstances cu-
pric chlorid to colorless soluble cuprous chlorid.

2€uCl, -f SnCl, = eujjCla + SnCl^.
The reaction is finished when the green solution of cupric chlorid
is completely decolorized. A single drop of stannous chlorid in
excess is easily detected by a (frop of mercuric chlorid, which
gives a precipitate of calomel When the solution contains iron
m the form of sesquioxyd as well as copper, the volume of the



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Physics <md Chemistry. 109

solution of tin employed will indicate the sum of the copper and
iron. In this case the author precipitates the copper in another
portion of the assay by means of zinc coupled with platinum, and
then determines the iron by means of potassic hypermanganate.
The copper is then easily foimd bjr difference. The author deter-
mines tne litre of his solution or tin by means of pure metallic
copper, and preserves it from oxydation under a layer of petrole-
um. It is of course necessary that the solution of copper should
be perfectly free from nitric acid. — Comptes HenduSy Ixx, p. 997.

w, G.

5. Ont?ie utilization of the secondary products obtained in the
manufacture of chloral, — Dr. A. W. Hofmann has examined a
mixture of secondary products obtained during the manufacture of
chloral, and con^ensea during cold weather. The liquid began to
boil at 17**-18°, rising slowly to 30°-31°, where the temperature
remained constant a snort time, and then rising again to 50^, when
nearlj^ all distilled over. The most volatile portions were mixed
with three times their volume of alcohol saturated at 0° with am-
monia and heated in a water bath for an hour. The liquid was
then filtered to separate crystals of sal-ammoniac and the alcohol
ammonia and chlorinated ethylic chlorids distilled off The mass
of chlorhydrates of ethyl-ammonias remaining were decomposed
with caustic soda, and the separated liquid alkalies dehydrated by
caustic soda, and finally distuled. In this manner 5 litfes of the
secondary products operated|on gave 1^ liters of a mixture of an-
hydrous ethylamines. These could be separated from each other
bv means of oxalic ether, in the manner already pointed out by
Hofriann. The results of this investigation are interesting, from
the prospect which they afford of obtaming the ethyl-ammonias as
an article of conmierce, at a reasonable price, and m comparative
abundance. — Comptes Bendus^ Ixx, p. 906. w. g.

6. On the nature of the secondary products obtained in the man-
ufacture of chloral. — Kbamer has studied the other products of
the action of chlorine upon alcohol, the existence of a large quan-
tity of ethylic chlorid having been shown by Hofinann. As the
ethylic chlorid was in contact with an excess of chlorine, it was
natural to expect to find in the less volatile oily products the
whole series of chlorinated ethylic chlorids described by Regnault,
and experiment showed that several of these substances were pres-
ent. The most volatile product boiling at 60°, proved to be chlo-
rinated chlorethyl or chlorethyliden, -GjH^Cl^, identical with the
ohlorethyliden prepared from aldehyd. A liquid boiling at 85°,
proved to be ethylen-dichlorid, the formation of which by the ao-
tion of chlorine upon ethylic chlorid had not before been observed.
The next product was chlorinated ethylen dichlorid -GjELCl . CL
boiling at 115**, and the last bichlorinated ethylen, CJjHjClj, boil-
ing at 37°. Other chlorinated products were also observed, but
not yet studied. To prove the identity of the chlorethyliden ob-
tained in this manner with that obtained from aldehyd by the ac-
tion of phosphoric pentachlorid, Kr&mer heated a portion of it



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110 Scientific Intelligence.

with alcoholic ammonia to 160^ for 12 hours. In this manner an
oily base boiling at 1 80**-l 82°, and having the characteristic odor
of collidine, -CgU nN, was obtained. This base had already been
formed from aldeh^d-ammonia by Bsyer, and found to be identi-
cal with that obtamed by Anderson from animal oiL — Berichte
der DetUechen Chemisehen QeselUchq/ty Jahrffang^ 8, p. 267-262.

w. G.
7. On %ome proj^erties of iron precipUated by the galvanic cur-
rent, — Lbnz has given some interesting particulars in relation to
the composition and properties of iron as precipitated in the me-
tallic form by the battery. The iron examined was deposited by
Klein^s process from a solution of the mixed sulphates of iron and
magnesium. Weak currents were employed, and the solution was
kept neutral by carbonate of magnesia. Iron so tjjirown down has
a beautiful fine-granular structure, showing no traces of crystals
under the microscope. Its color is a soft bright gray. Its hard-
ness is very remarkable — not less than 5*6 of the ordinary mineral
scale, and it is excessively brittle, so that it may be rubbed to
powder between the fingers. When the iron is slowly reduced
upon a polished surface, it is free from flaws and has a velvetv
look. As it becomes thicker, bubbles or pits are formed as small
oval depressions. When heated over a fire the iron loses many of
these properties in a remarkable degree. Its hardness diminishes
and becomes 4*5 ; its brittleness entirely disappears, and it be-
comes so nexible and tenacious that it cannot oe broken by re-
peated bendinff or even bv folding and strongly smoothing down
the folds. When heated m vacuo the iron changes color and be-
comes almost as white as worked platinum. The ienited iron rusts
very quickly both in air and in previously boiled watery this is
not the case with the metal before ignition. In the electric series
unignited iron stands nearer to copper than the ignited metaL
On analysis by means of SprengePs pump, the precipitated iron
was found to contain various eases — ^vapor of water, mtrogen, car-
bonic oxyd, carbonic acid and hydrogen. Levv thinks Siat the
carbonic acid came from the solution nrom which the iron was pre-
cipitated, and that the carbonic oxyd was formed during the igni-
tion of the tube containing the iron in the process of uialysb ;
also that the vapor of water was formed by the union of hydrogen
with the oxygen of a small amount of rust in the iron, since it was
only given off at 1,600° C. The hydrogen in the iron was always
in largest quantity ; the whole quantity of gas varied greatly, and
sometimes amounted to 185 times the volume of the iron. The
absorption of the gases was found to take place mainly in the first
layers formed. Cm warming the reducea iron, the evolution of
gas began at temperatures below 100°, but at this temperature
chiefly hydrogen was evolved. Ignitea galvanically reduced iron
decomposes water and absorbs the firee hydrogen either wholly or
partially. — BvUetin de P Aoadimie de Piterebourfj xiv, p. 337,
eited in Dingier* % Pofytechniechee Journal, cxcvi, p. 44. w. o.



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Physics and Chemistry, 111

8. On ths preparaiion of barium chlorate, — ^Brandau has pro-
posed the following simple method for the preparation of banum
chlorate: Commercial crystallized aluminum sulphate, sulphuric
acid, and potassium chlorate, in the ratio of one molecule of each of
the two former to two of the latter, are mixed with water to the
consistence of a thin paste, wanned for half an hour on the water-
bath, allowed to cool completely, and treated with alcohol in excess.
Upon filtering, and neutralizing with barium hydrate, barium sul-
phate and some aluminum hydrate are precipitated, and barium
chlorate remains in solution. The alcohol is distilled off, and the
filtrate on evaporation yields crystals of the pure barium chlbrate.
The only precaution necessary is to have the aluminum sulphate
and the pulphuric acid in slight excess. — Ann, Ch, Fharm,^ cli, 861,
Sept. 1869. G. p. B.

9. On tJ^ properties of Selenium, — Rathke has investigated, in
the Halle laboratory, the various modifications which selenium,
like sulphur, is capable of assuming. Notwithstanding the differ-
ence in the behavior of the various forms of each, respectively,
to solvents, especially €Sg, Rathke places the insoluble black se-
lenium with the rhombic variety of sulphur, and the red amor-
phous selenium with the insoluble amorphous form of sulphur. As
in the case of sulphur, the latter variety of selenium is produced
by the decomposition of selendithionates (solutions of selenium in
alkaline sulphites) by acids ; by the action of water on selenium
chlorid ; and by tne sudden cooling of fused selenium. So on the
other hand, by the slow decomposition of a solution of potassium
selenid, distinct crystals of black selenium are produced, precisely
as when by the similar decomposition of alkaline sulphids, lar^e
rhombic crystals of sulphur separate. Though red selenium is
more stable than the corresponding form of sulphur, yet, like this,
it passes into the other variety on raising the temperature to lOO^'
C., with a distinct evolution of heat. The specific gravity of selen-
ium in these forms, is as follows : For the black variety, 4*80 to
4*81 ; the red, crystallized from carbon disulphid, (and correspond-
ing tomonoclinic sulphur,) 4*46 to 4*51, the red, amorphous, 4*26.
Agreeing here, also, with the corresponding forms oi sulphur, as
already given. Regarding the behavior of selenium toward carbon
disulphid as exceptional, Kathke tried the action of other solvents.
Sulphur chlorid saturated with selenium with the aid of heat, de-
posits on cooling, crystals of sulphur, leaving selenium chlorid, in
which selenium dissolves freely, forming when cold a syrupy liquid,
from which, on standing, the black variety of selenium separated
in small nodules. The solubility of rhombic (octahedral) sulphur
in carbon disulphid, led to the supposition that selenium might be
equally soluble in carbon diselenid. Various methods for prepar-
ing this substance were tried, but, though small quantities were
obtained by acting on selenium phosphid with moist vapor of car-
bon tetrachlorid, heated in a tube, sufficient for the above purpose
could not be obtained. Carbon tetrachlorid itself, does not dis-
solve .the black variety of selenium, selenium-ethyl dissolves both.



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112 Scientific Intelligence.

but in very small quantity. Of the solvents tried, only those which
were selenium-compounds dissolved black selenium.

Rathke also examined the compounds which sulphur forms with
selenium, hoping to throw some light upon their mutual iso-dimorph-
ism. He first melted the substances together in the ratio of one
atom of selenium to two of sulphur, repeatedly extracted the re-
sulting mass with carbon disulphid, and crystallized out the por^
tion dissolved in fractions. The crystals, however, increased pro-
gressively in sulphur and diminished in selenium. The precipitate
obtained when sulphydric gas and selenium dioxyd gas act up-
on esPch other in solution, was then examined. By solution m
carbon disulphid and evaporation, well-formed rhombic prisms, in
color like potassium dichromate, were obtained, which gave on
analysis 63*86 per cent selenium and 36-60 per cent sulphur. These
crystals, then, though by no means a mixture of the constituents,
do not correspond m composition to the formula SeS,, which re-
quires 66*42 per cent Se and 44*68 per cent S. The process was
then reversed, and the precipitate produced when selenhydric gas
reacts upon sulphur dioxyd collected and treated as above. It
contained considerable black selenium, not taken up by the solvent.
On fractionally crystallizing, three products were obtained, one
(c) soluble in 67 parts €JSj, the second (d) in 263 parts, and the
third (a) considerably more so than selenium itself (a) consisted
of minute dark ruby-red, rounded crystals ; (6) of brilliant-red
prisms ; and (o) of orange-red tabular prisms. On analysis, (a)
was found to agree nearly with the formula Se jS ; but (ft) and (e)
were intermediate between Se^Sand Se9,. Rathke regards them
as isomorphous mixtures.

Carbon diselenid €Seg was prepared but only in small quantity,
not even sufficient for analysis. It appeared as a thin, brilliant-
brown liquid, of peculiar and disagreeable odor, recalling at first,
when dilute, that of carbon disulphid, but being when concen-
trated, verv pungent and irritating to the eyes. It burned with
tfie Wue selenium flame, was not very volatile, and was insoluble
in all solvents tried. At the same time there was formed ethyl

selenxanthate, -GSe _ and potassium selenxanthate, €Se : _ .

Rathke also also attempted the production of selenium tetra-ethyd
but succeeded in getting only tri-ethylselenin chlorid Se {€^
H 5)301, in combination with zinc chlond, and also with platinum
chlorid. — Ann. Gh, Phartn.y clii, 181, Nov. 1869. g. p. b.

10. On the vrepa/ration of nitrogen pentoxyd {nitric anhydrid,)
— Odet and Vignon employ for this purpose a double U tube, in
each bend of which 140 to 160 grams of silver nitrate is placed,
the whole being heated to a temperature of 60° C. Phosphoryl
chlorid (POOL ) is allowed to fall drop by drop, into the first leg
of the tube. The nitryl chlorid (NOjCl) thus produced, reacts up-
on the silver nitrate in the second bend, to which is attached, by
melting, a receiver, in which the product of the reaction collects.



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Physics and Chemistry. , 118

This receiver is immersed in a freezing mixture. No disengage-
ment of oxygen takes place, silver phosphate and chlorid be-
ing the only secondary products. The reactions are as follows : —

(1) Sg ' f ^)»+ (P^) Cla= if, [ ^» + (Ne.Cl),.

(2) A^ » [ ^ + (Ne,)Cl = NO^ } ^ + AgCl.

— Comptes BendtiSy bdx, 1142. * g. p. b.

11. On a new method for preparing bromhydrie acid, — Cham-
pion and Pkllkt describe a new and simple mode of preparing
bromhydrie acid by the action of bromine upon paraffin at a mod-
erately elevated temperature. Two retorts are employed, one for
the bromine, the other for the paraffin. The neck of the first re-
tort is prolonged and bent at right angles so as to enter the tubu-
lure of the second — being fixed there by a ground ioint — termi-
nating near the bottom, ^y means of a sand or oil-bath, the pa-
raffin is kept at a temperature of 180° C. and by a saline bath the
bromine is maintained at 65° C. As the bromine gradually distils
over into the paraffin, the bromhydrie acid gas is evolved, and af-
ter passing through a bulb tube containing water, and a U tube
filled with broken glass and bits of moistened phosphorus, to re-
move any traces of unchanged bromine, it is collected in the liquid
to be saturated with it, placed in a vessel surrounded with ice.
The aqueous solution thus obtained satui»ted at 0° C. has a density
of 1*78, and coiTcsponds to the fonnula HBr, H^O. Each c. c.
contains 1'46 grms. HBr. — £uU. Soc, Ch.^ II, xiii, 197, March, 1870.

G. p. B.

12. On the recovery of Uranium Jrom the Phosphate. — In using
a solution of uranium K)r determining volumetrically phosphoric
acid, residues of uranium phosphate are obtained, from which it is
desirable to recover the uranmm. Two methods for doing this
have been lately proposed. The first hy Heintz, obtains the ura-
nium as nitrate. Tne phosphate, previously washed, dried and
weighed, is dissolved in nitric acid. Half as much pure tin is
weighed out, and nine-tenths of it added to the nitnc solution,
which is then heated until the tin is entirely converted into stan-
nic hydrate ; if, in this solution, ammonia gives a precipitate not
entirely soluble in acetic acid, the rest of the tin is added, and the
process repeated. All the phosphoric acid is contained in the pre-
cipitate. The filtrate is diluted, treated with sulphydric gas to
precipitate the last traces of tin, again filtered, ana evaporated to
crystallization.

The second method, proposed by Reichabdt, consists in dissolv-
ing the uranium residues in either nitric or chlorhydric acid, adding
an excess of ferric chlorid, making the solution acid with acetic
acid by adding sodium acetate, and after considerable dilution,
heating to boiling. All the phosphonc acid, together with the
excess of iron, is thus precipitated. Instead of boiling the solu-
tion after the addition of the ferric chlorid, it may be treated with

Am. Joub. Sci.— Sboond Sbbibs, Vol. L, No. 14a— July, 1870.
8



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114 SderUific Intelligence.

an excess of sodium carbonate, and filtered. In presence of free
carbonic acid, the sodium carbonate holds the uranium in solution,
the phosphoric acid being precipitated with the iron. The filtrate
from eitner of these methods is acidulated with chlorhydric acid,
and after boiling to expel the carbonic, gas, the uranium oxyd is
precipitated with ammonia. — Ann, Ch, Phami.^ cli, 216, Aug. 1869.
^eitachr. analyt. Chem.y 1869, 116. g. p. a

13. On the modifications of atdphur trioxyd {sulphuric anhy^
drid.) — Schultz-Sellack has examined the isomeric modifications
of sulphur trioxyd. It was prepared by distillation from di-snl-
phuric acid (fuming,) the vapors being rendered anhydrous by
passing them over phosphoric anhydrid. On cooling the liquid
thus obtained, the thermometer immersed in it is observed to be-
come stationary at 16° C, the fluid solidifying in long transparent
prisms. These melt again at the same temperature, the liquid be-
mg obtained again, frequently unaltered. Sometimes, however,
white flocks remain in the melted mass, which gradually collect in
warty masses of fine white needles, until the entire liquid has be-
come a matted n^ss of theuL The same change takes place when
the liquid is kept for some time at a temperature below 25** C;
above 27° C, however, it does not take place. The solid anhydrid
thus produced becomes gradualljr fluid again when the tempera-
ture rises to above 60° C; but this solidification and liquefaction is
not a freezing and melting, in the ordinary sense of these terms,
since both take place graaually, within certain definite ranges of
temperature. Tiie fluid anhydrid has a remarkably high coefficient
of expansion by heat ; being for temperatures between 26° and
46°, 0*0027 for each degree, more than two-thirds that of the gases.
It boils at 46° C. under a pressure of 760"*'° •; at 20° its vapor-
tension is 200™™. In a vacuum the first modification shows no
vapor-tension; but gradually vapor is evolved, so that after seve-
ral days, a tension of 30 or 40™™* at 20° is obtained. The vapor
of the solid as well as that of the fluid trioxyd has a normal den-
sity, found to be 2*74 to 2*76; SOg requires 2*76. From the
shove facts, the author concludes that sulphur trioxyd exists in
two states : 1st, a Sulphuric anhydrid solidifying at +16° in long
colorless prisms, whicn melt at the same temperature ; boiling at
46° C. 2d. I? Sulphuric anhydrid, produced from the former, at
temperatures below 26°, in very fine needles ; becoming at temper-
atures above 60° gradually fiuid again, being transformed into « ;
yielding vapor very slowly at ordinary temperatures, which is like
that given by «, but has a less tension. He regards <? as a polymer
of o, since many poljrmeric organic compounds, as, for example,
cyanuric acid, show similar variations in physical properties, as
their molecules are more condensed. — Ber. JBerL Chem, Oes.^ iii,
216, March, 1870. g. p. b.

14. On t?^ conversion of isolmtyl alcohol inU> tertiary pseudo4mtt/l
alcohol — ^From purely theoretical considerations, Mabkownikopf
was led to believe that isobutyl alcohol (that produced during
fermentation) by the loss of water, or its iodia by the loss of



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Physics and Chemistry. 115

hydriodio acid, woald give a bntylene identical with the isobn-
tylene of Butlerow. By heating isobutyl iodid with alcoholic
potash, a butjrlene was obtained, which united directly with hy-
driodic acid, giving a butyl iodid having the boiling point of ter-
tiary pseudo-butyl iodid. On treating this with moist silver oxyd,
tri-methyl-carbinol (tertiary pseudo-but^ alcohol) was obtained
with its very characteristic properties. The reaction which takes
place is as K>llows :

(1) €H -.m= € (2) £) +HL= €1

'€H,€H3 €H3€H3 €H3€H, €H^€H^

'3' ^^-^1 - ^-^"*y^- butyflSd.

Morkownikoff believes that these facts sustain his general law of
the formation of unsaturated compounds; a law which for the
homologues of ethylene may thus be formulated: WTien tocUer
is removed J¥om an alcohol-molecule^ that carbonrOitom which
is directlg united with the carbon-atom holding the hydroxyl^
furnish the hydrogen. A similar law holds in the case of the
haloid anhydnds of the monatomic alcohols. When combination
takes place between an unsymmetricaUy constituted homologue
of ethylene (for example, propylene CJHgCJH^H^) and water (or
an hcUoid acid\ the residues into which these latter bodies are
stparatedj are divided between the two carbon-atoms so that the
hydroxyl {or the corresponding halogen)^ is united to the least
hudrogenized carbon-atom in the compound. — Zeitschr. Chem.^ II,
VI, 29, Dec, 1869. G. P. B.

16. On the Synthesis of AromcUic Acids. — Starting from the
well known facts that a monobasic acid may be viewed as a
hydrocarbon in which an atom of hydrogen is replaced by carboxyl
reOOH), and further, that, in general, the basicity of acids
oepends upon the number of carboxyl groups which they contain,
^Wttbtz proposes to make practical use of tnem in synthesis. By
effecting one or more such replacements in a hydrocarbon, eitner
by the carboxyl group itself or its ethyl-derivative (■GOO("e2H5)),
— which can be effected by heating the corresponding bromine
derivative of the next lower homologous hydrocarbon with ethyl
chlorocarbonate and sodium -amalgam, — any desired aromatic
acid may be produced. In this way, for example, Wurtz prepared
benzoic acid; 90 grams monobromo-benzol (phenyl bromid, "GeH.
Br) being heated with 60 grams ethyl chlorocarbonate (€JOO
{€} 2^^)01) and 8*5 kilo^ams sodium-amalgam containing one
per cent of sodium. The action procee&d slowly, requiring
many days for completion, even at 110° C. Carbonic and carbon-
ous gases were evolved, sometimes mixed with a gas which burned
with a green flame, probably ethyl chlorid. When the fluid had
entirely disappeared and the mercurv had again recovered its
mobilitv, the saline mass was extracted with eSiei*, and the ether
distilled off till the temperature rose to 150° C. The residue, which



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