Crm oe} Chemical Notices from Foreign Sources.
bonate and precipitated with potash-alum, likewise gives autoclave for several hours. The pressure rises to 30—35
, very rich lake. These lakes resist elevated tempera- itmospheres. The produ of the reaction, distilled with
ures and sulphurous emanations, and may be used in the in alkali, is filtered to separate the base of the violet; the
solouration, in the mass, of vulcanised india-rubber, with-  iltrate containing the base of the green is then treated
standing perfe@ly the degree of temperature required for with an acid and a salt of zinc to form the corresponding
sulcanisation and the disengagement of sulphuretted hy- louble salt of aniline-green and of zinc, and the colouring
drogen which ensues during the reaction. The colours matter is then precipitated by means of common salt. If
obtained with these lakes are in this case incomparably -osaniline is substituted for methylaniline violet, we obtain
Gner than the shades obtained with mercuric sulphide the colouring matter known as Hofmann’s violet, hitherto
(vermilion) and antimonic sulphide, and may serve as orepared by the aGion of methyl iodide upon rosaniline
substitutes for these colours in painting, and have the aydrochlorate. What has been said of the preparation of
advantage of being harmless. Pure fluorescein likewise methyl chloride applies equally to the preparation of the
forms a yellow lake with hydrated zinc oxide. If eosin other chlorides of alcohol radicals, modifying the condiand
 fluorescein are employed conjointly they yield tions of pressure and temperature. Ethyl chloride ads in
lakes capable of replacing the reds and oranges ob- ‘he same manner as methyl chloride upon methylaniline
tained from lead, as minium, orange minium, &c. violet and upon rosaniline hydrochlorate, and is prepared
Zinc chromate, if treated with a potassic solution of eosin under the same conditions. The yield of ethyl chloride
and the eosic acid liberated by the addition of alum, is 6o per cent of the theoretical quantity.
yields, on evaporation to dryness, lakes remarkable for
the brightness of their shades, which may range from a
sale yellow to a lively red, and which may serve as substitutes
 for the poisonous chromates of lead. These pro-1u@s,
 although attacked by water, may be advantageously
zmployed in painting, for they are absolutely indecomsosable
 by oils and essences, cover well, and can be presared
 cheaply. With the aid of these new colours and
~ertain others, the author has reproduced approximately,
with-non-poisonous colours, the chromatic table of M.
Chevreul.
A&ion of the Oxychloride of Carbon upon Toluene
inpresence of Aluminic Chloride.—MM. E.Adorand J.
M. Crafts.—The authors find that in consequence of this
action hydrogen is removed not from the methyl group
but from the radical CgHs, aceton being obtained as a final
product.
Remarks on the Action of Stable Anhydrous Acids
upon Stable Anhydrous Bases: Explosion of the
Compound.—MM. E. Solvay and R. Lucion.—The
authors observe that a mixture of anhydrous phosphoric
acid with anhydrous oxide of sodium may remain without
-eaction at the ordinary temperature, but an elevation of
:emperature to 100° determines instant combination with
-emarkable violence, amounting in one instance to explosion.
 This instantaneous character of the combination
axcludes, they consider, the hypothesis of the presence of
a trace of water in M. Béchamp’s experiments on the
same subje&. M. Lucion objects, however, to the inferance
 drawn by M. Béchamp from these phenomena.
Maturation and Diseases of the Cheese of the
Cantal.—M. E. Duclaux.—The principal fa&t in the
sipening of the cheeses of Cantal, and, without doubt, of
many others, is the gradual transformation of the casein
insoluble in water into two albumens soluble in that
liquid. The large amount of water in Cantal cheese (45
per cent) gives opportunity for the sugar of milk remaining
 in the curd to undergo fermentation, sometimes alco-1olic,
 more commonly lactic, with a great tendency to
hecome butyric.
Measurement of the Diedric Angles of Microscopic
 Crystals.—M. Em. Bertrand.—Not suitable for
abstraction.
Preparation of Alcoholic Chlorides, and their Application
 to the Production of Colouring Substances.
—MM. P. Monnet and F. Reverdin.—The green colouring
 matter known in commerce under the name of methylaniline
 green was prepared hitherto by causing the nitrate
of methyl to a& upon an alcoholic and alkaline solution
of methylaniline violet. The fads which the preparation
and the industrial employment of methyl-nitrate present
have led the authors to search for another method. They
have, since March, 1874, caused methyl chloride to act
apon methylaniline violetin an alkaline alcoholic solution.
They produce methyl chloride by heating a mixture of one
molecule of methylic alcohol and one molecule of hydro-“hloric
 acid (commercial acid at 23° B.) to 100° in a closed

Bulletin de la Societe Chimique de Paris,
No. 12, December 20, 1877.
Thermic Formation of Isomeric Bodies.—M. Berhelot.—The
 experiments described, which have been exended
 to about thirty compounds, including alcohols,
aldehyds, fatty acids and their salts, acid chlorides and
bromides,? sulpho-conjugated acids, &ec,, conduct to this
‘mportant conclusion : isomeric bodies of the same
~hemical function are formed from their elements with
lisengagements of heat almost equal; thus their reciprocal
 metamorphosis liberates very little heat. Finally,
the same relations exist in the formation of their isomeric
derivatives.
New Remarks on the Quantities of Heat Liberated
on Mixing Water with Sulphuric Acid.—M. Berthelot.—Already
 noticed.
Limits of Etherification.—M. Berthelot.—The expeiments
 described verify the general laws of etherification,
and especially the identity of the limits of combination
between the acids and the alcohols from the ordinary
temperature up to 260°
Heat Liberated by Chemical@ombinations in the
Jaseous State: Anhydrous Acids and Water.—M.
Berthelot.—A thermo-chemical study of the synthesis of
aitric acid. The author remarks that the reactions which
ie describes, so simple for those who write water HO,
and the anhydrous acids NOs and C,H303=2 vols, become
 complicated in the atomic notation. It is not one of
‘he smallest inconveniences of this notation to have made
disappear from the science the simple notion of anhydrous
acids and anhydrous bases ; that is to say, to suppress or
zomplicate an entire order of positive facts and of rela-‘ations
 given by experience, because the new language
was unable to express them.
Researches on Chloral and on its Hydrate.—M.,
Berthelot.—There is liberation of heat in the reaction of
gaseous chloral upon gaseous water with formation of a
jaseous compound. ‘The gaseous hydrate of chloral exsts
 then veritably as a compound distin from a mere
mixture of the two vapours. This conclusion is conformible
 to the results obtained by M. Troost from the study
>f the temsions of dissociation. It is supported by this
fact that anhydrous chloral does not combine instan--aneously
 with water, but condenses in it first in the form
of an oil which only dissolves by degrees even on agita-:ion
 ; whilst, on the contrary, chloral hydrate in vapour
condenses under water in the state of a crystalline
hydrate, if not agitated, and dissolves at once on stirring,
Physical Properties of Quercite.—L. Prunier.—An
account of the crystalline form, rotatory power, specific
gravity, and solubility of this compound.
Synthesis of Indol.—M. Maurice Prudhomme.—In
1873 the author obtained indol by setting out from the
sases obtained by Hofmann by the action of bibromide of