1 88 
SCIENCE. 
CHEMICAL NOTES. 
The Optical Properties of Mixtures of Isomorphous 
Salts. — II. Dufet has verified the law which lie communi- 
cated to the Academy, April 8, 1878, i. e., that a crystal 
formed of a mixture of two isomorphous salts has indices 
of refraction, which vary continuously with its composi- 
tion, so that the variation in the value of the index is 
proportional to the number of equivalents of one of the salts 
introduced into the mixture. 
Influence of Temperature on the Distribution of 
Salts in their Solutions. — In all salts the concentration 
of the heated portion decreases and that of the cold part 
increases. The difference thus established increases with 
the original concentration. In the series of the alkaline 
chlorides the differerence is so much the greater for the 
same absolute concentration as the molecular weight is 
higher. The phenomenon seems to have no relation with 
the curve of solubility. C. Soret. 
Rise of the Zero-point in Mercurial Thermometers. 
— The zero-point rises further and more quickly in ther- 
mometers of “ crystal ” glass than in those free from lead. 
The rise of the zero-point is much more rapid at the outset, 
and tends probably towards a limit for a very prolonged 
heating at a fixed temperature. The effect of an elevated 
temperature renders the thermometer more stable under 
the influence of heat at any lower temperature. 
J. M. Crafts. 
Development by Pressure of Polar Electricity in 
Hemihedral Crystals with Inclined Surfaces. — What- 
ever may be the determining cause, whenever a hemihedral 
non-conducting crystal with inclined surfaces occurs, there is 
a formation of electric poles in a certain direction ; whenever 
the crystal expands the disengagement of electricity takes 
place in an opposite direction. 
MM. Jacques and Pierre Curie. 
Action of Permanganate upon Potassium Cyanide. — 
This reaction produces much nitrite and a little urea in 
an alkaline medium, whilst, if the liquid is acidified with 
sulphuric acid, urea is formed in abundance. The simul- 
taneous formation of two incompatible compounds, urea 
and nitrous acid, under the influence of permanganate, 
shows that the nitrogen of the cyanogen is exposed at once 
to an oxidising action and to hydrogenisation. 
E. Baudrimont. 
Comparative Solubility of Lead Phosphate and 
Arseniate in Dilute Acetic Acid. — One part of lead 
arseniate dissolves in 2703.05 parts of dilute acetic acid at 
38.94 per cent. One part of lead phosphate requires only 
782.90 parts of. the same acid. Armand Bertrand. 
Cause of the Acid Reaction of Animal Tissues 
after Death. — The acid reaction is due to a decomposi- 
tion of the fluids in the tissues effected immediately after 
death by the action of Schizomycetes. At first volatile 
fatty acids appear to be derived from the incipient decom- 
position of the albumen, speedily followed by the two 
lactic acids produced from glycogen. The richer a tissue 
in carbohydrates, the longer this acid reaction prevails 
after death, as in the liver, the muscles and the lungs. 
It is briefest and faintest in the pancreas. In the later 
hours of putrefaction, the lactic acids disappear and .are 
succeeded by succinic acid. Sooner or later an alkaline 
reaction sets in throughout the tissues, much ammonia be- 
ing evolved from the decomposition of the albumen. 
Marie Ekunina. 
Constitution of the Salts of Rosanaline and of 
Analogous Coloring-Matters. — If rosaniline is a triami- 
dic aromatic carbinol its salts will be of two classes : the 
first series is to be regarded as the ether of a tertiary 
aromatic alcohol ; the second series comprises the salts of 
this ether, which is itself a triacid amine. 
A. Rosentiehl. 
Resin of Palisander Wood. — A. Terreil and A. Wolff 
ascribe to this resin the composition — C21H21O8. It is very 
soluble in alcohol in all proportions, less soluble in ether, 
chloroform, and carbon disulphide, and insoluble in water. 
Nitric acid transforms it into an acid, which crystallizes 
in very fine orange-yellow needles, united in tufts. 
Solubility of Recently Precipitated Carbonate of 
Lime in Ammoniacai. Salts in Presence of an Equivalent 
Proportion of Sodium Chloride. — At the temperature of 
10 to dissolve 1 grm. calcium carbonate there are required : 
Ammonium hydrochlorate 13 980 grms. 
sulphate 8.380 “ 
nitrate 14.438 “ 
Armand Bertrand. 
Purification and Refining of Fatty Matters. — 
To determine whether an oil is pure, M. Octave Allaire 
takes a piece of carbonate of soda (crystal), the size of a 
nut, dissolves it in its own bulk of water, and shakes it up 
with the oil under examination in a bottle. If the oil be- 
comes turbid, and gives, on settling, a solid bulky deposit, 
it has been badly purified. Oils which act upon the metal 
of lamps and form deposits of verdigris are also to be re- 
jected as impure. Commercial samples often contain jo to 
15 per cent, of free oleic acid. 
Remarks on the Platinum Sulphocyanide of V. Mar- 
cagno. — This body is not a platinum sulphocyanide, but a 
potassium platino-sulphocyanide, having in its anhydrous 
state been long ago analysed by M. Buckton. Nor does it 
yield a proof of the octo-atomicity of platinum, which in 
this case, as in many others, is tetraiomic. 
G. Wyrouboff. 
A Compound of Titanium Tetrachloride and Acetyle 
Chloride. — On mixing these two bodies the compound in 
question is immediately precipitated in small yellow bril- 
liant spangles resembling lead iodide. On exposure to 
moisture these crystals undergo a change, liberating hydro- 
chloric acid. They may be preserved in dry air, or pre- 
ferably in dry hydrochloric acid. They melt at 25° to 30° 
and crystallize on cooling. In contact with alkaline solu- 
tions they are decomposed, forming an alkaline acetate and 
chloride, titanic acid which is precipitated, and water. The 
analysis of the crystals yielded results agreeing with the 
formula C2H 3 OCl+TiCl 4 . Armand Bertrand. 
Certain Properties of Mixtures of Methyl Cyanide 
with Common Alcohol and Methylic Alcohol. — In 
order to separate methyl cyanide from alcohol it is neces- 
sary to submit the mixture to fractional distillation in order 
to classify the products ; then to dissolve the largest possi- 
ble quantity of calcium chloride in the mixture, boiling at 
the lowest temperature in order to absorb the alcohol ; then 
to distil again in the water-bath, and to submit again the 
product thus obtained lo fractional distillation. A very rich 
cyanide is thus obtained, from which the last traces of 
alcohol are eliminated by distillation over a small quantity 
of phosphoric anhydride, and by rectification to remove the 
small quantity of ethyl oxide and acetate which arise from 
the reaction of the phosphoric acid. 
C. Vincent and B. Delachanal. 
Determination of Urea by Sodium Hypobromite. — 
C. Mehu criticises the memoirs of M. Fauconnier and 
M. Jay ( Bulletin de la Soc. Chimique, xxxiii., pp. 102 and 
105). In opposition to the former of these chemists he 
finds that the presence of cane-sugar distinctly augments 
the quantity of nitrogen evolved from urea by means of 
sodium hypobromite. In opposition to M. Jay he considers 
that it is easy to meet with starch syrups, which give off 
merely an insignificant quantity of ammonia if heated with 
caustic soda. 
A sealed paper from the firm of Scheurer-Rott, opened at 
the last session of l’Academie des Sciences, refers to an 
improvement in alizarin steam reds, by printing upon 
pieces previously prepared with emulsive oil, mixed in 
certain cases with hypochlorite of soda. For producing 
cadmium sulphide directly upon the fibre, M. Schmid 
prints a mixture of arsenious acid, sulphur, sodium acetate, 
and cadmium nitrate. A fine yellow is obtained by steam- 
ing for 1 to 2 hours and an orange is produced by increasing 
the sodium acetate. 
A paper by M. Ziegler was opened, recommending an 
addition of arsenic or boracic acid to the colour beck in 
dyeing madder reds and roses. 
