26. On some Chlorides of Platina, by G. Magnus.-The protochloride is obtained by heating the perchloride to the temperature of melting lead. If it be pure, it is insoluble in water; but if the perchloride from which it has been obtained was not sufficiently heated, the residue dissolves in water, with such a dark brown colour, that the liquid, although clear, appears entirely opaque: it is a solution of the protochloride in the perchloride. On evaporating, a brown powder is precipitated, which does not dissolve again in water, when the water in which it was suspended is removed; but on adding this to water, the brown precipitate is redissolved by heat. This precipitate is distinguished from the protochloride obtained by heat, by its colour, and particularly by its greater solubility in muriatic acid; nevertheless, the composition is precisely the same, for, decomposed by hydrogen, it leaves the same quantity of metal, 26.41 per cent.

The proportion of the protochloride dissolved by the perchloride depends on the dilution of the solution. After evaporation to dryness, the residue may be redissolved by continued ebullition ; but if cold water be employed, only a very small quantity of the protochloride dissolves in the perchloride. By repeating the same series of operations frequently, the solution becomes more and more freed from the protochloride it contained. The brown chloride of platina dissolves in muriatic acid, with a particular red colour, and so plentifully, that it might be imagined a combination was formed similar to those that Boullay has pointed out between muriatic acid or hydriodic acid, and other chlorides and metallic iodides.

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If chloride of potassium be added to this solution, an acid salt is obtained in prismatic crystals, which, analyzed by hydrogen, affords,

or one atom of protochloride of platina, and one atom of chloride of potassium. This salt is very soluble in water, but not in alcohol. The double salt of potassa, and that of ammonia, is obtained in the same manner. The first does not crystallize in water, and is very soluble in alcohol; the second crystallizes, on the contrary, very easily in deep red crystals.

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If to a solution of the protochloride in muriatic acid ammonia be added in excess, at the end of some time there is precipitated a green salt, crystalline, insoluble in water, alcohol, and even muriatic acid. It is composed of one atom of protochloride of platina, and "one atom of ammonia, or of

It has been analyzed, by decomposing it with carbonate of soda.Ann. de Chimie, Janvier.

-Hem to s 1990 § III. NATURAL HISTORY, &c.

9bilo Effect of Chlorine as an Antidote to Hydrocyanic Acid. The following is abstracted from a letter by M. Dauvergne to M. Gay Lussac, describing an experiment made by himself and M. Siméon. Two drops of hydrocyanic acid were put into the end of a glass tube, and introduced into the lachrymal gland of a cat; contractions immediately came on, followed by strong tetanic convulsions; an abundant salivation took place, producing, through hard breathing, a thick -white froth. The pulsations of the heart were quick, irregular, and extensive, as if each were the last effort of life. Inspiration was difficult and painful; expiration, frequent, prompt, and forcible. Notwithstanding this desperate state of the animal, M. Siméon was induced, from his previous knowledge, to expect good effects from the use of chlorine, and therefore introduced a considerable quantity into the mouth: the salivation in consequence ceased; the respiration became easy; the circulation less forced and rapid. The animal now raised its head, which before it could not do; put out its tongue, and scented the chlorine as if it took pleasure in respiring a salutary and agreeable atmosphere. In this manner, the symptoms gradually diminished, but as yet the cat could not stand up. Being exposed to the open air for a few minutes, it voided a large quantity of fæces, gradually rose on its feet, and made a few tottering steps: this was in one hour after the poisoning. At the end of two hours, traces of the event were scarcely visible; and the next morning the cat ate, drank, and walked, as if in perfect health,-no signs of the effect of the previous day remaining.-Ann. de Chimie, xl. 334.

2. Velocity of the Blood in Circulation, and Rapidity of Secretion.-Numerous experiments on these points have been made by M. Hering, Professor at Stutgard, upon horses, into whose jugular vein was inserted a solution of hydrocyanate of potash and iron. >>After some time, veins were opened in other parts of the body, and the blood taken out allowed to stand until a little clear serum could be removed from it; this being placed on white paper, a few drops of a solution of sulphate of iron added, and immediately after ca drop of strong muriatic acid: the hydrocyanate, if there, was immediately indicated by the blue colour. After being bled, the animals were killed, and traces of the introduced liquid sought for in the bsecretory organs and their products. bing

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The solution introduced into the jugular vein of the horse runs the course of the circulation, and arrives in the jugular vein of the opposite side in from 20" to 25", or from 25" to 30". It arrives in from 23" to 30" in the external thoracic vein of the oppo--site side; in 20′′ at the vena saphena major; in from 15′′ to 20′′ in the mesenteric artery; in from 20" to 26" in the maxillary artery; and in from 20" to 25", and from 25" to 30", in the metatarsal artery, always on the opposite side to the place of injection. The

velocity of the motion does not appear to be increased in the ratio of the pulsations of the heart; for in cases where the pulse was 60, 36 to 44, and 48 to 52, per minute, the results were the same. In one case the circulation was a few seconds slower.

The salt used was promptly secreted by the serous membranes, but only in small quantities, and that in the direct ratio of their distance from the heart. None was ever found in the cerebral cavities. The mucous membranes caused its secretion less quickly; but a few minutes sufficed to shew its presence at their free surfaces, and soon after at their other surfaces. The mucous membrane of the right half of the stomach secretes more promptly than that of the intestines, and the latter more rapidly than the surface of the lungs. The mucous surfaces, covered with an epithelium, (as the walls of the mouth, the pharynx, the left half of the stomach, in the horse,) gave no traces of the ferro-prussiate.

It was found but with difficulty in the liver, spleen, thyroid gland, &c., because of their dark colour. The salivary glands separated much of it. The kidneys, also, act powerfully upon it. It was found, after one minute, in the cortical and tubular parts, and in the pelvis. The small blood-vessels of the kidneys gave indications of it before the large ones, from whence it would appear either that the circulation is slower in the former, or that the salt commences its separation before hand.

The saline solution adheres in some cases to the sides of the bloodvessels, and is then easily discoverable, but more frequently it does not. The cause of the difference is not known. The shortest time which it takes to reach the thoracic duct is not known: a minute was sufficient in one case, and from two to five in others. It appears a little later in the lymphatic ganglia, from which it is supposed that a direct communication between the arteries and lymphatic vessels exists.

The foreign substance introduced is quickly ejected by the secretory organs, especially the kidneys. In from five to eight hours, traces of it had disappeared from the secretions, and in twenty-four hours, from even the solid and every other part. The ferro-prussiate of potash produces no inconvenience to the animal.-Zeitschrift für Physiol. ii. 85.

Girls.-The following Whilst considering the remark that, first, the

3. On the Proportion in Births of Boys to is extracted from a memoir by M. Poisson. births for six successive years, he was led to ratio of boys to girls was 19 instead of, as had been supposed; second, that the ratio being nearly the same for the south of France, and France entire, did not appear to depend upon climate, at least in that country; third, that, amongst illegitimate children, the ratio is less, and only

These results were published in 1823, and since then have been verified in a still greater number of births. The following is the

ratio of boys to girls, legitimate and illegitimate, in all France, for

The mean is from near ten millions of births, and differs only 1-200th from the extremes of 1817-1826: the mean of the thirty southern departments is 1.0665. The number of illegitimate children, in the above ten years, is nearly 700,000; and, in this number, the males are to the females in the ratio of 1.0484. The difference of 0.0172, between this and the great mean, is too large; and the number of births, from which it is drawn, too considerable to suppose it results from accident; and, however singular it may appear, there is great reason to believe that there is some cause existing, as to natural children, which diminishes the preponderance of male over female births. This influence is perceived even in the annual births.

The proportion between boys and girls is not the same for Paris as for the departments. From 1815 to 1827 there were born in Paris 215,000 legitimate children; the males were to the females in the ratio of 1.0408, or nearly 26, instead of 18. In the same time were born 122,000 illegitimate children, amongst whom the ratio was 1.0345, or about, instead of; from whence it is to be presumed that, in a great capital like Paris, there exists a particular cause which diminishes the preponderance of boys over girls, and acts both upon legitimate and illegitimate children.-Ann, de Chimie, xl. 39.

4. Inoculation of Hydrophobia.-Some experiments have recently been made at the Veterinary College at Alfort upon this subject. A horse, two dogs, and three sheep, were inoculated with the saliva of a sheep affected with hydrophobia, at various stages of the disease, but no symptom of the malady was produced on the animals thus experimented upon. Four months had elapsed after their inoculation when this report was made.-Med. Journal.

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5. Ossification of the Vitreous Humour.-M. Krehn has lately met with that rare case, the ossification of the vitreous humour of the eye. It occurred in a man seventy years old, who died of gastritis ; the preparation is placed in the Strasburgh Museum. The left eye was healthy, but the right presented the following appearance:The globe was diminished in size, had lost its spheroidal figure, and presented the appearance of four wrinkles, or furrows, corresponding with the insertion of the recti muscles. It was heavy and hard. When a horizontal section was made from behind forward, the sclerotic was found to be very thick, particularly at its posterior part, near the entrance of the optic nerve; the instrument was soon arrested

by a hard body, filling the whole space of the eye-ball behind the crystalline lens, and consequently occupying the place of the vitreous humour. Immediately within the sclerotic was the choroide membrane, distinct, and rather thicker than natural. The retina was unchanged the solid body within was marked by the same depression which had been observed externally. It was of a pale white colour, and was internally of a cellular texture, like the cancelli of the long bones. The crystalline was indurated, and of a yellowishwhite colour: the optic nerve was wasted.-La Clinique.

1.6. Vocal Sounds after Death.-M. Maingault states that, in expe riments made with the larynxian tube, he had occasion to observe a phenomenon noticed by M. Dutrochet, namely, that when air was forcibly thrown into the lungs of a dead infant or animal, the air, when thrown out again through the larynx, produced a sound analogous to that produced by the infant or animal in the living state.

7. Preservation of Blood.-Sugar refiners and others are often inconvenienced by the difficulty of obtaining blood at the time when it is required for use. M. Toursel has endeavoured in part to remove these difficulties, by proposing a method of preserving this agent for some time without injury. It consists in putting the blood into bottles, or other vessels, with very narrow mouths, and being careful to fill them up to the neck; a layer of oil, to the depth of at least half an inch, is then put upon it to cut off communication with the atmos phere, and the whole is left to itself. M. Toursel states that he has, in this manner, preserved blood, with all its physical and chemical qualities, from the 1st of December 1827, to January 1829.-Journ." de Commerce.

8. Stinging of a Gnat.-On the 25th of October last, and about two o'clock in the day, a gnat (culex pipiens) alighted on my fore finger. I held my hand still, and observed it. It immediately applied its proboscis to the skin, at the same time moving its antennæ and hind legs slowly up and down, which it continued to do for a few seconds, when it became apparently motionless, resting on its four front legs, with its hind ones stretched out in a line with its abdomen. I now felt a slight sensation where the proboscis was inserted,R but so faint, that, had not my attention been directed to it, I probably should not have noticed it, and this I only felt for a second or two. The abdomen now began to swell gradually; the influx of the blood" being clearly visible through its semitransparent skin; at the same time a clear watery fluid began to ooze from the anus, forming a round globule. It had a curious appearance to see blood flowing in at one end and water out at the other; the drop fell and another formed the abdomen all the time getting larger and larger, and redder and redder, until the second drop fell. The abdomen had now attained full three times its natural size, with a deep blood red hue, when, to my great vexation, the door opened, and away flew r

my