CHEMICAL SCIENCE.

RECENT CHEMICAL DISCOVERIES.

M. PASTEUR, of Paris, has availed himself of the beautiful discovery of M. Biot, of the influence of chemical composition in altering the rotation of polarized light, to show that the tartrates and paratartrates differ from each other only in the form of their crystals.

M. Ossian Henry has communicated to the Paris Academy of Sciences a memoir upon the existence of two new bodies belonging to the amide series, one a limpid yellowish oil, lighter than water, and disengaging a strong and penetrating odor, which he considers a bisulphuret of amidogen, the other a delicate yellow oil, which, when burnt, gives out an alliaceous smell, combined with a citron-like odor, which he regards as a sulphocyanuret of amidogen.

In the Brussels Academy, M. Louyet has given the results of some experiments on the passage of hydrogen gas through solid bodies, by which he shows that this subtile gas passes with facility through paper, and even through leaves of gold and silver. By directing a stream of the gas on one side of the leaf, it may be lighted on the othAs proving the extreme tenuity of the gas and the porosity of the metals, this is important.

er.

Anhydrous nitric acid, which has not hitherto been procured by chemists, has at length been prepared by M. Deville, of Besançon, France, by passing perfectly dry chlorine over equally dry nitrate of silver; no action takes place at ordinary temperatures, but the nitrate must be heated at first to 203° Fahr., and then lowered to 140° or 150°; the decomposition then proceeds quite regularly. At first hyponitrous acid is formed, but on lowering the temperature the new substance is deposited in crystals, in the cooled part of the apparatus; although a cold of 60 was employed to condense the vapors, the crystals were found to form when ice alone was used. The vapor of the anhydrous nitric acid penetrates caoutchouc tubes with such ease, that it is necessary that all parts of the apparatus through which it passes should be solidly joined. The anhydrous nitric acid forms large, brilliant, colorless crystals in six-sided prisms of the trimetric system.

The melting point is 85°, the boiling point 113°. With water much heat is evolved, and solution takes place without the escape of gas; the solution forms nitrates. Decomposition takes place so near the boiling point of the crystals, that the density of the vapor cannot well be determined. On attempting to recrystallize the substance in a sealed tube, in which it had been suffered to liquefy, a violent explosion took place.

LIQUID PROTOXIDE OF NITROGEN.

M. DUMAS has recently communicated to the Paris Academy of Sciences an account of the method used by him in effecting the liquefaction of large quantities of protoxide of nitrogen. He used a force-pump constructed for the purpose, securely bound with a belt of iron. He so arranged it that, the reservoir being surrounded by ice, the body of the pump was cooled by a circulation of water around it, and even the stem of the piston was always moistened by cold water. He then compressed into the reservoir in the course of two hours 200 litres* of gas, of which 20 suffice to produce a pressure of 30 atmospheres, about which liquefaction commences. The remainder of the gas furnishes a liquid. Once compressed, the liquid gas may be preserved in the reservoirs for a day or two, but if the stopcock is opened the gas escapes, and a portion freezes at first, but soon flows in a liquid state; the solid portion resembles a mass of snow. It melts upon the hand, and rapidly evaporates, leaving a severe burn. The liquid portion, which is far the most abundant, if received in a glass keeps for half an hour, even in the open air.

The protoxide of nitrogen is liquid, colorless, very mobile, and perfectly transparent. Metal dropped into it produces a hissing noise like that of red-hot iron plunged in water. Quicksilver causes the same noise, freezes, and affords a hard brittle mass resembling silver in color. Potassium floats upon the liquid and experiences no change, and the same is the case with charcoal, sulphur, phosphorus, and iodine. Ignited charcoal floats and burns with brilliancy. Sulphuric acid and concentrated nitric acid freeze. Water is converted to ice with a slight explosion.—Silliman's Journal, July.

AN ANCIENT ART REDISCOVERED.

AT a late meeting of the Asiatic Society of London, a human hand and a piece of beef preserved by means of a preparation of vegetable tar, found on the borders of the Red Sea in the vicinity of Mocha, were presented; a specimen of the tar accompanied them. Col. Hold, who presented the specimens, observes," During my residence on the Red Sea, a conversation with some Bedouin Arabs, in the vicinity of Mocha, led me to suspect that the principal ingredient used by the ancient Egyptians in the formation of mummies was nothing more than the vegetable tar of those countries, which is called by the Arabs Katren. My first trials to prove the truth of this conjecture

*Litre equals 0.220697 parts of British imperial gallon.

were on fowls and legs of mutton, and, though made in July, when the thermometer ranged at 94° in the shade, they succeeded so much to my satisfaction, that I forwarded some to England, and have now the pleasure to send to the Society a human hand prepared in a similar way four years since. The best informed among the Arabs think that large quantities of camphor, myrrh, aloes, and frankincense were used in the preparation of the mummies. These specimens will, however, prove that such additions were by no means necessary, as the tar applied alone penetrates and discolors the bone. This tar is obtained from the branches of a small tree or shrub, exposed to a considerable degree of heat, and it is found in most parts of Syria and Arabia Felix."

NEW METHOD OF PREPARING SULPHURIC ACID.

Ir has been generally supposed that the elements of sulphuric acid will not combine in a direct manner, and that the presence of water is necessary to insure its formation. Prof. Davy has lately shown that this is an error; and by the following experiment, made before the Royal Dublin Society, he demonstrated the practicability of forming sulphuric acid directly from its elements. Having placed in a dry Florence flask some sulphur, he vaporized it by the application of heat, and then ignited the vapor by means of a red-hot iron rod. The combustion extends throughout the vessel; at the instant of its taking place, both sulphuric acid and sulphurous acid are formed, the former descending in condensed drops, and the latter escaping from the flask. Prof. Davy hopes to render his process available in the manufacture of oil of vitriol.

CHLOROFORM.

Two French chemists have made a minute examination of chloroform and have communicated the results obtained to the Journal de Pharmacie et de Chimie, and it is from this that we derive the following statements. In commerce two liquids are known under the name of chloroform, which are of different origin, but are considered identical, and are often substituted for each other. There are, however, considerable differences in their properties; one, which may be called the normal chloroform, being derived from the reaction of hypochlorite of lime upon alcohol, while the other comes from the action of the same substance upon pyroxylic spirit, and differs very much from the first. That derived from pyroxylic spirit, which the authors conditionally call methylic chloroform, although it has the same appearance as the other, has a very different odor, being not sweet and agreeable, but nauseous, and having a burnt or empyreumatic smell. Its density is also less than that of the normal chloroform, and its boiling-point not so high, and its inhalation is far from pleasant, often causing general uneasiness, followed by heaviness of the head, continued nausea, and sometimes vomiting. On examination it was found that the two chloroforms are in reality identical, but that there is in the methylic variety a considerable quantity of foreign matter of an oily consistency, which is composed of several substances, and which it is

impossible at present wholly to expel. This oil is extremely hurtful to the animal economy, so that the normal chloroform is the only one proper for inhalation, and even this should be carefully rectified by distillation, as it often contains foreign substances, which produce the same effects as the methylic chloroform.

COMPARATIVE EFFECTS OF ANESTHETIC AGENTS.

DR. C. T. JACKSON, at the meeting of the Boston Natural History Society, April 4th, laid before the Society the results of his observation on the comparative effects of the inhalation of nitrous oxide, the vapor of chloroform, and sulphuric ether. Nitrous oxide, he said, administered in large doses, produces great excitement, which increases with the quantity inhaled. The vapor of chloroform, on the other hand, when inhaled rapidly, causes an immediate and entire prostration. The same is true, in a less degree, of sulphuric ether. They do not produce the intoxication which is caused by nitrous oxide, and this agent also, when administered slowly, fails to produce the usual effects. The vapor of chloroform, slowly inhaled, has an injurious influence, disorganizing the blood, and stopping the circulation in the capillaries. When suddenly introduced it retards, but does not stop, the circulation. Patients to whom it is slowly administered recover slowly, and it is important in all cases that enough air should be admitted with it. Persons inhaling nitrous oxide retain the sensibility to touch, and respiratory action is quickened, increases, and becomes deeper as the inhalation is prolonged. During the inhalation of chloroform and ether, on the contrary, the respiratory action diminishes. Under the influence of exhilarating-gas the system is made very irritable. Dr. Jackson thought that the few cases of excitement after the inhalation of ether might be attributed to the previous state of mind of the patient, or to alcohol combined with it. Conclusions drawn from experiments upon animals with these agents, should be received with great caution, for their action on animals differs according as these have or have not a cutaneous perspiration. It kills those of the latter class. Dr. Jackson recommended a mixture of chloroform with alcohol, in the proportion of an eighth or a quarter of an ounce of the former to four ounces of the latter.

Dr. Warren remarked, that from his own experience he preferred ether to chloroform, as being much safer, and in his own practice used chloric ether in preference to either of the other anaesthetic agents.

USE OF ANESTHETIC AGENTS DURING SURGICAL OPERATIONS.

STANISLAS JULIEN has found, in examining the Chinese books in the National Library at Paris, the proof that the Chinese have been long acquainted with the use of anesthetic agents during surgical operations. The extract which he gives is from a book published about the commencement of the sixteenth century, in fifty volumes quarto,

and entitled, "Kou-kin-i-tong,”-General Account of Ancient and Modern Medicine,--and refers to the practice of a celebrated physician, Ho-a-tho, who flourished between the years 220 and 230 of our era. It states, that, when about to perform certain painful operations, "he gave the patient a preparation of hemp," (Hachich), and that at the end of a few moments "he became as insensible as if he had been drunk or deprived of life." After a certain number of days the patient was cured, without having experienced the slightest pain during the operation. In a subsequent notice he also shows that the same physicians use the hydropathic system as a cure for certain diseases; among others, chronic rheumatism.-Comptes Rendus, Jan. 29.

NAPHTHA VS. CHLOROFORM.

PROFESSOR SIMPSON has been testing the properties of naphtha, which seems to be as good as ether for inducing temporary insensibility. Professor S. administered the naphtha to two patients, a man and a boy, on whom Mr. Milter performed the painful operation of extracting portions of necrosed bones from the tibia, by perforating the newly-formed shell with the trephine, and removing the sequestra with the forceps. The sleep induced was deep and tranquil, and the breathing was less stertorous than when chloroform is employed; but it was remarked, that the effect of the naphtha upon the heart's action was much greater, the pulse becoming extremely rapid and fluttering, thus rendering it less safe as an anesthetic agent than chlo

roform.

INHALATION OF HYDROGEN GAS.

M. VAN ALSTEN, of Rotterdam, has recently fallen a victim to his devotion to science. He was the author of a work on chemistry, and was desirous before finishing it of testing to what degree a man might without danger inhale hydrogen gas. He tried the experiment on his own person, and, in spite of all the exertions of his physicians, he died in a few hours.-Athena um, June.

NEW METHOD FOR THE EXTRACTION OF SUGAR FROM SUGAR

CANE AND BEETS.

THE most extraordinary and valuable discovery which has been made during the year 1849 is undoubtedly that of M. Melsens, Professor of the State Veterinary and Agricultural College of Belgium, relative to the extraction and clarification of cane or beet sugar. The success which has attended this gentleman's experiments has caused the greatest sensation among the manufacturers and statesmen of France and Belgium. This could not be otherwise in countries where so large a capital is invested in the growth of beets, and the manufacture of sugar from them, in the refining of exotic sugar, and the important collateral interests to which they have given rise. A committee of the most distinguished scientific men of France and