posing organic matter, leaves, &c., which in the processes of agriculture and by the influence of the earth-worm, &c., become embedded in the soil. M. Corenwinder, however, does not say what becomes of this carbonic acid. Liebig and other chemists answer the question better in showing that the carbonic acid is taken up by water which percolates through the soil, and that it is then used in eroding rocks and dissolving up otherwise insoluble mineral matters.

Aeriferous Vesicles of the Utricularia.-S. B. Schnetzler publishes an account in the Annals of Natural History,' of these curious appendages to the leaves. The genus Utricularia consists of aquatic plants which are found in the stagnant waters of ditches, marshes, &c. The leaves are submerged and divided into fine lacinæ furnished with the remarkable utricles. De Candolle states that when the plant is young these vesicles are filled with a mucilage which is heavier than water, and the plant held down by this ballast remains at the bottom. Towards the period of flowering, the leaves secrete a gas which makes its way into the utricles and drives out the mucilage by raising an operculum or lid with which the utricles are furnished. The plant thus becomes furnished with a multitude of air-bladders, and rises slowly and at last floats at the surface. After flowering in the air, the mucilage is again secreted and the plant sinks again to ripen its seeds below water. M. Schnetzler has carefully investigated the morphology and history of these organs, and concludes that they play the part at once of organs of respiration and of a hydrostatic apparatus. The organs do not appear at a given moment and for a particular purpose, but as a natural consequence of the anatomical structure of the plant and the action of the surrounding medium. After some philosophical generalizations the author observes, "The totality of the forms in which life manifests itself upon the earth, during a given epoch, appears to us like a magnificent mosaic, of which the different pieces brought together mutually determine their nature."

The Fall of Leaves.-Dr. Maxwell Masters has recently discussed this subject in a very seasonable article in the Popular Science Review.' It appears from the researches of M. Trécul (published in the Comptes Rendus') and others, that in many plants a phenomenon occurs just before the fall of the leaf, which is not unlike the process which accompanies the shedding of horns in animals. It consists in the obstruction of the proper vessels at the base of the petiole or leaf-stalk. This obstruction is caused by the multiplication of cells, which first occurs in the parietes of the vessels. The cells increase and multiply, till at last the vessels are completely choked up in the neighbourhood of the insertion of the leaf, and thus a differentiated plane is formed, across which the leafstalk breaks, and the leaf accordingly falls.

Movements of the Sensitive Plant.-M. Bert and M. de Blon

deau have published accounts of some investigations into this highly interesting matter in the Comptes Rendus.' It is to be regretted that more critical examinations of the phenomena of movement in the higher plants have not been made. M. Bert shows that the

natural and regular movement of the leaves, which takes place in the Sensitive plant, is produced by a different cause from that to which the sudden contraction is due when the plant is touched by the fingers. M. Blondeau's observations are exceedingly curious, and are well worth further examination. He submitted three plants to the influence of an electric current from a Ruhmkorff's coil. The first he acted on for five minutes; when left to itself, the plant seemed prostrated, but after a quarter-of-an-hour, the leaves opened, and it seemed to recover itself. The second specimen was acted on for ten minutes. The specimen was prostrate for an hour, after which it slowly recovered. The third specimen was galvanized for twenty-five minutes, but it never recovered, and in twenty-four hours it had the appearance of a plant struck by lightning. A fourth plant was etherized and then exposed to the current. Strange to say, the latter had not any effect, the leaves remained straight and open; thus proving, says M. Blondeau, that the mode of the contraction of the leaves of the Sensitive plant is in some way allied to the muscular contraction of animals.

5. CHEMISTRY.

(Including the Proceedings of the Chemical Society.)

AMONG the papers calling for special mention this quarter are those by Dr. A. W. Hofmann, "On the Production of Formic Aldehyde." The method by which the author has succeeded in forming this hitherto unknown body was shown at a meeting of the Chemical Society, and will be described in our Report of the Proceedings. Other papers of great scientific value have been communicated by the same author to the Royal Society, "On the Homologues of Prussic Acid."* These also were briefly referred to at the meeting of the Chemical Society.

Dr. E. Schunck has also contributed to the Royal Society a valuable series of papers "On the Chemistry of Urine." These, as well as the paper by Dr. Hofmann, do not admit of abridgment, and we must refer our readers interested in the subjects to the Proceedings of the Royal Society.†

The past quarter has not been marked by any specially interesting discovery, and but few facts call for notice. M. E. Duclaux+

*Proceedings of the Royal Society,' vol. xvi., p. 144. Comptes Rendus,' t. lxv., p. 1099.

+ Vol. xvi., p. 73.

has noticed the formation of what he believes to be a Hydrate of Sulphide of Carbon. If a little water is placed on a glass plate, and a watch-glass full of the bisulphide is set in the midst and then blown upon, the water soon congeals, and the watch-glass is filled with snow-white flakes of the supposed hydrate. A lighted coal brought to the snowy mass sets fire to the bisulphide, which burns away, leaving the water with which it had united. The author has several times determined the amount of the water, and finds it to be constant, and just the quantity required by the formula 2 C S, H, O.

The formation of this substance, we may add, is easily shown in another way. If a stream of the bisulphide is made to trickle down a piece of loose twine, the twine quickly becomes covered with a thick crust resembling hoar-frost. The substance, whatever it may be, rapidly evaporates, leaving the twine perfectly dry.

A new process for the production of sulphuric acid has been patented in France, and probably in England, by MM. Tardani and De Susini. Its great recommendation is that it dispenses with the large leaden chambers necessary to the English process. We must refer our readers to the source indicated below* for full particulars, and need only say that the Sulphur or Pyrites is burned in compressed air, and the sulphurous acid is first washed to free it from arsenic and other contaminations, and is then brought in contact with the nitric vapours in a small leaden chamber of peculiar construction. The reactions are precisely the same as in the old mode: the apparatus, however, it is said, occupies forty times less space, and an acid is obtained free from the ordinary impurities.

A new process for the manufacture of Soda has also been patented in France by M. Kessler. As in Leblanc's process, the inventor starts with common salt. This is intimately mixed with sesquioxide of chromium, either alone or with peroxide of manganese, and then roasted in a current of steam. The result is the evolution of hydrochloric acid, and the formation of chromate of soda. When the evolution of hydrochloric acid has ceased, the charge is drawn from the furnace, mixed with a proportion of charcoal or coal, and then reburnt. In this way the chromate of soda is converted into carbonate with the reproduction of sesquioxide of chromium. The soda is separated by lixiviation, and the sesquioxide is reserved for a future operation.

Two other technical processes deserve a short notice. One is for the extraction of indigo from rags dyed with that substance. The rags are first saturated with a weak solution of caustic soda, then placed in a boiler with a double bottom, and exposed for some hours to steam at 45lbs. pressure. The indigo in the rags is

*Bulletin de la Société Chimique de Paris,' Oct., 1867, p. 295.

reduced, and may be washed out. It may afterwards be precipitated from the soda solution, and recovered in a state equal to the best commercial sort.

Another inventor proposes to shorten the time of dyeing Turkey-red, by a previous oxidation of the oil used. This M. Bernard effects by heating the oil to 95° C. with a solution of chlorate of potash, and adding very gradually oxalic acid. The mixture is afterwards boiled for some hours. The oxidized oil, it is said, may be employed alone or in the form of an emulsion.

In connection with technical chemistry, we may mention the publication of a valuable paper "On the Cumberland Hæmatite Ores," by Dr. E. J. Tosh.*

A very delicate test for hyposulphite of soda has been published by Mr. Carey Lea.† A very dilute, but rather strongly acid, solution of sesquichloride of Ruthenium is first rendered alkaline by ammonia, and then boiled with the suspected solution. If hyposulphite be present, the liquid assumes a red colour, which varies in intensity according to the amount of hyposulphite. A solution containing one four-thousandth gives a clear rose-red; one containing a twelve-thousandth, a well-marked pink colour. A strong solution gives a colour so intense as to appear almost black. Such a test will be highly appreciated by photographers; but, unfortunately, ruthenium is yet a very rare metal.

PROCEEDINGS OF THE CHEMICAL SOCIETY.

The first meeting of the present season was held on November 7. After the adoption of an address of condolence to Mrs. Faraday, Mr. W. H. Perkin read a paper "On the Action of Acetic Anhydride upon the Hydrides of Salicyl, Ethly-Salicyl, &c." A paper by Messrs. Chapman and Smith, "On Nitrous and Nitric Ethers,' was next read. It gave an account of the methods adopted by the authors for preparing the nitrates and nitrites of methyl, ethyl, and amyl, and described the reactions and decompositions which these bodies undergo when treated in a digestion apparatus with metals, acids, and other re-agents. The most interesting part of the communications was the description of an easy mode of preparing nitrate of amyl in large quantities. Three measures of a mixture of one part of nitric and two sulphuric acid are placed in a beaker set in a freezing mixture, and to these is added very slowly one measure of amylic alcohol. The addition is best made with the aid of a dropping funnel, the stem of which, reaching nearly to the bottom of the mixture of acids, serves as a stirrer. The nitrate of amyl is

*Chemical News,' Oct. 18-25, 1867.

† 'Silliman's Journal,' Sept. 1867; and Chemical News,' Oct. 25.

produced without apparent action, and forms an oily layer on the surface of the acids. This is separated, washed with warm water, and rectified over chloride of calcium. The nitrate of amyl thus obtained is a colourless liquid, which boils at 147°-148° C., and at 7° or 8° C. has the same density as water. The inhalation of its vapour produces severe headache and other distressing symptoms.

Mr. Robert Warington then gave a short account of a long series of experiments, undertaken to determine the part taken by Oxide of Iron and Alumina in the Absorptive Action of Soils. The results may be summed up in a few words. Ferric oxide and alumina were found to withdraw nearly all the phosphoric acid from a carbonic aqueous solution of tricalcic phosphate. Hence the author believes that all the phosphoric acid applied to land in the shape of manure must ultimately become converted into phosphates of these bases; and, if sufficient iron is present, by preference into phosphate of iron. The absorptive action of the soil is thus seen to be dependent upon chemical affinity, and not upon physical attraction. As regards potassium and corresponding ammonium salts, it was found that the absorption was much greater in the cases of the phosphates, sulphates, and carbonates than with the chlorides and nitrates.

A discussion followed, in which Professor Way and Drs. Voelcker and Gilbert joined. The accuracy of Mr. Warington's results was not contested; but it seemed to be a general opinion that laboratory experiments of the kind described threw but little light on what happens in soils as they exist. Dr. Voelcker remarked that there was a remarkable tendency in nature for the soil to take care of itself; and if there should happen to be a deficiency of any one ingredient, it was quickly remedied by prior selection from a mixture of materials presented in the shape of manure. Dr. Gilbert agreed in believing that soils have almost an instinct to guide them as to what they should do.

The next communication was "An Analysis of the Water of the Holy Well, a Medicinal Spring at Humphrey Head, North Lancashire," by Mr. T. E. Thorpe. The water in question contains 508-5 grains of salts in a gallon, of which 331-75 grains is chloride of sodium, 88-49 grains calcium sulphate, 9.17 potassium sulphate, 24.39 grains sodium sulphate, and 43:48 grains magnesium chloride. The other ingredients need not be quoted.

An abstract of a paper by Dr. Wanklyn and Mr. A. Gamgee was next read. It was "On the Action of Permanganate of Potash on Urea, Ammonia, and Acetamide in strongly Alkaline Solutions." From the results obtained by the authors, it would seem that when artificial urea is heated in a pressure tube with a liberal amount of potash and permanganate, little or no oxidation takes place, and