will give no quantitative result, as this salt does not prevent the volatilisation of the boracic acid from the aqueous solution. The only possible way of estimating quantitatively the boracic acid in an aqueous solution, is, in fact, by the addition of a weighed quantity of a fixed alkaline car sulphuric acids, the boracic acid being ex- On the 1st of November will be published, to be continued Monthly, THE DRAMATIC MAGAZINE, AND GENERAL THEATRICAL AND HUSICAL REVIEW; CONDUCTED AND EDITED BY THE PRINCIPAL DRAMATIC CRITICS OF THE DAY. Fach Part will be illustrated with Two beautiful Steel Engravings, from Daguerreotypes taken from Life, expressly for this Work, of the chief Dramatists, and of all the principal Actors and Actresses of the day, in their most celebrated characters, and in private costume. ied when centrated ethod is Gmelin, ulphuric ed with 1 of the BO com boracic acid does which is uoboride by means parated; esembles like that says that however, 1 a soluin pure its have, sible to as fluo succeed e boracic e added of lime id lastly e filtered btained, calcium. ite when Ham. Good my lord, will you see the players well bestowed? JOHN TALLIS AND COMPANY, 97 & 100, ST. JOHN ST., LONDON; & 40, JOHN ST., NEW YORK, Where all communications for the Editors must be sent, pre-paid I a base, d is emto effect osphoric of periting by of the Iowever, g added mixture of caris con ch conrbonate precipi or com nitric or solution. quently, ric acid. accurate way of separating boracic acid Strictly accurate results are not, however, from bases is by means of hydrofluoric and attained by it, as phosphate of baryta is not carbon is entirely consumed, no ash remaining behind. 0-3097 grms. of this substance, when kept for some time in a water bath at a temperature of 212° F., lost 0.0378 grms., corresponding to 12.2 per cent. of water, the amount found by Liebig in creatine prepared from different sources. I must tained th I have th very sm doubt as described berger, a conclude or less ar all the hi ON THI SOME do identity acids, ar maleïc a up the m the aci and of th compare (which i leic acid From he mad of their conclude tic and acid, wh ON BORACIC ACID AND ITS QUAN- BY PROFESSOR H. ROSE. THE various difficulties met with in the Shortly will be published, Part I., price One Shilling, Imperial 8vo, OF THE PLAYS OF SHAKSPERE, AS PRODUCED AT THE ROYAL PRINCESS'S THEATRE, LONDON from wl Daguerreo acid, alt tical wit types taken from Life, Principal Scenes and Characters in the various Plays, but also embodying faithful Likenesses and correct Costumes of our Principal Shakspe reians of In th Baup o attention example an orga trisacon only ve chemist assa of Duri M. Bau lisable cotton up to w flavequ expressly for only display ing the 1850-1. JOHN TALLIS AND CO., LONDON AND NEW YORK. Comptes Rendus, No. 11, Sept. 9, 1850. *Berlin Berichten, 1850. will give no quantitative result, as this salt does not prevent the volatilisation of the boracic acid from the aqueous solution. The only possible way of estimating quantitatively the boracic acid in an aqueous solution, is, in fact, by the addition of a weighed quantity of a fixed alkaline carbonate; this method is, however, rather tedious, requiring much time and attention. Carbonate of soda is preferable to carbonate of potassa, being more easily weighed accurately. It is weighed off in the fused state, and put to as much solution as is supposed to contain the same or half the amount of boracic acid, it is dissolved in the solution, and evaporated at a gentle heat. Carbonic acid is not expelled from the carbonated alkalis, by free boracic acid at the ordinary temperatures; and at a high temperature, or on evaporation only in a very slight degree; it is not until the whole has been evaporated to dryness, and the dry mass strongly heated, that any evolution of carbonic acid occurs, when great care is necessary. At a great heat, the mixture is liquid; at a lower temperature, only tenacious. If fused at as high a temperature as can be produced with a spirit lamp and a double draught, a certain weight is obtained on cooling, which will not vary even after long standing. But should the crucible be exposed to a moderate heat, after having been in a strong red heat, the weight strangely enough increases, and it is impossible to obtain, by this means, a certain weight. Whether the mass has been fused for a shorter or longer time, or whether the temperature employed has been higher or lower, the result will be the same. The carbonic acid in the fused mass is now estimated. If the amount of soda in the carbonate of soda used, and that of the carbonic acid which has escaped during the experiment, be subtracted from the weight of the fused mass, the quantity of boracic acid will be most accurately obtained. Although the same phenomena occur with carbonate of potassa, the results are somewhat less accurate, as this salt cannot be so accurately weighed off in the anhydrous state as carbonate of soda. It is, however, only rarely possible to employ this method of estimating the amount of boracic acid in aqueous solution, and only when no other substance, excepting perhaps ammonia, is contained in the solution, and that is expelled even without the action of carbonate of soda. It is well known that the best and most accurate way of separating boracic acid from bases is by means of hydrofluoric and sulphuric acids, the boracic acid being expelled as fluoride of boron, whilst the bases remain in the state of sulphates. Boracic acid may also be entirely converted into boracic ether by treating the borates with sulphuric acid and alcohol. This plan is, however, far less accurate than by using hydrofluoric acid, and should be tried when it is impossible to obtain concentrated hydrofluoric acid. When the method is employed, long ago proposed by L. Gmelin, of using hydrochloric instead of sulphuric acid, the boracic ether is produced with much less ease, the volatilisation of the boracic acid is slower and not so complete. No direct method of estimating boracic acid is as yet known, because this acid does not form with any base a compound which is entirely insoluble in water. The fluoboride of potassium is the only compound by means of which it could be completely separated; this salt is very sparingly soluble, resembles the silicofluoride of potassium, and like that is insoluble in alcohol; Berzelius says that it is somewhat soluble in it, which, however, is a mistake. It is more soluble in a solution of chloride of ammonium than in pure water. A great many experiments have, however, proved that it is impossible to estimate boracic acid quantitatively as fluoboride of potassium; it will not succeed even when the solution contains free boracic acid. If pure hydrofluoric acid be added to the solution, and then carbonate of lime to separate the excess of acid, and lastly acetate of potassa and alcohol to the filtered liquid, a fluoboride of potassium is obtained, which always contains fluoboride of calcium. But the results are far less accurate when the boracic acid is combined with a base, such as soda, and the above method is employed. Von Kobel has proposed to effect the separation of boracic from phosphoric acid by adding to the solution one of perchloride of iron, and then precipitating by an excess of lime; the addition of the solution of perchloride of iron is, however, unnecessary. Hydrochloric acid being added to the solution of a borate, and the mixture treated without heat with an excess of carbonate of baryta, no boracic acid is contained in the insoluble residue, which contains only carbonate of baryta. Carbonate of baryta, on the contrary, entirely precipitates phosphoric acid, whether free or combined, without heat, when some nitric or hydrochloric acid is added to the solution. Carbonate of baryta will, consequently, separate boracic acid from phosphoric acid. Strictly accurate results are not, however, attained by it, as phosphate of baryta is not ON THE NITROGENOUS PRINCIPLES BY DR. JOHN STENHOUSE, F.R.S. perfectly insoluble in a solution of borax. When phosphate of baryta is digested in a concentrated solution of borax without heat, the filtered solution after some time contains traces both of baryta and phosphoric acid, the latter being easily detected by molybdate IT is well known that several organic alkaof ammonia. Consequently, when a mix-loids, such as aniline, Picoline, Petinine ture of phosphate and borate, after the addition of hydrochloric acid, is treated with an excess of carbonate of baryta, without heat, and frequently stirred and filtered, the wash water leaves, after twenty-four hours, even after long edulcoration, a residue on evaporation, and molybdate of ammonia proves traces of phosphoric acid. But should the insoluble residue, after some washing, be dissolved by hydrochloric acid, the baryta removed by dilute sulphuric acid, the phosphoric acid precipitated as ammoniophosphate of magnesia, and the amount of phosphoric acid calculated from the calcined residue, a loss of phosphoric acid will be perceived, but it is inconsiderable; so that a result approximating closely to the truth will be attained by this process. When ammonio-phosphate of magnesia is digested, without heat, in a concentrated solution of borax, no phosphoric acid will be detected in the filtered solution. If a solution contains boracic and phosphoric acids, the latter may, therefore, be separated by precipitating it as ammonio-phosphate of magnesia, unless the solution likewise contains other substances, which will be precipitated on the addition of ammonia and a solution of magnesia. The precipitate will contain a slight trace of boracic acid. By this plan, a small excess of phosphoric acid is therefore obtained, similar to the loss occuring with the carbonate of baryta process. The difficulties which attend the estimation of fluorine with boracic acid have not as yet been surmounted. When the solution is acidified with nitric acid, an excess of carbonate of lime added, and the mixture heated and filtered, the whole amount of the fluoride of calcium corresponding to the fluorine in the solution is not obtained. Fluoborides have been formed, which are merely partially, and sometimes not at all, decomposed by the treatment with carbonate of lime. Fusion with an excess of carbonated alkali will completely separate boracic acid from bases in insoluble compounds; at least, by fusing borate of baryta and borate of magnesia with carbonate of soda, and treating the fused mass with water, the whole of the bases were procured quite free from all trace of horacic acid. &c., are obtained in the dry distillation of coal. Now, as coal is of vegetable origin, and these organic alkaloids all contain nitrogen, it is evident that they must be ultimately derived from the azotized principles contained in the plants from which the coal has been formed. Hence it appears pro bable that those proximate vegetable principles which are rich in nitrogen, such as vegetable albumen, fibrine, legumine, &c., will, when subjected to destructive distillation, yield these same alkaloids, or bodies closely resembling them, in larger quantities than the coal itself,-inasmuch as the powerful agencies to which that substance has been subjected during the course of its formation, must have destroyed a large amount of these azotized principles; and moreover, the great bulk of it is made up of non-azotized matter, the residue of woody fibre, &c., which can contribute nothing to the formation of the alkaloids. By considerations such as these, the author was induced to undertake the researches of which the following is an abstract. The A Since vegetable albumen, fibrine, and caseine, are very difficult to obtain in a state of purity, the experiments were made with those parts of plants, chiefly seeds, which contain those principles in the greatest abundance. The first experiment was made with the seeds of the common horsebean (Phaseolus communis,) which contain about 22 per cent. of azotized matter. beans were subjected to dry distillation in cast iron retorts, and the distilled products condensed by a Liebig's condenser. strongly alkaline liquid was obtained, containing, besides other products, acetone, wood-spirit, acetic acid, empyreumatic oils, tar, a very large quantity of ammonia, and several organic bases. The crude product was treated with a considerable excess of hydrochloric acid; the clear liquid decanted after the tar had settled to the bottom; the tarry residue treated several times with water containing hydrochloric acid; the several acid liquids mixed, and the whole boiled for a couple of hours. By this treatment, the acetone, wood-spirit, and a large proportion of the empyreumatic oils, were either driven off or separated by conversion into resinous matter. The acid liquid was then filtered through charcoal to separate the resins, and afterwards mixed with lime or soda and distilled. The distillate con- bly in their boiling-points, nevertheless retained a large quantity of ammonia, toge- semble each other very closely in their other ther with oily basis, the amount of the characters. They are colorless, transpalatter being greatest in the first portions rent oils, with strong refracting power, which passed over. The oily liquid was lighter than water, and having the peculiar separated from the ammoniacal solution by pungent, slightly aromatic odor which is means of a pipette; neutralized with hy- characteristic of this class of bodies. The drochloric acid, whereby the neutral oils odor remains on the hands and clothes for mixed with the organic bases were left un- a long time, and is strongest and most dissolved, and could be separated by filtra pungent in those bases which are most tion, and the solution supersaturated with volatile. They have a hot taste, not disacarbonate of soda, and distilled in a large greeable in a state of dilution, and resemretort. The oily bases again passed over, bling that of oil of peppermint. The bases together with a quantity of ammoniacal which distil over at low temperatures are liquid, from which they were separated by tolerably soluble in water, at any rate, the pipette. An additional quantity was more soluble than those whose boilingobtained from the weak alkaline liquid points are high. They all dissolve in every which passed over at the latter part of the proportion in alcohol and ether. They exfirst distillation, by neutralizing that liquid hibit strong alkaline reactions with turwith hydrochloric acid, concentrating by meric and reddened litmus-paper, emit evaporation, supersaturating with carbo- copious fumes with hydrochloric acid, and nate of soda, and again distilling. The neutralize acids perfectly, generally formoily bases obtained by these operationsing crystallizable salts. With the chlorides were again rectified with water to purify of gold, platinum, and mercury, they form them from the resinous matter which still remained; then repeatedly agitated with strong potash-solution, which dissolved out the remaining portions of ammonia, and formed a solution which could be separated from the oily liquid by means of a funnel; and lastly, dehydrated by repeated agitation during several days with fused hydrate of potassa, and subsequent distillation. The first two-thirds of the oily distillate were colorless; the remainder had a yellowish color, but was likwise rendered colorless by repeated rectification. The boiling-point varied considerably during the distillations, showing that the oily liquid obtained was a mixture of different bases. An attempt was therefore made to separate these bases by fractional distillation. The liquid began to boil at 108 C., at which point a small portion of a transparent, colorless oil passed over. The thermometer then rose quickly to 120°, and from thence to 130°, at each of which points small portions were collected. Between 150° and 155°, the boiling point remained stationary for a considerable time, and a considerable quantity of oil then distilled over; about the same quantity was collected between 160° and 165°. The boiling-points of the last portions varied between 165° and 220°. The products of these different distillations were again repeatedly rectified, and by this means bases were obtained corresponding more closely with those points at which the thermometer remained stationary during the first distillation. These bases, though differing considera double salts, soluble in water to nearly the same extent as the corresponding ammoniacal salts. They precipitate ferric and cupric salts, the precipitate in the latter case being easily soluble in excess, and yielding a deep blue solution. They do not alter by partial exposure to the air, but if exposed to a strong light, they turn yellow, especially those which boil at the higher temperatures. Nitric acid converts them into yellow resins, but without forming carbazotic acid. With hypochlorite of lime they form brownish resins, but give no trace of analine. When boiled for a few minutes in a retort, they gradually become colored, though the liquid which distilled over was colorless at first. At the close of the distillation, a small quantity of resinous matter remained in the retort. The quantity of these bases obtained was not sufficient to yield any very definite analytical results. It is not that the proportion of bases yielded by beans and other seeds is less than that obtained from animal substances; on the contrary, it is equal to that obtained from bones, and much greater than that yielded by coal: but we have not the advantage-as in the case of bones and coal-of being able to procure the crude oils in large quantity as the waste-products of manufacturing operations; and consequently the chemist is obliged to distil the seeds on purpose, an operation requiring very large apparatus and not conveniently conducted in the laboratory. The base which boiled between 150° and 155, was found by analysis to contain about 74-7 per cent. of carbon and 7.98 ✔ |