ON VARIOUS HYDROCARBONS PRO. BY M. E. SAINT-EVRE. By fractioning the products of the distillation C72 H 68 C56 H52 C52 H48 ..... .... .... 491 419 269.6 500 428 275 THE BEHAVIOR OF THE STRONTIA BY DR. SHERIDAN MUSPRATT, Professor of the Liverpool College of Chemistry, &c. "before the blowpipe baryta cannot be detected." Does he mean caustic baryta, or the salts of baryta? Caustic baryta imparts a yellowish color to the flame, but the nitrate of baryta gives a most decided greenish-yellow tinge to the whole flame. Numerous errors creep into volumes on chemistry, subsequent translators never taking the trouble to satisfy themselves as to the truth of certain statements. We find even in Turner's " Chemistry," that, "when sulphurous acid is added to a solution of selenious acid, pure selenium is thrown down." This is not the case. Selenious acid is not decomposed by sulphurous acid, unless the two are heated together. Further, Gerhardt stated, some years ago, and all the first chemists of France believed him, that valerianic acid could be abundantly obtained from indigo, by fusing it with potassa. At the request of my esteemed and honored friend, Baron Liebig, I repeated Gerhardt's lucrative process, and proved, analytically, the groundlessness of his assertion. His valerianic acid turned out to be a trace of acetic acid. IN several of the leading treatises on Chemistry, I observe the following: -Strontia salts impart a crimson color to flame." The students, in my laboratory, always precede the nascent testing, by an examination in the dry way, with the view of ascertaining the presence of those substances yielding characteristic colors to the flame, sublimates, or unmistakeable reductions, &c. When they received an insoluble salt of strontia, e. g. the sulphate, carbonate, or phosphate, they invariably mistook the base for calcia (lime) i.e. they obtained a yellowish-red flame, and a brilliant phosphorescence in the assay. I have lately performed several experiments, in order to collect satisfactory blowpipe reactions with regard to the salts of strontia. I find that only its moist soluble salts impart a fine carmine tinge to flame, an infallible proof of the presence of this earth. Sulphate of strontia, phosphate of strontia, and carbonate of strontia, dry or moist, do not tinge the apex of the flame. Chloride of strontium when dry does not impart the slightest carmine color to the flame of the blowpipe. When it is moistened, however, with a drop CHEMICAL EXAMINATION OF THE I may state, in conclusion, that too little attention has hitherto been paid to the blowpipe; but I am glad to find that it is daily becoming more and more appreciated, for its results are most certain and characteristic. It requires much practice in its use to be enabled to detect some of the metals; but a skilful blowpipist will often detect in a preliminary examination that which might escape him by the nascent method. "The blowpipe has, indeed, been to chemical analysis, all, and more, than the microscope has been to the observer who devotes himself to natural history." Chemists daily springing up should go over, diligently and carefully, old investigations in inorganic, organic, and blowpipe chemistry, instead of venturing into new fields of research. I am convinced that, by so doing, they will be amply rewarded. The chemist who removes one error from science, is as great a benefactor to science as the discoverer of a host of new compounds. of water, and then submitted to the point of the blowpipe flame, the intense crimson hue pervades the whole combustible, which disappears when the water has evaporated. Mr. Noad also states, with regard to baryta, that * Comptes Rendus, No. 13; Sept. 24, 1849. +Noad's Chemical Manipulation and Analysis." Before the blowpipe sulphate of strontia fuses to an opalescent mass, and colors the outer flame carmine red." FAT OILS EXTRACTED BY PRES. BY MR. S. DARBY. THE seeds of sinapis nigra and alba contain, as is known, a very considerable quantity of a colorless fat oil, whose chemical nature is almost unknown. J. Fontenelle * Annalen der Chemie und Pharmacie. obtained, by pressing mustard-seed, one-fifth of its weight of an amber-colored oil, of the density of 0.0202, solidifying below 32° F., soluble in four parts of ether, and in 1,000 parts of alcohol. According to Messrs. Henry and Garot, this oil contains a solid fat, crystallising in pearly bracteæ, fusible at 248° F., and not saponifiable. The experiments of Mr. Darby, on the composition of the fat oil of mustard, bring to light the existence of a new fatty acid, which must be ranked by the side of oleic acid. These two acids belong to the same series. The oil of white mustard which Mr. Darby used in his experiments was obtained by pressure from the seeds of eruca (sem. eruce), bruised, and gently heated. This oil is fluid, of an amber color, inodorous, and of a very sweet taste. It does not congeal during the most intense cold of winter; it merely becomes turbid and thick. When it is strongly heated in a tube, it disengages vapors of acroleïn, a proof that it contains glycerine. To extract erucic acid from it, this is the name given by the author to the abovementioned new acid, it is saponified with soda; the soap dissolved in water, and separated several times with chloride of sodium, is decomposed with dilute hydrochloric acid, and the mixture of fatty acid, washed with warm water, is converted into lead soap by digestion, on a sand-bath, with finely powdered oxide of lead. The plaster thus obtained is exhausted by ether, and the residue decomposed by hydrochloric acid furnishes a solid fatty acid, which may easily be purified by several crystallisations in alcohol: this is erucic acid. This acid crystallises, from its alcoholic solution, in brilliant needles; it fuses at 93° F. Its composition is represented by the formula C4 H42 04, which was confirmed by the analyses of the erucates of silver C44 H41 03, AgO, of baryta C44 H41 O3, BaO, and of lead C44 H41 O3, PbO. It is evident that this acid does not belong to the series of fat acids, containing an equal number of molecules of carbon and hydrogen, and whose general formula is represented by the symbol n(C2 H2) + O4. Like oleic acid, it contains less hydrogen than the corresponding term in the series of acids n(C2 H2)+O4. This term is for erucic acid, he benic acid of Völker C44 H44 04. The fat oil of black mustard, obtained by pressure from the seeds of sinapis nigra, yielded by saponification two fat acids, searic acid, erucic acid, and a liquid fat acid, of which the author does not know the composition. ON THE PROTEÏN COMPOUNDS. PROFESSOR MULDER has arrived at the following conclusions, after a prolonged investigation of proteïn 1. The albuminous substances hitherto examined may be regarded as a compound of C36 H25 N4 010, with sulphumid and phosphamid in different proportions. 2. Next to these are the compounds of oxy-proteïn C36 H25 N4 O, and C36 H52 N4 013. 3. Sulphur is not an essential constituent of the precipitate produced by acetic acid in a warm solution of albuminous substances in caustic potassa. Its quantity varies, and the form of the sulphur compound is S2 02. ON A COPPER AMALGAM.* BY DR. M. PETTENKOFER. IN Paris some dentists use an amalgam of copper with great advantage, to fill the cavities of carious teeth; it is sold in little cakes of about four grammes, costing two francs each. The color is grayish, it is very hard, and adheres so firmly together as to require a powerful stroke of a hammer to break it. It is of a finely granular crystalline texture. The sample I examined consisted of 30 parts of copper and 70 of mercury. When heated to the boiling point of mercury it swells a little, and a few drops of mercury appear on the surface. Being triturated for some time in a mortar and cooled, it is as soft as moist clay. In this state it can be pressed into the smallest cavities. After a few hours it becomes so hard that a sharp-edged piece will engrave upon tin and cut bone. When soft a very liquid amalgam of copper and mercury can be expressed by a powerful pressure between the fingers. The specific gravity in the soft and hard state differs little. This metallic compound is an interesting example of the effects of crystallisation and amorphiom on the properties of bodies. When soft it shows not a trace of crystallisation. It can be spread with a knife like plaster, but when hard it is very brittle; thin layers break like glass, and the fracture is granular crystalline. Among metals, this copper amalgam is the first known example of two states of a body at the same temperature; and is as instructive as the elastic amorphous sulphur and the brittle stick sulphur amongst the metalloids. It is a most valuable property for the purposes of the dentist, that the specific gravity should not * Annalen der Chemie und Pharmacie, June, 1849. vary in the transition from the amorphous into the crystalline state, as the mass when hard occupies exactly the same space as when soft. I have pressed the soft amalgam into glass tubes, and when cold it formed a perfectly air-tight stopper. : I have prepared amalgams containing between 25 and 33 per cent. of copper; all became crystalline after heating those containing most copper solidified more quickly, and became much harder than those containing less. Alloys of 25 parts copper and 75 mercury required three days to become completely crystalline. There is no atomic proportion between the copper and mercury in these crystalline compounds any more than between the constituents of other metallic alloys. A combination of 1 equivalent copper with 1 equivalent mercury would require in 100 parts 23.8 copper and 76.2 mercury. Perfectly analogous compounds occur in the native silver crystalline amalgams; by analysis their amount of silver varies between 25 and 86 per cent. Two metals crystallising together proves them to be isomorphous. This is the case with copper, silver, gold, and mercury. This copper amalgam is likewise an interesting example of the transference of the state of aggregation from one body to another; the liquid mercury, with the solid copper, passes into a firm crystalline state, which it can only assume at a very low temperature, if alone; as many solid salts be come liquid by contact with water. of sulphate of iron, with protonitrate of mercury, in a porcelain mortar, pouring on it boiling water and metallic mercury, and triturating it for some time. The at first brittle mass soon becomes soft, and when the right quantity of mercury has been incorporated, acquires the desired salve-like consistence.] ON A NEW METHOD OF DETER- BY PROFESSOR FORCHAMMER. THE test which he applies is hypermanganesiate of potassa or soda-which he prepares in this way. He heats the hydrate of potassa or soda with chlorate of potassa and the peroxide of manganese, according to the method of Wöhler. After heating, the salt is thrown into water, and so much diluted muriatic acid is added that it assumes a blueish-red color, upon which carbonic acid gas is let through, until the color becomes a bright red, and the manganesiate of potassa completely converted into hypermanganesiate. The liquid must be cleared, either by allowing it to deposit all the oxide of manganese, or by filtering through asbestos. This liquid may be kept for a very long time unaltered in a glass vessel, with a glass stopper. The next process is to ascertain the strength of the test, which is done by taking any determined measure of it, mixing it with water and a little alcohol, and then heating it. All the manganese is thrown down, and after being washed and exposed to a strong red heat, it is the compound oxide of manganese, 3 Mn + 40. This test is now applied in such a way that, for instance, one pound of the water that is to be tried is mixed with a small quantity of the test, and boiled. If the color have disappeared, another quantity is added, and the liquor again boiled, until in going on in that way, the red color of the liquid does not disappear any longer. After that, it is allowed to cool, and then the quantity of hypermanganesiate of potassa, which has not been decomposed for want of organic matter in the water, is determined by comparing its color with distilled water; to which have been added very small quantities of the test solution. If the quantity of the test which is thus added in excess be subtracted from This amalgam is useful to stop machines the whole quantity used, the real quantity and chemical apparatus, where cork, glass, of decomposed hypermanganesic acid is de&c., cannot be used; it will, probably, like-termined, and thus, also, the quantity of wise, be of service to artists and surgeons. Having tried several plans I found the following the best :-A weighed quantity of mercury is dissolved in boiling sulphuric acid, and the resulting crystalline paste of protoxide and peroxide of mercury, triturated with finely-divided metallic copper in a mortar with water, at 140° to 158° F., for some length of time. There must be sufficient copper, 1st, to reduce all the mercury; and, 2nd, that enough copper may amalgamate with the mercury. Copper obtained by reducing the oxide in hydrogen is the best, but that precipitated by iron from sulphate of copper will do. The plastic mass, well washed, is put into a leather bag, and as much mercury as possible is pressed out; it is then formed into little cakes, and in a few hours hardens to a mass, the fracture of which resembles in appearance the brittle alloy of lead and gold. [An editorial note states that this amalgam may be made with ease by moistening finelydivided copper, precipitated from a solution organic matter itself. This method is liable to one fault-viz., that the nature of the * British Association. organic matter may be different, and, accordingly, require different quantities of the test liquor to be decomposed. But the organic matter which generally occurs in water approximates almost always to humic acid, and thus the determination of the organic matter allows it to be compared. As to that part of the organic matter in water which contains nitrogen, the author thinks that he has found out a method for determining it by itself; but not having yet finished his experiments on that point, he must leave it out of the question. Water taken from a green sand-spring, about twelve miles from Copenhagen, contained so little organic matter, that one pound required only six measures of a test solution, of of which 100 measures contained the manganese of 0.526 of the double oxide of manganese; while water taken from a lake which communicates with a peat moss, required for 1lb., 74 measures of the same liquor. Professor Forchammer, in continuing for a whole year every week this analysis of the water which is used for supplying Copenhagen, observed the following facts:-1st. The quantity of organic matter is greatest in summer. 2nd. It disappears for the most part as soon as the water freezes. 3rd. Its quantity is diminished by rain. 4th. Its quantity is diminished if the water has to run a long way in open channels. ANALYSIS OF PLANTS BY INCINERATION.* BY M. CAILLAT. M. CAILLAT, Professor at the Agricultural Institute of Grignon, thinking that incinera tion, usually employed to obtain the organic matters of plants, yields incorrect results, and that a large proportion of the sulphur escapes among the gaseous products of combustion, has treated the residues of plants, such as lucern, &c., with dilute nitric acid, and succeeded in separating almost the whole of the mineral substances contained in them; a pulpy residue of 10 grammes, after washing and drying, having burnt readily, leaving only about 18 milligrammes of ashes, consisting of silica and a little peroxide of iron, both insoluble in the acid used. He has always thus obtained a larger proportion of mineral substances from plants than by incineration, and in some vegetables he found much more sulphuric acid than has hitherto been stated. Experiment proves that incineration decomposes a part of the sulphate of lime; this causes a loss of the sulphuric acid. Thus, on mixing a known quantity of sulphate of lime with starch and water, and incinerating the mass, the ashes did not contain as much sulphuric acid as the sulphate of lime. Mr. West asked if all organic substances Another experiment proves that sulphate were oxidised by the salt in question. Pro- of lime, converted into sulphuret of calcium fessor Forchammer replied, that nitrogenous by the influence of inorganic matter, is partly organic matters occasioned a precipitate by converted into carbonate of lime by the chloride of gold, which precipitate, on ana- oxygen of the air, which, burning at once lysing according to the ordinary method, the sulphur of the sulphuret and some cargave ammonia. But whether or not all the bon, forms sulphurous acid, which is evolved, nitrogen were thus thrown down he had not and carbonic acid, part of which remains comyet determined. Some further discussion bined with the lime, aiding thereby the disensued, in which Professor Faraday, Pro-placement of the sulphur. fessor Rogers, and Dr. Daubeny took part. While some of the Irish peat bears a strong resemblance in texture to that which we see in some rural districts of England, there is some which is nearly as dense and dry as coal, and will admit of polishing. This last kind is generally found deeper down, or under the other peat, and has, consequently, been subjected to its pressure for some considerable length of time. It will naturally be asked, why, when there is peat possessing the characters mentioned, and capable of being advantageously substituted for coal, the Irish markets are not supplied with it in preference to that turf peat which we ordinarily observe, which produces much less body of fire when used as fuel, is much more rapidly consumed, and leaves more earthy matter after its combustion. The fact is, the peat bogs of Ireland are at present under very bad management in every respect. The contract for the carriage of the peat to the Dublin market, which is by water, being made, as I am informed, by measure. ment, the carriers have no inducement to convey the denser kind, which would increase the weight of the load without producing any more profit to them than the same bulk of the lighter sort; added to this, the Irish peasantry, who are not gifted with much saving knowledge, find that the less dense turf ignites more readily, and as many of them have not the luxury of a stove, they cannot command sufficient draught to burn a dense fuel. If a proper separation of these two very different kinds of the same article were made, and if the carriers were encouraged to bring them both to the market, each would find a class of consumers, and much disappointment would be saved to those who desire to use peat as a substitute for coal in manufacturing operations. In a course of experiments instituted some months since, for the purpose of determining the uses to which the dense variety of the Irish peat could be applied, I subjected a portion to destructive distillation, and obtained as the principal products : 1st. A gas equal in every respect to oil gas, quite without the peculiar smell of that produced from coal, and free from any compounds of sulphur. 2nd. A carbonaceous residue, differing from both coke and charcoal, possessing some of the properties of each. In density, this form of carbon nearly resembles ordinary coke, while it differs from it in burning much more freely; indeed, a piece of it when ignited will frequently burn itself out. As regards the other products which peat yields by destructive distillation, although their collection might prove a source of profit, my observations lead me to the conclusion that they will not prove very important items. A portion of ammonia is formed, but the quantity is not so large as in the distillation of coal. From the foregoing observations, it is quite clear that the peat bogs of Ireland might be turned to very considerable account in that country; gas might be obtained from it for the illumination of the towns, and the coke, if properly prepared, would, I have no doubt, be found to answer for locomotives, and thus one great drawback to Irish railways, the expense of procuring coal from England, would be removed, while the gas would supply that which is at present a great deficiency to the small towns along the railway lines, and at a trifling cost. There is a variety of purposes to which carbonaceous matter, having the properties of that derived from the peat described, might be advantageously applied, such as some of the metallurgic operations, as a deoxidising agent, freedom from sulphur being essential, while the use of wood charcoal is impracticable from its expensiveness and bulk. It is much to be lamented that there is such a want of enterprise among that class of our Irish fellow-countrymen, which should be the employing class; to so great an extent is this the case, that I will venture to affirm that it would be next to impossible to induce any of them even to investigate this matter, for the purpose of ascertaining whether or not a sufficient supply of gas could be obtained from their own peat and coke for their locomotives, although the inquiry would cost but little; however, as this is a matter affecting the railway companies of Ireland, it is to be hoped that they will turn their attention to it. There are few who, if it should ever fall to their lot to examine the peat bogs of Ire,and! will not marvel why Ireland has been so long dependent upon England for fuel, and at the fact that manufactures have not been more cultivated to employ the great mass of laboring power possessed by that country, where the requisite fuel lies almost upon the surface, and, consequently requires but little capital for working; however, the time has arrived when public attention is being drawn to its capabilities, and the rest will, doubtless, follow. It is a shocking thing to see so fine a country-one whose noble mountains rear their heads so high, and inhabited by beings capable of drawing forth its latent treasures, and thus supplying their own wants, as well as those of their offspring, for want of a little directive energy and capital, so debased as to be a bye-word among nations, when nature has made it an ornament to the world. |