On the Retention of Organic Nitrogen by Charcoal. By E. C. C. STANFORD. Improvements in Chlorimetry. By JOHN SMYTH, Jun., A.M., M.I.C.E.I., F.M.S. The author showed that the use of the milky solution of bleaching-powder in chlorimetry is unsatisfactory, and was therefore glad to discover a method of securing a clear solution containing all the chlorine by dissolving the sample in an alkaline solution. This is conveniently done by adding, say, 10 grammes of bleachingpowder to 20 grammes of soda-crystals (Na, CO2+10H, O), filtering out the precipitated carbonate of lime, which is known to be washed when it no longer discharges the colour of dilute sulphate of indigo, and making up the filtrate by water to one litre of fluid. It is a clear colourless liquid of the sp. gr. 1.007, but if made of sp. gr. 1-233 it is slightly greenish, having a pleasant oily feeling between the fingers, contrasting favourably with the roughness of the decanted solution of the bleaching-powder, with which it gives a precipitate. Most satisfactory results are obtained from it by all the chlorimetrical methods; and it has the additional advantage of showing the amount of lime in the sample, a solution of known strength of carbonate of soda being added until a precipitate is no longer formed. It is manufactured and used in the north of Ireland for bleaching fine linens; and from the ease and accuracy with which the percentage of chlorine was obtained, the author was led to investigate the feasibility of converting bleaching-powder into it for chlorimetrical purposes, and obtained the above results. Contributions to the History of the Phosphorus Chlorides. I. On the Reduction of Phosphoryl Trichloride. The author has attempted, but without success, to prepare the phosphorus chlorides corresponding to the oxychlorides of vanadium discovered by Roscoe. He found that when phosphorus oxychloride was heated with metallic zinc in a sealed tube to a temperature above the boiling-point of mercury, the phosphorus trichloride (P C1,) was produced. It appears, therefore, that the action of zinc at a high temperature on phosphoryl trichloride is sensibly different from the action of this metal on the corresponding vanadium compound; in the former case the reaction is attended with abstraction of oxygen, in the latter with abstraction of chlorine. II. On the Preparation of Phosphorus Sulphochloride. The author found that perfectly pure phosphorus sulphochloride may be easily prepared by a reaction analogous to that by which phosphoryl trichloride has long been obtained; that is, by simply substituting P, S, for P, O, according to the following reaction, P, S,+3 PC1,=5 PS Cl2. The materials mixed in this proportion were heated in a sealed tube to about 150° C.; in a few minutes combination was quietly effected, and the entire contents of the tube were transformed into colourless phosphorus sulphochloride, a mobile liquid boiling constantly at 126° at 770 millims barom. Its vapour is extremely irritating, but when diluted with air it has an aromatic odour, reminding one of that of the raspberry. On the Dissociation of Molecules by Heat. By C. R. C. TICHBORNE, F.C.S., M.R.I.A. The term dissociation is applied by the author to specify a certain class of phenomena somewhat distinct from ordinary decomposition. This latter term is generally applied to any case of molecular change which has been consummated, whilst dissociation is used to convey a passive but present phenomenon. If this latter is carried far enough, it ultimately results in a rupture, and thus the phenomena of decomposition and dissociation are so intimately connected, that they can hardly be investigated alone. 1871. 6 Compound molecules exist in the solid, liquid, and gaseous condition, providing that the temperature necessary to convert them into these physical modifications is not above the temperature at which their components are dissociated. Thus we can easily conceive that a substance A may be of sufficient structural stability to pass through all the increasing vibratory action of heat without dissociation of its component molecules, until it has passed through the solid, liquid, and far into the vaporous condition; whilst a substance B has what the author calls a thermanalytic point, or the point where the equilibrium is broken. If it lies below 100 C., we have dissociation in the liquid condition among compounds so luble in water. A well-known natural group of bases had been studied as regards these phenomena, viz. the trioxides, alumina, chromic and ferric oxides, and it has been found that all the compound molecules of these bases were more or less dissociated on heating their solutions. The ferric compounds are the most easily affected. The solutions of these compounds, if pure, are almost colourless; the usual slight tinge being in most cases produced by the basic action of the water. By the cautious addition of dilute acid, almost colourless solutions will be procured. On the application of heat this solution becomes gradually darker and darker, until it becomes a dark reddish-brown fluid. If the water bears any considerable proportion to the salt, a basic precipitate falls before it has reached the boiling-point. The relative amount of the water is of the utmost importance in these phenomena, because its basic action lowers the thermanalytic point. The result of the dissociative influence of heat when a precipitate is not produced, is the repartitioning of the elements by which a basic and an acid salt are produced in the same fluid simultaneously. If these experiments are carried on under pressure, or in the presence of a great excess of water, the dissociative influence is so great from the increased range of temperature, that anhydrous oxide of iron can be produced in the presence of water. The compounds of chromium are capable of dissociation in a similar manner, and the change of colour produced by heat upon these solutions is due to basic condition, and not to the state of hydration of the salt as generally stated. The aluminic molecules obey exactly the same rule; but as the thermanalytic point is much higher, and as there is no chromatic change to mark the dissociative influence of heat, it is difficult to discern the phenomenon. Under the influence of solutions boiling at an increased pressure of 11 or 12 atmospheres alumina was procured. The same results may be obtained by increasing the basic condition of the solution by a large volume of water. As the pressure raises the boiling-point of the water until we reach the thermanalytic point of the molecule, so the basic action of the water upon the stylous group lowers the thermanalytic point until we get it within the range of 100° C. If 500,000 to 600,000 times the weight of water is used to the amount of salt, a precipitate is produced at 100° C. This precipitate is best seen by passing a beam of electric light through the flask. Most of the precipitates may be observed by the eye, but not all; they redissolve on cooling. On the behaviour of Supersaturated Saline Solutions when exposed to the open air. By CHARLES TOMLINSON, F.R.S. It is known that when a vessel containing a supersaturated saline solution is opened in a room, it immediately crystallizes provided the temperature be not too high. Mr. Tomlinson shows that supersaturated solutions of Glauber's salt (and also of Epsom salts and of alum) may be exposed to the open air of the country for many hours, and even be taken out of the flasks in clean metal spoons, without crystallizing. From a large number of experiments conducted under various conditions, the following conclusions are drawn: 1. That a highly supersaturated solution of sodic sulphate may be exposed to the open air of the country in an uncovered flask, and in cloudy weather, for from twelve to twenty hours, without any formation of the ordinary tenwatered crystals. 2. That if the temperature fall to 40° Fahr. and under, the modified sevenwatered salt is formed at the bottom of the solution just as in covered vessels. 3. That if the exposed solution suddenly crystallize into a compact mass of needles, a nucleus may always be found in the form of an insect, a speck of soot, a black point of carbon, &c. 4. That if during the exposure rain come on, the solution generally crystallizes suddenly in consequence of an active nucleus being brought down; but if the flask be put out during heavy rain, when we may suppose all the solid nuclei to be brought down, the rain-drops, now quite clean, fall into the solution without any nuclear action. 5. That the young and newly sprouted leaves of trees, such as those of the gooseberry and currant, have no nuclear action. 6. That in clear cloudless weather, when the force of evaporation is strong, the solutions by exposure produce fine groups of crystals of the ten-atom salt, just as a saturated solution would do if left to evaporate slowly in an open dish. 7. That if the solution, after being exposed to the open air, be brought into a room, it crystallizes immediately under the action of aërial nuclei. On the Constitution of Salts. By J. A. WANKLYN, F.C.S. Recent Progress in Chemistry in the United States. By C. GILBERT WHEELER. On the Oxidation products of the Essential Oil of Orange-peel, known as "Essence de Portugal." By C. R. A. WRIGHT, D.Sc., Lecturer on Chemistry in St. Mary's Hospital Medical School, and CHARLES H. PIESSE, Assistant Analyst in St. Thomas's Hospital. Through the kindness of Messrs. Piesse and Lubin, we have had the opportunity of examining a specimen of pure oil of orange-peel. As stated by Soubeiran and Capitaine, and also by Dr. Gladstone, this oil consists mainly of a hydrocarbon of formula C10 He, boiling at 174° C., and termed Hesperidene. We find that the crude oil commences to boil at 175°, and that 97.2 per cent. comes over below 179°; on redistillation over sodium this portion all comes over between 175° and 177° (uncorrected). The remaining 28 per cent. is a soft resin, which does not harden on standing, and is perfectly fluid at 100°. It is not volatile without decomposition, and after complete volatilization of residual hesperidene is inodorous; in alcohol, even boiling, it is but sparingly soluble, readily soluble in ether, and insoluble in water, to which, however, it communicates the aromatic bitter taste of orange-peel. It contains no nitrogen, and on combustion gives numbers agreeing with the formula C20 H30 Oq. Hesperidene redistilled over sodium is attacked with violence by concentrated warm nitric acid; by dilution of the acid with its own bulk of water the action becomes less violent; after boiling some hours with an inverted condenser attached, the evolution of red fumes and of CO, almost ceases. At this stage the hydrocarbon has principally formed a brown resinous substance, becoming a very thick viscid liquid at 100°, but setting on cooling to a hard brittle mass. This contains much nitrogen and less hydrogen in proportion to the carbon than the original substance. Its examination is not yet completed, but the numbers obtained are consistent with the supposition that it is derived from the original hydrocarbon by addition of oxygen and replacement of hydrogen by NO. With strong nitric acid this brown resin is further acted on, producing a yellow resin not softening at 100°, and containing nitrogen and less carbon and hydrogen than the brown resin. Much oxalic acid is also produced, and probably also another acid containing nitrogen; for the snow-white oxalic acid got by precipitation as lead-salt, decomposition with hydric sulphide, and several recrystallizations from water, contained much nitrogen, and yielded (as well as its silver salt) numbers not agreeing with but approximating to those required by theory. On heating one part of hesperidene with a mixture of three parts potassium dichromate, one of sulphuric acid, and thirty of water, an inverted condenser being attached, a slow evolution of CO, is noticed. After six or eight hours but little action has apparently taken place; but on distilling the product there is obtained, besides unaltered hesperidene, an acid liquid, which yields by neutralization a barium salt, giving all the qualitative reactions of acetate, and containing the calculated percentage of barium; a little formiate is possibly also produced, as the barium salt reduces silver nitrate slightly on boiling. The silver salt got by precipitation with strong silver nitrate and recrystallization from boiling water is pure acetate. The action of potassium chlorate and sulphuric acid on hesperidene is very energetic, a viscid tarry substance, not yet examined, being produced. The production of acetic acid from hesperidene renders a grouping of carbon atoms of the following nature probable :— CH, CH (C, H12)". We hope to be able to gain some further insight into the structure of the group C. II, and propose to submit to examination several other essential oils, hoping that the results may throw some light on the causes of the "physical isomerism of the turpentine group of hydrocarbons. On certain new Derivatives from Codeia. By C. R. A. WRIGHT, D.Sc., Lecturer on Chemistry in St. Mary's Hospital Medical School. When codeia is heated to 100° C. for two or three hours with from three to six parts of aqueous hydrobromic acid containing 48 per cent. HBr, there are formed, without appreciable evolution of methyl bromide, three new bases, of which the two last are produced by a further action on the first. These are The two first are soluble in ether, and may thus be separated (after precipitation by sodium carbonate) from the last, which is almost insoluble in this medium. By agitation of the etherial extract with hydrobromic acid there is obtained a viscid liquid, which contains little but bromocodide hydrobromate, if the digestion of the codeia have been carried on for a short time only, but contains also much deoxycodeia hydrobromate if the digestion have been continued somewhat longer. This latter salt separates in crystals from the viscid liquid on standing, the bromocodide hydrobromate furnishing a gummy mass only on standing and evaporation. By dissolving the portion insoluble in ether in dilute hydrobromic acid, and fractionally precipitating the coloured solution thus got with strong hydrobromie acid several times successively, bromotetracodeia hydrobromate is ultimately obtained in white amorphous flakes, that become tarry if warmed while moist, and colour more or less on drying. When once dry, a temperature of 100°C. does not soften the amorphous salt. The following reactions explain the productions of these three bases from codeia hydrobromate Codeia hydrobromate. 18 21 Codeia hydrobromate bromate. 18 bromate. 20 hydrobromate. 4(C,,H,,NO,,HBr)+C,,H,BrNO,,HBr=C1,H,,NO,,HBr+CH BN ̧0,2,4HBr. 21 21 83 By the further action of hydrobromic acid on each of the above bases methyl bromide is copiously evolved, and the following series of products formed :(A) From bromotetracodeia: bromotetramorphia, probably by the reaction— Bromotetramorphia. Bromotetracodeia. CH BrN, O12+4HBr 4CH, Br+Ces H, BrN, 012 72 83 12 = 75 (B) From bromocodide: probably at first a lower homologue bromomorphide (not yet isolated), converted subsequently into bromotetramorphia and deoxymorphia by the reaction. Bromomorphide. Deoxymorphia. Bromotetramorphia. 5C19 H73 BrNO, + 4H12O = 4HBr + C17 H19 NO2 + C88 H-5 BгN, Ô12. 78 2 17 19 2 68 (C) From deoxycodeia: only brackened tarry substances, not fit for analysis; hence probably the deoxymorphia got in B is not formed from deoxycodeia previously produced. Deoxymorphia and bromotetramorphia much resemble in all their properties their homologues deoxycodeia and bromotetracodeia; the first gives crystalline salts, the second amorphous ones. The constitutions of all the above have been verified by analyses of the hydrobromates, hydrochlorates, platinum salts, &c. In qualitative reactions, the deoxysalts are identical with apomorphia salts. On treating bromotetracodeia and bromotetramorphia with excess of cold strong hydrochloric acid, dissolving in water, and fractionally precipitating by strong hydrochloric acid, the bromine in these bases becomes replaced by chlorine, yielding the following bodies, that much resemble in all their properties the corresponding brominated salts: 72 83 129 Chlorotetracodeia hydrochlorate C2 H3 CIN, O12, 4HC1 By digesting codeia for six hours at 100° with hydrobromic acid, there was obtained a substance that gave numbers (after treatment with hydrochloric acid) intermediate between those required for the two last-named bodies. This may have been only a mixture of these two; but it seems very probable that a series of products should exist intermediate between these extremes, viz. Assuming that this substance was not a mixture, it might be termed chlorodicodeia-dimorphia. Dr. Michael Foster finds that the tetracodeia and tetramorphia compounds produce in adult cats a great excitement of the nervous system, and apparently paralyze the inhibitory fibres of the pneumogastric. Apparently the morphia compounds are somewhat more potent than the codeia bodies in this case. Deoxycodeia and deoxymorphia salts produce in adult cats convulsions more epileptic in character than tetanic. No trace of emetic symptoms has been observed with any of the salts of this class of bases, which in physiological effect, as well as chemical reactions, are almost indistinguishable the one from the other. This absence of emetic symptoms conclusively proves that apomorphia is not among the products of the action of hydrobromic acid on codeia. From its known production from this base by the action of hydrochloric acid, as well as from the analytical numbers obtained, the formation of apomorphia has been previously looked upon as probable. presence By the action of hydriodic acid containing 55 per cent. HI on codeia in of phosphorus, a series of substances have been formed that present the compositions included in one or other of the two general formulæ, 4X + nHI+ pH, O, |