isophthalic acid is the most satisfactory representative. | separated from the powder and crusts, and repeatedly reSalicylic acid thus became the 12 oxybenzoic acid, and the formulæ of a number of compounds were subsequently changed of necessity to place them in concordance with the results of the above reaction. But to take thus one experiment as the basis of a change as serious as that which ensued was looked upon by some chemists as insufficient; and indeed Meyer himself, in his first notice on this subject, says " Bei allen Schlüssen, die wir aus Reactionen, wie die oben beschriebene, ziehen, mahnt freilich die von Kekulé beobachtete Thatsache, dass die Phenolsulfasäure mit Leichtigkeit aus der Meta-Stellung in die Para-Stellung übergeht, zu grosser Vorsicht und ich werde daher auch die so eben aufgestellte Reihe nicht für völlig bewiesen halten, bevor ich nicht auch ein Glied der Meta-Rahe in gewöhnliche Phtalsäure werde übergeführt haben." Notwithstanding the fact that a great number of experiments were made with the object of more firmly establishing the principle adopted, by converting a member of the other series into the corresponding bibasic acid, they all failed; and the two analogous experiments of Meyer, viz., the conversion of sulphobenzoic acid into isophthalic acid, and the conversion of bromobenzoic acid into isophthalic acid, remained without support in their testimony. Attempts to apply the reaction to other fields were also unsuccessful, as shown in the experiments of Barth+ and Ascher. It is hardly strange, then, that with these circumstances the changes proposed by Meyer were not universally accepted; and those who opposed them on the ground that molecular re-arrangement might here play a role were certainly to some extent justified. As I was now in possession of the para-acid § corresponding to the meta-acid || with which Meyer performed his experiment, it became an interesting question as to what the conduct of this compound would be when fused with sodium formate. From the pure acid barium salt the potassium salt was prepared, and, the directions of Meyer being closely followed, this salt was fused with an equal weight of pure | sodium formate. In order to bring the mass to the point of fusion a comparatively high temperature was required. It then remained in a semi-liquid condition, apparently evolving gas for a short time, finally becoming much darker in colour—in fact nearly black. At a certain point volatile products, evidently containing sulphur, were given off, the odour of which was intensely disagreeable. The operation was performed in a silver crucible, and the mass constantly stirred with a silver spatula. Occasionally the vapours which were given off took fire above the crucible, and, on the gas-flame being now removed from beneath, and the flame of the vapour being extinguished, the mixture continued red-hot for a short time, presenting the appearance of a burning coal. When all had cooled down to the ordinary temperature, the crucible and contents were placed in water, and this boiled. The solution thus obtained was filtered, and, when cold, was treated with sulphuric acid. Thus was thrown down a very voluminous, flocculent precipitate, of a decidedly dark colour. In order to purify the product, it was filtered off, and well washed out with hot water; then dissolved in ammonia, and this solution boiled with animal charcoal. A nearly colourless solution resulted, and on treating this with sulphuric acid the precipitate formed was almost white. An attempt was made to prepare the barium salt by boiling with pure barium carbonate. After long-continued boiling with a large amount of water the acid had disappeared, and the salt was in solution. On evaporating gradually the salt was deposited in crusts during the process. It proved to be of exceedingly difficult solubility in water, boiling as well as cold. A small portion of it appeared to have a tendency to crystallise. This was *Berliner Berichte. iii. jahrgang, 112. ↑ Berliner Berichte, iv. jahrgang, 634. crystallised. It was also very difficultly soluble in water, and yielded an acid which resembled terephthalic acid in some properties. By means of various reactions, however, it was soon proved that this was not one of the phthalic acids, and it seemed probable that it might represent a variety of the thihydrobenzoic acids, the formation of which has been shown to take place in the reaction of Meyer for the preparation of isophthalic acid. The amount of the substance obtained was not sufficient to permit of its close examination, its perfect separation from the other substance formed being impossible. The difficulty of separation threatened at the outset to be a serious obstacle in the way of deciding the point under consideration. One method after another was tried, but the results were decidedly unsatisfactory, until finally the mixture was subjected to the influence of an oxidising agent (sulphuric acid and potassium bichromate). By this means the thihydrobenzoic acid (?) was so changed in character as to become soluble, whereas the other constituent of the mixture was left behind in a pure condition unacted upon. It was dissolved in ammonia, re-precipitated by means of a strong acid, filtered, and well washed out. In this condition it had the form of a very light, flocculent, white mass. It could be dissolved in boiling alcohol, and from this solution it was obtained in the form of microscopic needles which were deposited upon the sides of the vessel. This substance could not be brought to fusion. When heated in a capillary tube it sublimed from one part to the other before the flame, and was finally decomposed without fusing. It was almost absolutely insoluble in water, both boiling and cold; insoluble in ether. The pure substance could not be perfectly dissolved by boiling with barium carbonate. A small amount of the barium salt of the acid was, however, thus obtained, and this was very difficultly soluble in water, and did not crystallise. The calcium salt resembled this in every way. These are the properties of terephthalic acid, with the exception of the conduct toward alcohol. To this I am not inclined to attach much weight, as the acid which is described as insoluble in alcohol is that which is obtained by oxidation of xylene, and the condition of this acid differs essentially from that of the light mass obtained by precipitating it from one of its salts. Further, I found that after being dried, the acid, as obtained by me, was also insoluble in alcohol. I would hence rather consider this conduct as indicating a property of terephthalic acid which had been overlooked. The substance was proved to have the composition of terephthalic acid by the following analysis: 02325 grm. substance, dried over sulphuric acid, gave 04897 grm. CO2 =013355 grm. C and o'0832 grm. H2O=000924 grm. H. tassium parasulphobenzoate and sodium formate are fused The proofs that terephthalic acid is formed when potogether are thus conclusive. It remained, however, to show that neither phthalic nor isophthalic acid was formed at the same time. The crude product was boiled with the filtrate to cool, a small quantity of substance was dewater for a long time, and then filtered off. On allowing posited in the form of powder. The whole was shaken with ether, which dissolved the powder and extracted whatever might be in solution. The original solution from which the crude acid had been precipitated was also treated with ether. On uniting the ethereal solutions and distilling off the ether, a residue was obtained which dis * Ador, Berliner Berichte, iv. jahrgang, 622. solved readily in alkaline carbonates. It was neutralised CHEMICAL NOTICES FROM FOREIGN with barium carbonate. The barium salt was easily soluble and crystallised well. The free acid separated from this salt was easily soluble in hot water, and crystallised out on cooling. It had the fusing-point 120°, and all the other properties of benzoic acid. No other substance could be found. The quantity of benzoic acid obtained was very small in comparison to the whole quantity of the product, and its formation can easily be accounted for when we consider the character of the reaction. Here then, at least, no molecular re-arrangement takes place; and this, taken in connection with Meyer's experiment, certainly makes the case strong enough to command attention. The reaction is thus shown to be capable of application for the purpose of determining the constitution of compounds, and the changes proposed by Meyer can be demanded with greater confidence than before. The proofs that paraoxybenzoic and terephthalic acids belong to the same series had already been given by other reactions, though, acknowledging the described reaction, this would be the most direct proof of the fact. (To be continued). NOTICES OF BOOKS. * THIS small volume, as the author intimates in his preface, is intended for the use of medical students. It is undeniable that, if practising medical men are to fill the office of analysts under the "Public Health Act," they will certainly require a much more complete and practical knowledge of chemistry than they ordinarily possess at present. The work treats of gravimetric, volumetric, and colorimetric analysis, the examples taken being the determination of total solids in water and in milk, of caseine in milk of total solids, uric acid and albumen in urine, of chlorides in water, of hardness in water, urea in urine, of sugar and of cream. In colorimetric analysis we find examples of the estimation of ammonia, ureal and albumenoid, and of nitrates and nitrites in potable waters. In estimating the hardness of water, we observe that the a thor adheres to Clarke's original method, in preference to the modification introduced by Wilson. The directions for the determination of organic impurities in water are sound, being taken from Messrs. Wanklyn and Chapman, and there is no attempt to lead the student into the unwholesome mysteries of "previous sewage contamination." It would scarcely be possible to compress a greater amount of useful matter into the small compass of 57 pages. A Review of "Prof. Reese's Review" of the Wharton Trial. By Prof. W. E. A. AIKIN, M.D., LL.D. New York: D. Appleton and Co. A CRITIQUE on the evidence given, and on the theories put forward, to establish the innocence of the defendant in a poisoning case, with general remarks upon certain points of medical-or we might say chemical-jurisprudence. Those who remember the Tawell and the Palmer trials in England, or who have read Prof. Taylor's remarks on the lines of defence then adopted, will fully appreciate the attack which Prof. Reese-a witness, or rather scientific advocate, for the defendant Wharton-thought proper to make upon Dr. Aikin. * See V. Meyer, Ann. d. Chem. u. Pharm., clvi., 267. SOURCES. Under this heading will be found an encyclopædic list of chemical papers published abroad during the past week, with abstracts of all susceptible of advantageous abridgment. The two half-yearly volumes of the CHEMICAL NEWS, with their copious indices, will, therefore, be equivalent to an English edition of the "Jahresberichte." NOTE. All degrees of temperature are Centigrade, unless otherwise expressed. Berichte der Deutschen Chemischen Gesellschaft zu Berlin, April 28, 1873. Methods for the Analysis of Water.-F. Tiemann. The determination of hardness (magnesium) of sulphuric acid, nitrous and nitric acid, ammonia, sulphuretted hydrogen, and organic matter has led to constantly renewed discussion. Hence a re-examination of the methods recommended is desirable. Determination of Hardness.-The process for ascertaining the amount of alkaline earths in a water is always performed with a solution of soap, and depends on the double decomposition of the fatty alkaline salts in the soap, and of the lime and magnesia salts dissolved in the water. Insoluble lime and magnesia salts are separated out, and on shaking a froth is formed as soon as the decomposition is complete, and course of time three essentially different methods of a slight excess of soap is present in the liquid. In the determining the hardness by means of a soap solution have been made known; these are the old methods originally proposed by Clark, which has subsequently received several unessential modifications, the method of Boutron and Boudet, and that of Wilson. All three require that certain proportions of volume in respect of the quantity of water employed should be observed. It is in neither of these methods a matter of indifference whether other conditions remaining unchanged-the hardness is determined in 10, 50, or 100 c.c. of water. All three render the determination of hardness possible only within certain limits, and in case of a very hard water require its dilution with distilled water to a normal volume. Clark, and the chemists who have slightly modified his process, use as standard test a dilute solution of soap, and a normal volume which some fix at 100 and others at 50 c.c. of water. As the consumption of soap-liquor in this method does not increase in the same ratio as the amount of calcic and magnesian salts present a table becomes necessary, showing the amount of soap solution corresponding to different degrees of hardness. Such tables, adapted to various conditions of concentration, have been drawn up by Clark, by Faisst and Knauss. The cause of the unequal decomposition of the soapliquid may, perhaps, be found in the transient formation of soluble double compounds which at the outset of the process arise on the contact of soap and of the salts of the alkaline salts in very dilute solutions. In this manner the combination of an excess of the soap-liquid may be occasioned, and thus the latter may be deprived of the power of frothing when shaken. The alkaline salts (carbonates, sulphates, and chloride) formed in hard water on the decomposition of salts of alkaline earths by a larger amount of soap solution seem to diminish, and, finally, to hinder the formation of such double salts. The fact that highly concentrated neutral solutions of lime salts, mixed with soap, prevent it from frothing without giving an immediate precipitate (first pointed out by Maumené) agrees with this explanation. Boutron and Boudet avoid the above irregularities by applying a more concentrated solution of soap, and a normal volume of 40 c.c. of water. They use a peculiar measuring instrument (hydrotimeter) for reading off the concentrated test-liquid more easily. Its degrees do not correspond with the NEWS difficulty is rightly regarded as a flaw in all determinations of hardness by means of soap. It is not very prominent in the method of Clark, nor in that of Boutron and Boudet so long as the normal volume of water is duly diluted with distilled water, and as only small quantities of the soap-liquid are added at once. In Wilson's process it is rendered formidable by the addition of the soda solution. The foam disappears towards the end of the process so slowly that it is doubtful whether the addition of soapliquid should be continued or not. The hardness of a water rich in magnesian salts is, therefore, easily found too low by Wilson's method, as the following figures show. Three solutions were prepared, the artificial hardness of I. being 20°; of II., 65°; of III., 12°. The hardness of No. I. was caused by magnesia alone; that of II., 4'5° by lime and 2° by magnesia; that of III., 9° by lime and 3° by magnesia : cubic centimetres or its fractions. Wilson, who operates | salts still in solution from acting upon the soap. This under conditions closely resembling those of Clark, obtains regularity of decomposition by adding 4 c.c. of a saturated solution of soda to the normal volume of 100 c.c. of water. In using Clark's process the author adopted the modification of Faisst and Knauss. 45 c.c. of soap solution correspond to 12 milligrms. of lime in 100 c.c. of water. The soap solution for the method of Boutron and Boudet was so arranged that the amount filling 23° of the hydrotimeter exactly sufficed to produce the well-known permanent froth in 40 c.c. of water in which a neutral salt of lime, equivalent to 8.8 milligrms. carbonate of lime has been dissolved. After deducting 1o of soap solution for the formation of froth 22° are employed in decomposing the 8.8 of lime salt in 40 c.c. water. 100 c.c. of the same water contain 22 milligrms. of carbonate of lime. The transformation taken as regular shows 1° soap-liquid to I milligrm. carbonate of lime in 100 c.c. of water. If the degrees consumed are multiplied by o'56 we find the corresponding milligrm. of lime in 100 c.c. of water. The soap-liquid for Wilson's process was so arranged that 36 c.c. corresponded to 12 milligrms. lime in 100 c.c. of water which had been previously mixed with 4 c.c. solution of soda. In case of regular decomposition 3 c.c. solution of soap correspond to 1 milligrm. of lime in are 100 c.c. of water. The hardness of a number of natural waters was determined according to these three methods. Some of the results are given below. In these and the following experiments the degrees of hardness German, i.e., units of lime in 100,000; only in one case, which is specially pointed out, are French degrees employed, i.e., units of carbonate of lime in 100,000 parts of water : With sulphate of magnesia the results are less favourable. Soap solution acts unequally quickly upon the compounds of the different alkaline earths and those of magnesia. Neutral salts of baryta are more readily decomposed than those of lime, and the latter more readily than magnesian salts. Equivalent quantities of calcium and magnesium compounds require for their decomposition exactly equal quantities of the same soap solution; but its action upon magnesian salts is not only much slower, but, if we do not work with very dilute solutions, incrustations and films are formed which prevent the portion of the magnesian I. II. III. Clark. 19'75 6'45 11.88 B. and B. Wilson. 18.33 6.86 5'66 12'54 10.80 In case of Wilson's method the foam sometimes disreproduced by shaking. Hence it appears that the original appears after standing 15 to 20 minutes, and cannot be method of Clark is more accurate than either of the Determination of Magnesia.-The quantity of magnesian others, and is capable of the most general application. salt existing in solution in a water can be approximately estimated from the difference between the total hardness and the amount of lime as found by Mohr's process (titration with oxalic acid and permanganate), the number obtained being reduced to its equivalent in magnesia by multiplication by ths. The error occasioned by free carbonic acid-which also decomposes the soap solution-is neglected. In the author's experiments this amount was very trifling. The method of determining magnesia in a water by soap-liquid, after previous boiling and removal of the lime salts with oxalate of ammonia, cannot be pronounced trustworthy. It yields results which sometimes agree closely with those obtained gravimetrically, but on other occasions differs unaccountably. Contribution to our Knowledge of the Ashes of Vesuvius.-C. Osterland and P. Wagner.-The sample analysed contained : Traces of sulphur and sulphuric acid were also present. Formation of Phosphines under Co-Operation of Further Observations on the Phosphinic Acids.A. W. Hofmann. These four papers are reserved for extended insertion. On Propylen Diamin.-A. W. Hofmann.-The author prepares propylen diamin by acting with ammonia upon the bromide of propylen in sealed tubes, and afterwards, on the large scale, in an enamelled iron digester. Part of the liquid obtained was filtered from the deposit of bromide of ammonium, and digested with oxide of silver. A strongly alkaline liquid was obtained, in which, after the ammonia and alcohol had been expelled, chloride of platinum gave a pale yellow precipitate, perfectly in soluble in water. The rest of the liquid was treated with excess of solid potash, and heated in a retort to expel ammonia and alcohol. Propylen diamin was obtained as an oily liquid. After it had come over, less volatile bases made their appearance, secondary and tertiary diamines and triamines. Pure propylen diamin is a colourless, transparent, not very mobile liquid, boiling at 120° C. It consists of Carbon .. Hydrogen Nitrogen 48.64 NEWS upon monobrom-salicylaldehyde under the same conditions. It crystallises from alcohol in brick-red needles, and consists of C13H10BrNO. Anhydrous hydrocyanic acid reacted violently with a mixture of salicyl-aldehyde and aniline. The result was hydrocyanate of salicylanilide, in pure white crystals insoluble in water, but readily soluble in alcohol and ether. On exposure to the air, it becomes light red without decomposition; but if exposed to a continuous heat of 100° C. it is resolved into hydrocyanic acid and a resinoid residue. Its composition is C14H12N2O. Salicyl-paranitranilide is formed by the action of paranitraniline on salicyl-aldehyde. It forms pale yellow crystalline needles, which melt at 115° C. yielded a bright red substance fusing at 205° C., insoluble Certain Carbonic Acid Derivatives of Isobutyl.ether. The action of ammonia and hydrocyanic acid in water, and sparingly soluble in boiling alcohol and E. Mylius.-The compounds described are sulphoethyl-upon salicyl-aldehyde was also examined, the result being dioxy-carbonate of butyl, sulphobutyl-dioxy-carbonate of a red crystalline body of the composition C29H21N3O3. ethyl, trisulphocarbonate of butyl, and butyl-trisulphocarbonate of soda. 13'52 37.84 100'00 And its formula is C3HON2. Its affinity for water and An attempt to combine this body with hydrocyanic acid for carbonic acid is remarkable. Action of Chlorine upon Isobutyl Aldehyde.-G. A. Barbaglia.-The author attempted to prepare a monochlorated compound, analagous to Schroeder's monochloro-valeraldehyde, but obtained a substance having the composition C3H5CIO, and approaching more nearly to monochloraceton and epichlorhydrine. Transformation of Naphthylamine into Nitronaphthal.-G. Andreoni and R. Biedermann.-A preliminary notice. Naphthylamine is first converted into aceto-naphthylamine. From this mononitro-acetonaphthylamine is obtained, which, by the action of alkalies, becomes mononitro-naphthal. The Sulphacids of the Methylanilines.-G. A. Smyth. -The author has examined the behaviour of methylOils of Mustard.- Eugene Dell.-A preliminary aniline and dimethylaniline with sulphuric acid. The notice. Kresotenic Acid.-R. Biedermann and W. Pike. The material employed by the authors was cresol, in which sodium was dissolved under simultaneous introduction of a stream of carbonic acid gas. The pure acid obtained fuses at 174° C.; crystallises from hot water in fine shining needles, closely resembling salicylic acid. It takes a deep violet colour on contact with chloride of iron. Certain Derivatives of Cresol.-R. Biedermann.The author attempted to obtain substitution products with chlorine, and formed a monochloro-cresol, C-H,CIO, fusing at 56° and volatilising undecomposed at 240° C. This substance gives few reactions. It was not found possible to obtain from it orcin or any isomeric body by fusion with potassa or by boiling with alcoholic potassa. Cresol-sulphuric acid was prepared, and its potash-salt fused with potassa gave indications of proto-catechucic acid. The production of orcin was next attempted by means of iodides of cresol. Proper quantities of iodic acid and iodine were dissolved in dilute alkali, and the theoretical amount of cresol was added. A yellowishred body was ultimately obtained, which, with ammonia, took a red colour like orcin, and dissolved in fixed alkalies with a deep red colour. It did not yield the deep violet colour with perchloride of iron, and the results on analysis did not agree with orcin. New Members of the Stilben Group. - Julius Strakosch. This paper gives an account of the preparation and properties of dinitro-stilben, amido-nitro-stilben, and diamido-stilben. Contribution to the History of the Thio-amides. -R. Wanstrat.-The author has studied the action of iodine upon thio-cuminamide, amidothio-benzamide, and the action of nascent hydrogen upon the product resulting from the treatment of thio-cuminamide with iodine. Contributions to the History of the Derivatives of Salicylic Acid.-R. Wanstrat.-An account of the preparation and properties of salicylic acid-anilide, salicylic acid-nitranilide, and salicylic acid-toluidide. Derivatives of Salicyl-Aldehyde.-W. Haarmann. -Salicyl-aldehyde agrees with the remaining aldehydes in its behaviour with substituted ammonia. Salicyl-anilide, C13H1INO, has been previously obtained by Schischkoff, with separation of water on heating together equal volumes of aniline and salicyl-aldehyde. The author obtained monobrom-salicylanilide by acting with aniline monosulphacid of dimethylaniline is a crystalline substance of the composition C8H13NSO4. New Series of Diamines which Occur as ByProducts in the Manufacture of Methylaniline.-A. W. Hofmann and C. A. Martius. anilines.-A. W. Hofmann.-These two long and imThe Violet Colour-Derivatives of the Methyl portant papers are reserved for full insertion. Petersen.-A theoretical, not to say hypothetical, paper, graphic formula." consisting to a great extent of " Constitution of the Benzol Substances.-Theodore Aromatic Compounds Containing Silicium.-A. Ladenburg.-The author has formed and examined silicium-phenyl trichloride, ortho-silico-benzoic ether, and silico-benzoic acid, both anhydrous and hydrated. Derivatives of Cœrulignon.-C. Liebermann.—The author has previously described cœrulignon as a by-product obtained in the purification of wood vinegar, and belonging to the chinon class. He has now investigated the constitution of the substance, and has formed some of its derivatives and reactions. Constitution of the Allyl Compounds.-A. Kekulé and A. Rinne.-Allyl alcohol is readily attacked by dilute chromic acid. Even in the cold the odour of acrolein is observed, and carbonic acid escapes. If the liquid is distilled, after some time formic acid is detected in the distillate, but not acetic acid. If the same alcohol is treated with nitric acid, there is no odour of acrolein. Formic acid without acetic appears in the distillate, and there is much oxalic acid in the residue. The behaviour of the iodide and cyanide of allyl with chromic and nitric acids was also examined. On a Compound of the Cyanide of Allyl and Ethylic Alcohol.-A. Rinne.-The new compound consists of C4H5N,C2H6O. Its boiling-point is between 173° and 174°. A New Formation of Stilben.-Br. Radziszewski.— Phenyl-acetate of baryta with a slight excess of sulphur was submitted to dry distillation. The distillate contained a hydrocarbon, which, when purified and examined, proved to be stilben. The yield is abundant. On Graphite.-J. Stingl.-(See p. 264.) CHEMICAL NEWS, A. Geuther. A Hydrates of Monobasic Acids. controversial essay directed against Messrs. Grimaux and Henninger. The author considers that it is not his fault if his results, published three years ago, have not become known to these gentlemen. the corresponding nitriles. In this manner, pseudotoluidine is converted into orthotolúilic acid, and solid toluidine into paratoluilic acid. Brüning's New Method of Preparing Magenta.— Coupier. The author claims priority in the preparation of magenta, by treating aniline with nitro-benzol. A Question of Priority concerning some ThermoChemical Laws.-J. Thomsen.-The author considers that Berthelot and others are claiming and receiving the credit of having made certain generalisations which he himself announced several years previously. Affinity of Oxygen for Chlorine, Bromine, and Iodine.-J. Thomsen.-An examination of the amount of heat liberated during the formation of chloric, bromic, iodic, hypochlorous, and periodic acids. New Universal Support.-R. Muencke. - The construction and uses of this piece of apparatus could not be understood without the accompanying illustration. New Conversion of Oil of Turpentine into Cymol.A. Kekulé.-Iodine was added to the oil of turpentine-oil in small successive portions, the reaction being each time assisted towards the end of heat before a fresh quantity was added. In this manner 10 grms, of cymol were obtained from 50 grms. oil of turpentine and 22 grms, of Remarks on H. Fudakowsky's Paper "On Slow Oxidation as an Agent for rendering Oxygen Active."-Ed. Schaer.-The author confirms the facts cited by Fudakowski. He states that not alone insulation promotes the slow oxidation of the hydrocarbons and the simultaneous ozonisation of oxygen, but that heat, within certain limits, has the same influence. During a series of experiments performed in the year 1866, with the view of confirming Scheenbein's results on the antozone present in resins, he (Schaer) proved that on carefully distilling, in a place sheltered from direct light, a mixture of water with oil of turpentine, of juniper, of lemon, and other terebenes in a relatively large volume of air, both the distillate and the watery layer of the residual matter give unmistakeable indications of the presence of peroxide of hydrogen; whilst the oil, which has passed over, behaves as if it had been exposed for Bulletin de la Sociéte Chimique de Paris, tome xix., No. 10, some time to the action of oxygen under the influence of light. Schoenbein considers this behaviour of the essential oils with oxygen as a main support of his doctrine of the polarisation of oxygen. It may perhaps be assumed-without prejudicing the existence of antozone, so often asserted and so often denied that the differ entiation of oxygen occurs in all cases of slow combustion, that is, whenever air and water act upon organic or inorganic materials. Derivatives of Bromtoluol as Evidence con cerning the Nature of the Bromtoluols.-H. Huebner and P. Hässelbarth.-A table of the formulæ and properties of the parabromtoluol sulphuric, and parabromnitrotoluol sulphuric ẞ and a compounds. Oxidation Products of Colophonium.-Jos. Schreder. A preliminary notice. The author is examining the oxidation products of the so-called turpentine-resins, which, unlike the aromatic and the umbelliferous resins, are not attacked and decomposed by melting alkalies, but are oxidised by nitric acid forming acids not yet studied. Colophonium yields isophthalic and trimellitic acids. Monobasic Saccharate of Lime. R. Benedikt. The author has succeeded in preparing a salt, to which he assigns the formula C12H20, CaO11, and which contains10.80 Calcium.. Diphenyl-benzol.-G. Schultz.-When benzol is passed through incandescent tubes, we obtain along with diphenyl several bodies boiling at higher temperatures. Berthelot has isolated three of these, and distinguished them as— chrysen, benzerythren, and bitumen. The author considers that Berthelot's chrysen is diphenylbenzol, its analysis showing C18H14, whilst the formula of chrysen is C18H12. Synthesis of Aromatic Acids.-W. Weith.-The author recently made known that on treating phenylated oil of mustard with powdered copper, cyanphenyl is formed by the removal of sulphur, and passes into its isomer benzonitril. He has subsequently discovered that the above reaction is generally applicable, and that the isomeric tolyl mustard-oils are easily transformed into iodine. May 20, 1873. Binitro Compounds of the Higher Homologues of Benzol.-A. Rommier.-In his previous investigations, the author obtained from the oils of coal two xylenes, one of which was soluble in sulphuric acid of ordinary concentration, and the other insoluble. The soluble xylene the mixture of which melted at 61° C. These two bodies, yielded, with fuming nitric acid, two binitro compounds, re-crystallised from alcohol, have been investigated by Des Cloizeaux, who found that the less soluble binitroxylene, a, formed crystals belonging to the clino-rhombic system, whilst the more soluble binitro-xylene, ß, formed rhombic crystals of the triclinic system. On further examination it was, however, found that the salt ẞ, on repeated crystallisation, was transformed into a. The author concludes, therefore, that there is merely a single binitro compound corresponding to the xylene soluble in sulphuric acid. To sum up: by the action of ordinary sulphuric acid upon the oils of coal, we separate two xylenes, two cumenes, and two cymenes:-I. Hydrocarbides insoluble in sulphuric acid, accompanied by a certain quantity of formenic hydrides. (1). Xylene, boiling between 139° and 140°; its binitro compound melts at 92°, and forms clino-rhombic crystals. It differs from the binitro methyl-toluen of Fittig, which forms two kinds of crystals, the less soluble in long colourless needles, melting at 123.5°, the other in brilliant, transparent, monoclinic crystals, fusible at 93°. (2). Mesitylene, boiling at 165° to 167°, is the most abundant member of the series; its presence in coal oils was shown by Fittig, and its binitro compound examined by Des Cloizeaux. (3). Cymene, according to theory, should boil at 196°, the gradation of boiling-points between benzol and its homologues being 28° to 29°. Its direct verification did not succeed, from the presence of formenic hydrides boiling at adjacent temperatures. II. Hydrocarbides soluble in sulphuric acid and regenerated by distillation. (1). Isoxylene, boiling at 139° to 140°. Its binitro compound melts at 92° to 93°; very fragile prisms. (2). Pseudocumene, boiling at 165° to 167°, and forming two binitrocumenes fusible at 86°. (3). The cymene of this series is contaminated with naphthaline. On Aniline Black.-Ch. Lauth.-(See p. 275). Reply to the last Communication by M. Berthelot on the Mercurial Calorimeter.-P. A. Favre.-A continuation of the controversy between these two savants (see vol. xviii., p. 388). |