characteristics of acetic acid. It was converted into a barytasalt, and the per centage of barium determined. '6306 grm. gave 5738 Ba2SO4 or 53.5 per cent. Ba 53.7. These numbers can leave no doubt that the substance in hand is acetic acid. A portion of the distillate which was supposed to contain aldehyde was heated in a sealed tube with a fresh portion of bichromate of potash and dilute sulphuric acid whereby it also was converted into acetic acid. No ammonia could be detected in the mixture of chromate and sulphuric acid, even though examined before the violent final reaction. The method of examination adopted consisted in rendering a portion of the fluid from the retort, alkaline with potash, and then distilling into water; the solution so obtained was then neutralized with sulphuric acid and evaporated almost to dryness, and strong alcohol was added; this dissolves the sulphate of ethylamine, but not the sulphate of ammonia. This method of examination would not discover very small traces of ammonia, but would have detected any considerable quantity. From the above it appears, therefore, that ethylamine yields by oxidation nitrogen, water, acetic acid and aldehyde. 3. Action of Acids on Naphthylamine. (Preliminary Notice.) By ERNEST T. CHAPMAN. IN a former paper, I mentioned several methods by which azodinaphthyldiamine may be produced.* These were; First. Action of nascent hydrogen on dinitronaphthylin. (This method, however, I could not succeed in verifying.) Second. Action of one equivalent of nitrous acid on two equivalents of naphthylamine. Both this and the preceding method were announced by Messrs. Perkin and Church. Third. Action of nascent hydrogen on a mixture of nitroand dinitronaphthalene. Fourth. Action of zinc-ethyl on a similar mixture. Fifth. Action of ammonia on a strongly acid solution containing naphthylamine and nitrous acid; it is to be remembered VOL. XIX. *Chem. Soc. J. [2], iv, 135. 2 A that potash cannot be substituted for ammonia in this preparation. To these methods I may also add that a mixture of dry nitrite of potash and hydrochlorate of naphthylamine, if gently warmed, yields azodinaphthyldiamine without difficulty, and only contaminated with chloride of potassium and the excess of nitrite employed. I have now to announce an altogether new and very interesting method of obtaining this compound-one which, I think, is calculated to throw a new light on the atomic constitution of naphthylamine. I observed, when previously working on these compounds, that naphthylamine is soluble in concentrated sulphuric acid, but that, on diluting this solution, I could not succeed in making it crystallise. As it is a well known fact that naphthylamine-salts frequently assume a colloid form, I did not investigate the causes of this phenomenon. Some observations, which I subsequently made, led me to examine this solution more carefully. I dissolved naphthylamine in cold concentrated sulphuric acid, and allowed it to stand over night. On examining it next morning, I found that it was perfectly colourless, and on diluting it with water and adding potash, a red precipitate was produced, instead of the white one, which might have been expected. This red precipitate, on the addition of acids, assumed a violet colour and was in short, azodinaphthyldiamine. I naturally suspected oxides of nitrogen to be present in the sulphuric acid employed. This, however, was not the case. I then warmed some of the original solution. It became brilliantly green, the upper surface of the fluid being violet. On being poured into water, it did not immediately mix with it, and when it did mix, it turned violet. The violet colouring matter gradually separated out and was filtered off. It presented all the characters of a salt of azodinaphthyldiamine. These characters are, insolubility in water, solubility in alcohol, the solution being a most magnificent violet, which is changed to an orange on the addition of an alkali; the original colour is re-obtained by the addition of an acid: if the acid be added drop by drop, the colour passes through various shades of red, crimson, and lilac before it re-assumes the original violet colour. It dissolves in concentrated sulphuric acid with a very beautiful blue colour. From this solution it is precipitated unaltered on the addition of water. As many persons might consider the reactions of azodinaphthyldiamine insufficient to establish its identity with the substance described in this paper, I have, with great labour, succeeded in obtaining a well crystallised sample, and determined the percentage of nitrogen it contained. It yielded the following numbers: 6405 of the base gave 77.5 c. c. N. (moist). Bar 755. Temp. 14° C. .. 75 4 c. c. at 760 bar. and 0° C. .. % of N. in substance 14.75. The preceding observations naturally led to a general examination of the action of acids on naphthylamine. The acids employed were the following:-Nordhausen sulphuric acid, and common sulphuric acid, phosphoric acid (obtained from the residue in the preparation of iodide of ethyl, and, therefore, free from all suspicion of oxides of nitrogen), oxalic, acetic, tartaric, citric, nitric, hydriodic, and hydrochloric acids. All these acids, with the exception of hydrochloric acid, when boiled with water and naphthylamine, produce colourless or but slightly coloured compounds, which, by the action of potash, yield azodinaphthyldiamine. The nitric acid must, of course, be used dilute. The other acids appear to act best when concentrated, and indeed the largest yield is obtained by fusing together naphthylamine and oxalic acid. The resulting compound must be dissolved in boiling water, and precipitated with potash, carbonate of potash, or in some cases ammonia*. Curiously enough, I could not make hydrochloric acid produce this conversion of naphthylamine into azodinaphthyldiamine. On a consideration of this reaction, it is evident that at least three equivalents of naphthylamine must be concerned in the formation of one of azodinaphthyldiamine, and that there must also be secondary products formed. course the simplest view of the case is that three equivalents of naphthylamine coalesce, and that C10H12 is in some manner eliminated from them by the action of the acid. I have not yet succeeded in isolating the secondary product. Of Ammonia will answer in the case of sulphuric acid, but gives a colourless solution with the oxalic acid. I have not tried its action with any of the other acids. Aniline (crude) apparently behaves in a similar manner, though I have not examined its action with any acid excepting sulphuric acid. If naphthylamine be boiled with dilute sulphuric acid, the resulting colourless solution need not be treated with an alkali or an alkaline carbonate; acetate or oxalate of potash produces the same effect, though of course the acetate or oxalate of the base is obtained instead of the base itself. Sometimes the colourless solution obtained by boiling the naphthylamine with excess of acid yields only traces of the base on the addition of an alkali; nevertheless, the base itself may easily be obtained from such a solution by re-acidifying and reprecipitating. When naphthylamine is heated with excess of hydrochloric acid, it yields, as usual, a colourless solution, which yields a red base by the addition of an alkali. This base, however, is not turned violet by the addition of an acid, but again becomes colourless. The only body, known to me, derived from naphthylamine having this peculiarity is ninaphthylamine. I have not examined the body, and cannot, therefore, do more than suggest the possibility of this red base being ninaphthylamine. I have worked with ninaphthylamine, and the substances present precisely similar appearances. It has often been remarked, on attempting to recrystallise salts of naphthylamine, that they are apt to lose their power of crystallisation, and to become gummy. It is also well known that solutions of these salts cannot be kept without undergoing a similar change. On examining the mother-liquor from which the sulphate had been crystallised, I found that it yielded azodinaphthyldiamine by the action of alkalies. Every one who has ever worked with naphthylamine must have observed that filter-papers, cloths, and, in fact, everything which comes much in contact with the solutions, assumes a reddish or violet colour, and I have observed that such papers may be turned orange by the action of an alkali, and regain their violet colour when acted upon by acids. It would appear, therefore, that this coloration is due to azodinaphthyldiamine. 4. Production of Acetic and Propionic Acids from Amylic Alcohol. By ERNEST T. CHAPMAN. THE starting point of the following investigation was nitrite of amyl. This substance was prepared from the alcohol by the action of nitrous acid in the usual manner. It was found to boil constantly at 98° C., with the barometer at 750 mm. The nitrite having been very carefully dried, was treated with anhydrous phosphoric acid. A violent reaction at once took place. The mixture became very hot-so hot that in one instance it took fire. The reaction may, however, be rendered quite manageable by cooling the vessel with water, and adding the nitrite little by little. Care should be taken not to add excess of nitrite. The reaction is not accompanied by disengagement of gas. The product is a brown solid mass. A portion of it was heated with strong solution of potash. The distillate had a mouldy, ammoniacal smell, and strong alkaline reaction. It was rendered slightly acid with hydrochloric acid, evaporated almost to dryness, and bichloride of platinum was added in excess. A precipitate was soon formed. It was washed, dried, and the percentage of platinum determined. It corresponded with ammonio-bichloride of platinum. The filtrate was then rendered slightly alkaline with potash when the mouldy smell was again produced; it has considerable resemblance to patchouli. On rendering the fluid strongly alkaline and heating, the smell of ammonia was again perceived. The mixture was then distilled, the distillate mixed with excess of strong potash, and heated in a sealed tube for about an hour at 120° C. When the tube was opened, gas escaped, and there was a strong smell of ammonia, but the mouldy smell had disappeared. The contents of the tube were rendered acid with sulphuric acid, transferred to a small retort, and distilled. The distillate was free from sulphuric acid, but had a strongly acid reaction. It tasted and smelt like acetic acid. Another portion of the original substance was heated with caustic potash in such a manner that the fluid distilling off flowed back again on to the potash. Ammonia |