In conclusion I append a table of elements classified according to their atomicities as employed in this plan of notation. XL.-Synthetical Researches on Ethers.- No. 1. Synthesis of Ethers from Acetic Ether. By E. FRANKLAND, F.R.S., and B. F. DUPPA, Esq. (From the Philosophical Transactions, Vol. clvi, p. 37.) In his researches upon lactic acid Wurtz* contends with considerable force for the dibasicity of this acid, supporting his view by the transformation of monobasic into dibasic lactic ether by the consecutive action of sodium and ethylic iodide, as expressed in the following equations: * Ann. Ch. Phys. lix, 161. During the prosecution of our researches upon acids of the acetic series,† we have obtained several so-called dibasic ethers of this description; but before finally deciding upon the interpretation to be put upon such reactions, it appeared advisable to ascertain the effect of the same reagents upon a well-defined monobasic ether. For this purpose acetic ether was selected, and was treated, first, with sodium, and then with ethylic, methylic, and amylic iodides respectively. The results, although not strictly analogous with those obtained under similar circumstances with ethers of the lactic series, are highly remarkable. We have already briefly referred to them in a note presented to the Royal Society in April 1865.‡ Action of Sodium and Ethylic Iodide upon Acetic Ether. The acetic ether used for this and the succeeding reactions was made as follows: 6,000 grms. of previously dried and fused sodic acetate was broken into small pieces and placed in a copper still immersed in cold water. Over this was gradually poured 12,600 grms. of a mixture of 3,600 grms. alcohol§ of 97 per cent., and 9,000 grms. concentrated sulphuric acid, taking care that the temperature did not rise high enough to distil off any of the product. The success of the operation depends greatly upon the mode of mixing the alcohol and sulphuric acid, which ought to be performed as follows. The sulphuric acid being placed in a deep stoneware vessel of sufficient capacity, the alcohol is conducted to the bottom of it by means of a piece of narrow glass tube, connected by a caoutchouc * For an exposition of the system of notation adopted in this memoir see the preceding paper. + Proceedings of the Royal Society, xii, 396; xiii, 140; xiv, 17, 79, 83, 191, and 197. Ibid. xiv, 198. § Methylated spirit may be used for this purpose. tube with a convenient reservoir standing at a considerable elevation. The glass tube is used as an agitator during the continuance of the flow of the alcohol. In this way there is obtained, without loss of alcohol, a high temperature which greatly favours the formation of sulphovinic acid. This mixture must be allowed to stand, carefully covered up, for twenty-four hours before use. It is also advisable to make the admixture of sulphovinic acid and sodic acetate at least twelve hours before the distillation is commenced. The latter operation can then be performed over a naked fire or gas-flame, and continued till water alone passes over. In this way there was obtained 6,000 grms. of an acetic ether absolutely free from alcohol, and which, without previous washing only needs one rectification from fused and powdered calcic chloride to fit it for the action of sodium. A determination of its vapour-density gave the number 2.9. Pure acetic ether requires 3.04. When acetic ether thus prepared is placed in contact with sodium it becomes hot, and a considerable quantity of gas is evolved, which, after being passed first through alcohol and then through water, burns with a non-luminous flame, and the products of combustion do not produce the slightest turbidity on agitation with baryta-water. In fact the gas is pure hydrogen. When the action is complete, the liquid solidifies on cooling to a mass resembling yellow beeswax. By putting the sodium into the acetic ether as just described, it is difficult to conduct the operation to completion, owing to the liquid gradually assuming such a thick and pasty condition as to prevent the further action of the sodium. We therefore adopted the following modification, which enabled us to push the reaction almost to its extreme limit. A (fig. 1) is a flask containing the acetic ether, and standing in an oil-bath, B. The neck of the flask was closed with a caoutchouc cork, through which passed the beak of the quilled receiver C, containing the sodium cut up into pieces about 1 inch square and inch thick. Into the wide neck of this receiver was inserted an inverted Liebig's condenser, D, which projected sufficiently into the vessel to allow the condensed liquid to drip back upon the sodium. Heat being applied to the oil-bath, the acetic ether soon began to boil, and by its condensation in C and D not only kept the surface of the sodium constantly moist with fresh portions of acetic ether, but also dissolved off the solid sodium-compound as fast as formed. As the operation progressed it was found necessary to raise the temperature of the oil-bath, so as to cause the continuous distillation of the remaining acetic ether, which acquired a higher boiling-point as the proportion of sodium compound dissolved in it increased; but the temperature ought not to be allowed to rise above 130° C. When the acetic ether ceases to distil at this temperature, the proportion of sodium dissolved is not much below one atom for each atomic proportion of acetic D A B ether employed, and it was not found advantageous to push the reaction further. The contents of the flask were now submitted to the action of ethylic iodide, for which purpose they were transferred whilst still liquid to an iron digester, and mixed with a quantity of ethylic iodide equivalent to the amount of sodium |