distinct crystals, which, however, are generally very thin and scaly, so that their form cannot be ascertained with exactness. It has been observed that most of the salts of chrysammic acid are identical in form when examined under the microscope; generally they appear in the well known twin combinations so characteristic of gypsum.

Hydrochrysummide.

In addition to the processes already known for preparing this beautiful body, it may very readily be obtained by digesting pure chrysammic acid with zinc and a dilute acid, or by the action of hydriodic acid, to which a small piece of phosphorus has been added to prevent the separation of free iodine. Also on bringing chrysammic acid suspended in water in contact with sodiumamalgam, a purple solution containing hydrochrysammide is formed; and when this is shaken up in a well closed bottle with an excess of the amalgam, the purple colour soon changes into orange, but on admitting even the smallest amount of air, the purple colour is restored.

XXIX.-On Chrysammic Ether.

By JOHN STEN HOUSE, LL.D., F.R.S., &c.

THIS ether is prepared by a process similar to that which I have previously described for styphnic ether, although it is much more difficult to obtain in a state of purity.

Pure chrysammic acid, obtained from chrysammate of calcium, is boiled with about twelve times its weight of water, and a concentrated solution of carbonate of sodium is added by degrees until the whole of the acid is dissolved, and the solution is slightly alkaline. Care should be taken to avoid any great excess of the carbonate, as it decomposes the chrysammic acid. When the chrysammate of sodium has completely crystallised out, which takes place in about 16 hours, it is collected and washed with a little cold water, and is rendered quite pure by re-dissolving in a small quantity of boiling water, filtering, and allowing to crystallisc. The best method of obtaining the chrysammate of silver required for the preparation of the ether is to precipitate a solution of chrysammate of sodium in 50 parts warm water by a

STENHOUSE ON CHRYSAMMIC ETHER.

slight excess of nitrate of silver, collect on a filter when cold, wash well with cold water, and dry at a gentle heat.

Chrysammic ether.-Chrysammate of silver prepared by the above process, and previously dried for half-an-hour at 100°, is introduced into a flask furnished with a long condensing-tube; five times its weight of dry iodide of ethyl is poured on it; and the whole is digested for 10 or 15 minutes in a water-bath. The long condensing-tube is now replaced by a bent one, and the excess of iodide of ethyl distilled off, leaving a residue of iodide of silver and chrysammic ether in the flask.

On digesting this with benzol, the latter is dissolved, and crystallises out on cooling in hard dark brown crystals. These are finely powdered and recrystallised four or five times from benzol A final recrystallisation until they assume a pale yellow colour. from alcohol renders them pure. In all these operations great care must be taken to avoid the presence of moisture, as otherwise the ether is partially decomposed, and its purification consequently rendered very difficult.

Pure chrysammic ether crystallises from spirit, in which it is not very soluble, in tough needles of a pale red colour. Out of benzol, in which it is tolerably soluble, it separates in the form of hard yellow prisms. It is nearly insoluble in bisulphide of carbon, and but slightly so in ether. When heated in a tube, it melts, but is at the same time decomposed. On platinum-foil it burns without deflagration.

The ether, crystallised from spirit and dried at 100°, gave the following results when subjected to analysis:

I. 239 grm. substance gave 399 grm. carbonic acid and 056 grm. water.

II. 324 grm. substance gave 532 grm. carbonic acid and

075 grm. water.

45.54

45.16

28

H6

6

2.52

2.57

96

238

These results, as will be seen, agree very well with the

formula C,NHO,

XXX.-CONTRIBUTIONS FROM THE LABORATORY OF THE LONDON INSTITUTION.

1. The Oxidation-products of the Propione produced from Carbonic Oxide and Sodium-ethyl.

By J. ALFRED WANKLYN.

THE progress of research has shown that the various ketones are characterised by their oxidation-products. I have, accordingly, oxidized the propione which is obtained by the action of carbonic oxide on sodium-ethyl.

The mode of preparing this propione has been already described. Before employing the propione, I submitted it to a careful fractionation, so as to remove the liquid of high boiling point which accompanies it in its crude state. It was distilled ten times, and then heated in a current of dry carbonic acid to expel traces of ether.

After this preparation, I scaled some of it in a tube, together with excess of bichromate of potash and dilute sulphuric acid, and heated the whole in the water-bath for several hours. On opening the tube, no gas escaped, showing that carbonic acid is not among the oxidation-products. Moreover, the contents of the tube had the well-known smell of the acetic acid series.

After distilling and re-distilling, a distillate was obtained free from sulphates. This distillate was treated with carbonate of baryta, which dissolved very readily. An excess of the carbonate was then added and the liquid boiled and filtered.

The resulting solution of baryta-salt was evaporated to dryness in the water-bath, and the residue dried at 110° C.

Baryta determinations were made.

I. 0-3922 grm. of the barium-salt was ignited, when it evolved abundance of organic matter, and gave 2804 grm. of carbonate of baryta. Percentage of barium = 49.77.

II. 0-6266 grm. of the barium-salt was precipitated with dilute sulphuric acid, and the resulting sulphate of barium separated by filtration, washed, dried, and ignited. The sulphate of barium weighed 0.5295 grm. Percentage of barium = 49.74.

*Chem. Soc. J. [2], iv, 13 (1866).

The theoretical percentages of barium in the propionate and acetate are exhibited as follows:

Ba

Thus the percentage of barium is seen to be intermediate. between that required by propionate, and that required by acetate, of barium.

Some of the barium-salt was carefully tested for formiates, which proved to be absent. It is, therefore, certain that the barium-salt consisted in part of acetate. A portion of the barium-salt was decomposed with an equivalent of dilute sulphuric acid, and the organic acid thus obtained was about half saturated with carbonate of soda and distilled. From the distillate a barium-salt was made.

0.2066 grm. of this barium-salt gave, on ignition with sulphuric acid, 0.1728 grm. of sulphate of barium. Percentage of barium

49.24, which approximates sufficiently to the number required by propionate of barium. It will be apparent that had there been higher acids present, a treatment of this kind would have furnished a barium-salt having an entirely different composition.

The sodium-salt resulting from this partial saturation was distilled with dilute sulphuric acid. The distillate had all the characters of acetic acid, giving cacodyl when a salt of it was heated with arsenious acid, and acetic ether on treatment with alcohol and concentrated sulphuric acid.

There is, therefore, no doubt that propione is resolved quite simply into propionic and acetic acids, when it is oxidized with bichromate of potash and dilute sulphuric acid. This is, I believe, the first example of a ketone being resolved into acids of less carbon-condensation than itself, without at the same time giving rise to carbonic acid.

The generation of propionic and acetic acids from propione without production of carbonic acid is quite in accordance with theory.

It is not improbable that the first stage of the process consists in the formation of propionate of ethyl, e. g.,

and that there should be great difficulty in arresting the progress of the oxidation so as to exhibit the ether. Be this, however, as it may, the connection between the mode of origin of propione, and the production of its oxidation, deserves remark. Formed directly from carbonic oxide and ethyl, it admits of oxidation into acetic acid-the oxidation-derivative of the ethyl series-and propionic acid the oxidation-derivative of the propyl series. The oxidation of propione, an isomer of valeral (CH10O), gives no acid higher in the scale than propionic acid.

2. On the Oxidation of Ethylamine.

By J. A. WANKLYN and ERNEST T. CHAPMAN. WHEN ethylamine or sulphate of ethylamine is treated with bichromate of potash and sulphuric acid, little or no action takes place in the cold, even on long standing. On boiling, however, the ethylamine is attacked, though only slowly. As the solution becomes more concentrated, the reaction becomes brisker, and towards the end of the operation much gas is evolved. When the liquid has almost all distilled off, a reaction like that which takes place with ammonia and chromic acid occurs. Sulphate of ethylamine was boiled with bichromate of potash and dilute sulphuric acid. The vapours evolved passed first through a Liebig's condenser, and then into a receiver kept cool by ice and salt. The distillate was heated till a small quantity had distilled over. It smelt like aldehyde, and with it we obtained the ordinary reactions of that substance, viz., formation of the silver mirror, and of the ammonia-compound.

The liquid which remained in the retort presented all the