To further elucidate the action of the alkali under the conditions given above, the author has estimated the amount of precipitate which alcohol gives with the soda solutions, after boiling with the wood:
| 1. | 2. | 3. | ||||
|---|---|---|---|---|---|---|
| Specific gravity of NaHO solutions | 1.043 | 1.09 | 1.162 | |||
| Soft wood, | ordinary pressure | 1.043 | traces | 4.8 | ||
| " | pressure of | five | atmospheres | 1.043 | 2.0 | 26.8 |
| " | " | ten | " | 1.043 | 1.7 | — |
| Hard wood, | ordinary pressure | 11.10 | 27.40 | 30.80 | ||
| " | pressure of | five | atmospheres | 1.10 | 25.70 | 15.8 |
| " | " | ten | " | traces | 5.20 | 15.8 |
The estimation of the precipitate, produced in the soda solutions employed in the experiments cited above, gives:
| Soft wood, | ordinary pressure | 1.31 | traces | 2.0 | ||
| " | pressure of | five | atmospheres | 15.94 | 16.0 | 24.80 |
| " | " | ten | " | 17.00 | 25.4 | — |
| Hard wood, | ordinary pressure | 5.40 | 6 | 5.60 | ||
| " | pressure of | five | atmospheres | 9.40 | 15.40 | 33.60 |
| " | " | ten | " | 14.00 | 18.40 | 33.60 |
As a general rule manufacturers employ a greater pressure than that which was found necessary by the author. As a result, it appears from these experiments that the wood not only loses incrusting matter, but that part of the cellulose enters into solution. As a matter of fact, the yield obtained in practical working from 100 parts of wood does not exceed 30 to 35 per cent.—Le Bull. Fab. Pap.; Chemical Trade Journal.
NEW BORON COMPOUNDS.
An important paper is contributed by M. Moissan to the current number of the Comptes Rendus, describing two interesting new compounds containing boron, phosphorus, and iodine. A few months ago M. Moissan succeeded in preparing the iodide of boron, a beautiful substance of the composition BI3, crystallizing from solution in carbon bisulphide in pearly tables, which melt at 43° to a liquid which boils undecomposed at 210°. When this substance is brought in contact with fused phosphorus an intense action occurs, the whole mass inflames with evolution of violet vapor of iodine. Red phosphorus also reacts with incandescence when heated in the vapor of boron iodide. The reaction may, however, be moderated by employing solutions of phosphorus and boron iodide in dry carbon bisulphide. The two solutions are mixed in a tube closed at one end, a little phosphorus being in excess, and the tube is then sealed. No external application of heat is necessary. At first the liquid is quite clear, but in a few minutes a brown solid substance commences to separate, and in three hours the reaction is complete. The substance is freed from carbon bisulphide in a current of carbon dioxide, the last traces being removed by means of the Sprengel pump. The compound thus obtained is a deep red amorphous powder, readily capable of volatilization. It melts between 190° and 200°. When heated in vacuo it commences to volatilize about 170°, and the vapor condenses in the cooler portion of the tube in beautiful red crystals. Analyses of these crystals agree perfectly with the formula BPI2. Boron phospho-di-iodide is a very hygroscopic substance, moisture rapidly decomposing it. In contact with a large excess of water, yellow phosphorus is deposited, and hydriodic, boric, and phosphorus acids formed in the solution. A small quantity of phosphureted hydrogen also escapes. If a small quantity of water is used, a larger deposit of yellow phosphorus is formed, together with a considerable quantity of phosphonium iodide. Strong nitric acid oxidizes boron phospho-di-iodide with incandescence. Dilute nitric acid oxidizes it to phosphoric and boric acids. It burns spontaneously in chlorine, forming boron chloride, chloride of iodine, and pentachloride of phosphorus. When slightly warmed in oxygen it inflames, the combustion being rendered very beautiful by the fumes of boric and phosphoric anhydrides and the violet vapors of iodine. Heated in contact with sulphureted hydrogen, it forms sulphides of boron and phosphorus and hydriodic acid, without liberation of iodine. Metallic magnesium when slightly warmed reacts with it with incandescence. When thrown into vapor of mercury, boron phospho-di-iodide instantly takes fire.
The second phospho-iodide of boron obtained by M. Moissan is represented by the formula BPI. It is formed when sodium or magnesium in a fine state of division is allowed to act upon a solution of the di-iodide just described in carbon bisulphide; or when boron phospho-di-iodide is heated to 160° in a current of hydrogen. It is obtained in the form of a bright red powder, somewhat hygroscopic. It volatilizes in vacuo without fusion at a temperature about 210°, and the vapor condenses in the cooler portion of the tube in beautiful orange colored crystals. When heated to low redness it decomposes into free iodine and phosphide of boron, BP. Nitric acid reacts energetically with it, but without incandescence, and a certain amount of iodine is liberated. Sulphuric acid decomposes it upon warming, without formation of sulphurous and boric acids and free iodine. By the continued action of dry hydrogen upon the heated compound the iodine and a portion of the phosphorus are removed, and a new phosphide of boron, of the composition B5P3, is obtained.—Nature.