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 BI_{3}, crystallizing from solution in carbon bisulphide in pearly tables, which melt at 43 deg. to a liquid which boils undecomposed at 210 deg..  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 deg. and 200 deg..  When heated in vacuo it commences to volatilize about 170 deg., and the vapor condenses in the cooler portion of the tube in beautiful red crystals.  Analyses of these crystals agree perfectly with the formula BPI_{2}.  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