LUMINOUS PAINT.

Hugo Lieber, of New York, N. Y. Patent No. 791,631, dated June 6, 1905.

The preferred form of composition is self-luminous, but fireproof and tenacious. One form contains a composition of zinc sulphide and radium-barium carbonate mixed with a body formed of soluble cotton and wood-alcohol, acetone, and castor-oil. These are preferably mixed in the following manner: First, about six parts of alcohol are mixed with two parts of acetone. Then the soluble cotton is dissolved in the fluid in proportion of about one pound of cotton to three gallons of the fluid. Next about a pint of oil is mixed with one gallon of the prepared mixture. This completes the body. Then the sulphide is mixed in the proportion of one ounce to six ounces of the prepared body. The radium compound is preferably added to the luminescent material before mixing with the body. The resultant composition dries very quickly, is highly luminous, non-inflammable, and tenacious. It, in fact, acts as a fireproofing to any surface to which it may be applied and yet is highly luminous. The alcohol and the soluble cotton form a durable and adhesive body. The acetone assists the alcohol in solution and increases the flexibility of the applied composition. The oil greatly increases the smoothness and dries quickly. The zinc sulphide is highly luminescent and with the acetone entirely counteracts the inflammability of the cotton. The radium compound increases and maintains the luminosity of the composition by exciting the sulphide. Amyl acetate may be substituted for the acetone in the body. The resultant body is transparent and gives superior results in color and luminosity.

CATALYTIC APPARATUS FOR MAKING SULPHURIC ANHYDRID.

Georg Eschellmann and Albert Harmuth, of St. Petersburg, Russia, assignors to Tov. Tentelevskago Ximichesk Zavoda. Patent No. 792,205, dated June 13, 1905.

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This invention relates to improvements upon apparatus for the manufacture of sulphuric anhydrid from sulphurous-acid gas and oxygen or atmospheric air by the agency of suitable catalytic substances, and especially upon apparatus of this kind in which a large chamber is arranged in front of the catalytic substance contained in a system of tubes (called catalytic tubes ") and is supplied through an opening in its top with the gaseous mixture to be treated from a preheater in which the said mixture is heated according to the indications of a thermometer placed in said large chamber in the zone next to the upper extremities of the catalytic tubes. The purpose of arranging said large space or chamber in front of the catalytic substance is to enable the latter to automatically prevent accumulation of surplus heat within it by at once transferring the same by radiation to a large body of gases. Now it is found that the efficiency of said apparatus will be considerably increased by subdividing the catalytic substance into two portions, arranging one portion as a uniform even layer in front of the tubes, which are filled with the remaining portion of the catalytic substance, and protecting the catalytic tubes against losses of heat, while the upper layer is allowed to freely radiate heat into the large gas-chamber in front of it. With this subdivision and modified arrangement of the catalytic substance in an upper portion which is cooled by radiation and a lower portion which is protected against cooling the same quantity of catalytic substance as used in the older apparatus has proved to be able to transform from ninety-five to ninety-seven per cent. of the sulphurous-acid gas presented to it into sulphuric anhydrid with the assistance of but one-half of that amount of power which it is necessary to apply when all of the catalytic substance is placed in the tubes as in the older apparatus. This rise of efficiency obtained by the described modified arrangement of the catalytic substance is believed to be principally due to the increased heat-radiating capacity of said substance resulting from the increased surface given to the upper portion thereof by spreading out the same over a by far larger surface than that

which the catalytic substance will present to the body of gases in front of it when exclusively contained in tubes.

PROCESS OF MANUFACTURING FILAMENTS FROM VISCOSE.

Charles A. Ernst, of Lansdowne, Pennsylvania, assignor to Silas W. Pettit, Philadelphia, Pennsylvania. Patent No. 792,888, dated June 20, 1905.

In this process the spinning-bath comprises a dehydrating reagent which is otherwise inert toward the viscose, the preferred ingredient being wood-alcohol. With this is combined an organic acid and a salt of an organic acid in solution in such acid, the preferred reagents being acetic acid and sodium acetate. As a working formula for a bath thus constituted with ordinary commercial wood-alcohol about six per cent. of acetic acid should be added and the mixture substantially saturated with sodium acetate. Glacial acetic acid is preferably employed in order to minimize the incidental addition of water. The viscose is discharged into this bath in the usual manner through the spineret, and the spun filaments are wound immediately after their emergence from the setting-bath. The complete reversion of the viscose is then effected, preferably, by immersion in a bath containing an inert dehydrating reagent and an organic acid alone. For this bath wood-alcohol and glacial acetic acid are used in the proportions above stated for those ingredients. The reverted filament is then washed and dried.

CATALYTIC APPARATUS FOR MAKING SULPHURIC ANHYDRID.

Max Schroeder, of Düsseldorf, Germany, assignor to the New Jersey Zinc Company. Patent No. 793,543, dated June 27, 1905. This invention relates to certain new and useful improvements in the manufacture of sulphuric anhydrid (SO,) by the so-called

"contact" process, wherein the gases from roasting-furnaces or the like and which contain varying quantities of sulphurous anhydria (SO2) and oxygen are caused to pass through apparatus containing a contact mass whose catalytic action causes a union of the sulphurous anhydrid and oxygen and the consequent production of the sulphuric anhydrid, which latter is recovered by absorption.

The characteristic feature of the present improvement consists in avoiding the difficulties due to heat radiation in apparatus of the type referred to by a construction wherein the gases which pass in contact with the walls of the apparatus and the gases which pass through the central portion of the contact mass are mixed at least once, and preferably several times, on their passage therethrough. By this expedient the excessively-cooled gases which pass in contact with the walls of the apparatus are from time to time intimately intermingled With the hotter gases traversing the interior of the mass, so that an average temperature is established for the mixture. Because of the relatively smaller volume of the excessively-cooled gases, this average temperature is still sufficient to maintain the most favorable conditions for the catalytic action of the contact mass upon the entire volume of SO, present.

PROCESS OF EXTRACTING TANNING SUBSTANCES. Georg Ferdinand Bögel, of Altona, Germany. Patent No. 794,847, dated July 18, 1905.

This invention relates to a process for the continuous extraction of tanning materials within a battery of centrifugals. To obtain a thorough extraction, even with short batteries, only a part of the substances thrown off from one centrifugal is conveyed to the succeeding centrifugal, while the remainder is returned to the first centrifugal. The comminuted tanning material is introduced into a number of centrifugals placed side by side. Fresh water is supplied to one of the centrifugals, which by the rotation of the latter is driven through the layer of tanning material that accumulates

upon its wall, so that the water becomes enriched by the tannin. The thrown-off and accumulated lye is then pumped partly into the next centrifugal and partly back into the first centrifugal, where it is again driven through the layer of tanning material, and so on through the entire series. From the last centrifugal half of the lye passes into the discharge-pipe, while the other half passes back into the last centrifugal. In this way a complete extraction of the tanning material may be obtained without injuriously affecting the same.

MANUFACTURE OF ARTIFICIAL THREADS FROM SOLUTIONS OF CELLULOSE.

Rudolf Linkmeyer, of Herford, Germany. Patent No. 795,526, dated July 25, 1905.

This process consists, broadly, in first of all producing in a first weak bath of ammoniacal oxid of copper a swelling of the fibres and a deposit of oxid of copper upon them and in then effecting solution in a concentrated solution of ammoniacal oxid of copper. In this manner a solution is obtained the very pronounced viscosity of which is extremely advantageous for spinning.

It has been found that the solution of the cellulose is effected very efficiently if the cotton, bleached or boiled for some hours, is first of all placed, either in a dry or humid condition, in a weak bath of ammoniacal oxid of copper, to which may be added with advantage a small quantity of caustic soda. This first bath serves to soften, swell, and disintegrate to some extent the fibres and to fix upon them the oxid of copper dissolved by the ammonia. The fibres then dissolve speedily and readily in a concentrated solution of ammoniacal oxid of copper. By proceeding in this manner the conversion of the cellulose into oxycellulose or the hydration of the fibres is avoided. Further, the success of the solution depends less upon the temperature than upon the other processes. Solution takes place equally well at 10° to 15° C. as at a lower temperature.