The oil to be purified is fed in any convenient manner into the slightly conical vessel V, with cover Q, to the lower end of which are bolted short annular sections carrying the filtering sheets D, D', and D. The vessel is surrounded by a double casing consisting of an outer shell A and an inner perforated liner B, carrying a steam coil C between them. The vessel and its casings are mounted on the top of a receptacle F for the purified oil, which, preferably, is fitted with an additional filtering sheet E. The receptacle is provided with a gauge-glass for ascertaining the level of the purified oil G, and has a three-way cock I below, communicating with the lower part of the oil reservoir through a short raised tube surmounted by a strainer. Any water or sediment contained in the purified oil sink below the raised tube, and can be drawn off through the taps J and L, whilst the purified oil is drawn off through the tap I.-B.

Improvements in Apparatus for Wholly or Partially Separating Liquids from Solids. S. K. Welsh, London, and J. H. Godman, St. Albans. Eng. Pat. 1591, January 27, 1892.

A HOLLOW cylindrical drum is suspended on horizontal trunnions within a cistern partly filled with the liquid to be filtered. The circumference of the drum is perforated and its interior divided into compartments by radial partitions. The central part of one side of the drum is kept in close contact with the inside of the cistern, through which several ports are cut for the exit of the filtered water issuing from corresponding apertures in the side of the drum. Each of

the holes in the side of the cistern is in connexion with a separate receptacle for the filtered liquid in which a vacuum may be maintained for accelerating the passage of the liquid, each succeeding receptacle being kept under a higher vacuum than the previous one. Over the perforated circumference of the drum is laid an endless moving band of cloth or other permeable material, covering the drum to a height above that of the unfiltered liquid in the cistern, and being thence taken over rollers which carry it past rotary brushes or other cleaning apparatus with a view to removing any deposit left on the cloth.-B.

Improvements in Apparatus for Heating Furnaces or other Appliances for Metals, Glass, or other Materials, J. A. Yeadon and W. Adgie, Leeds. Eng. Pat. 2460, February 9, 1892.

THE revolving retort described in a previous specification (Eng. Pat. 19,183, this Journal 1890, 797) is charged with carbonaceous matter and heated, preferably with its own crude gases, and the gas produced in this way is applied either crude or purified, mixed with air, or with water-gas, or other gases for heating any kind of furnace for any of the purposes mentioned above.---J. H. C.

Concentration of Liquors and Utilization of Steam arising therefrom. W. J. Mirrlees and A. J. Liversedge, Glasgow. Eng. Pat. 3257, February 19, 1892.

IN the concentration of liquors such as are treated in the manufacture of sugar, caustic soda, and other products, the inventors heat the liquor in one vessel by means of steam from a boiler, and use the vapour arising from the concentrated liquor for heating other liquors in separate vessels in which secondary or supplementary operations are to be effected.-B.

Improvements in and connected with the Method of and in Apparatus for Drying Peat, Manure, and Similar Matters. W. Bowler and J. Bradbury, Manchester. Eng. Pat. 6442, April 4, 1892.

THE materials to be dried are spread on a series of horizontal surfaces or shelves arranged within a furnace through which hot air or other gases circulate. The materials are moved along the surfaces by endless chains in a direction opposite to that of the current of air, dropping at alternate ends to the next lower shelf, and are fed into and taken out of the furnace through the action of rotary valves.-B.

Improvements in the Process of Treating Cork and Apparatus therefor. H. J. Haddan, London. From J. T. Smith, New York, U.S.A. Eng. Pat. 18,199, October 11,

1892.

THIS invention relates to the treatment of cork for industrial or other uses. For this purpose moulds are employed which are made in sections, which, when in use, are held together by clamps. The cork is introduced into these moulds and there subjected to high pressure, and such a degree of heat as will cause the resinous matters contained in cork to melt or evaporate, thus cementing the separate pieces of cork together.-C. O. W.

Improvements in Apparatus for Controlling the Flow of Acid or other Liquid to and from Casks or other Receptacles. A. H. Wendt, Gelnhausen, Germany. Eng. Pat. 19,837, November 3, 1892.

A is the tank from which the acid is to be raised to a higher level throngh the ascending pipe B. The casing C contains a ball-valve E in connexion with a piston-valve F, which latter opens or shuts off the pipe G through which air under pressure can be let into the tank for raising the acid to the desired level. The pipe D leads to an acid reservoir which is placed at a somewhat higher level than

PATENTS.

Improvements in Washing and Preparing and Coking of Smudge, Slack, or other Coal, and in the Application of the Gases resulting therefrom, and in Apparatus therefor. D. Rylands and H. Naylor, Barnsley, Yorks. Eng. Pat. 471, January 9, 1892.

SMUDGE, slack, or coal is delivered on to an inclined trough, the inclination of which can be adjusted, and is carried forward by a stream of water. Movable partitions are placed along the trough at intervals. The heavier impurities are arrested by the partitions, and the coal passes onwards through similar troughs and is deposited in perforated hoppers furnished with perforated pockets to assist drainage. When the cavities formed by the partitions are full the supply of coal is discontinued and the partitions are removed one by one, beginning with the highest. The stream of water then carries the stony matter forward and it eventually drops through a valve opened in the end of the trough. The coal-washing operations are then recommenced. The washed coal in the hoppers is either discharged into trucks or on to a conveyor. The first portion of the latter has perforated sides and a bottom sloping from the centre outwards; the second portion is not perforated, but is steam-jacketed to complete the drying of the coal. The conveyor is also provided with drive-chains to which scraper-plates are attached for the turning over of the coal. The coal after washing can be used for coking. In the latter operation the hot gases from the ovens are used to heat steel crucibles placed in the flue, air being admitted if necessary. The gases are then used for heating purposes. -H. K. T.

Improvements in Coke Ovens. J. Mitchell, Barnsley Yorks. Eng. Pat. 1647, January 27, 1892.

IN the side of an ordinary coking-oven three or more flues or passages are made for the purpose of admitting air for the combustion of the gaseous products given off. The passages are placed above the clearing-hole and gradually decrease in depth and increase in width from the outside inwards, so that the air, which is admitted just above the top of the coal, is spread out in a thin sheet. The centre passage is horizontal, the lateral ones incline upwards. The bricks by which they are formed are preferably made in two pieces and are shaped to suit the curvature of the oven.-H. K. T.

Improvements in the Manufacture or Production of Water Gas and Apparatus therefor. S. Fox, Leeds. Eng. Pat. 1804, January 29, 1892.

In order to shorten the time occupied in heating a watergas generator, the patentee employs a hot instead of a cold air-blast; the air necessary for this purpose is raised to a high temperature in a regenerator which has been heated by hot gases from the water-gas generator. A single regenerator divided into two chambers or two separate regenerators are employed so that the apparatus may be worked continuously.-F. S. K.

Improvements in and Connected with the Manufacture of Illuminating Gas. W. H. Wilson, Liverpool. Eng. Pat. 2073, Feb. 3, 1892.

WITH the object of increasing the quantity of gas made from any kind of coal or other material, and at the same time of obtaining a higher illuminating power, the mouthpieces and ascension pipes of the ordinary gas retorts are heated in such a way that no pitch is deposited in them; the heating may be conveniently accomplished by surrounding the parts mentioned with brickwork or metallic sheeting provided with flues, through which the waste gases from the retort bench are passed.-F. S. K.

Improvements in Furnaces. E. G. Brewer, London. From La Societé E. Herrmann and Cohen, Paris, France. Eng. Pat. 12,930, July 14, 1892.

THE grate of this furnace consists of four parts—B, C, G, and D. The fuel is forced into the furnace from the hopper A by means of the rotary feeder R, and is first supported by the grate B and the upper part of C. It here undergoes partial combustion by means of the air supplied through the lateral orifice G" and the orifices at g. The latter air supply is separated by means of the plate g from that entering lower down through the butterfly valves of the furnace door.

and then forms a platform which facilitates the removal of the clinker. The combustion is regulated by adjusting the air supply arriving through g and through the valves of the furnace door.-H. K. T.

Process of and Apparatus for Preparing Tar, Oil, Paraffin, Pitch, Heating and Illuminating Gases, and Large Coke from Fibrous Organic Materials such as Peat and Lignite. P. Jensen, London. From M. Ziegler, Nachterstedt, Germany. Eng. Pat. 17,484, September 30, 1892.

THE most important points which need mention are those referring to the structure of the coke-oven and to the method of coking.

The coke-oven consists of a large, vertical, cylindrical space, closed at the top by means of a plug-valve, and surrounded by heating flues; this space is divided by a horizontal partition into an upper drying chamber, the walls of which are made of cast iron, and a lower coke chamber, the walls of which are of brickwork; both chambers contain an inner cylindrical column, consisting of flat, round plates, which occupy the centre of the cylindrical space from top to bottom.

Prepared blocks of turf, about 6 in. in length, and previously dried in the condensers mentioned below, are introduced into the upper chamber, and, owing to the conical top of the central column, are brought into close proximity with the heated iron walls; the water vapour evolved is drawn off by means of a suction-pump. The turf is then allowed to drop into the lower chamber, where it is converted into coke, the gases being drawn off by means of exhausters; the finished coke passes into a conical chamber, provided at its bottom or apex with a large plugvalve, and finally falls into a tank, cooled by a waterjacket, where it is quenched with steam.

The gases evolved during the coking process are passed through condensers to free them from water and tar, and are then employed for heating the coke-oven.

The working of the oven is continuous and the coke is obtained in large, firm blocks; the tar is worked up in the usual manner.-F. S. K.

VARIOUS improvements are described in this patent, the principal object being to secure economical working.

In the first place the products of combustion formed during the heating of the fuel are burnt in the usual manner in a chamber containing refractory material; the gases from this chamber, instead of being allowed to escape, are passed through the furnace of the steam-boiler which is employed in the production of the water-gas, so that a saving of fuel is effected.

In the second place the small quantity of illuminating gas which is left in the cupola at the time of the reversal of the apparatus is also utilised for the production of

steam.

Thirdly, the manufactured gas from the fixing chamber is passed through a vessel containing the pipes through which the oil is flowing under pressure to the chamber where it meets the water-gas; the oil, thus heated, is immediately vaporised on issuing from the pipes and is readily taken up by the water-gas.

Improved, moveable, hollow furnace bars, through which water circulates, are employed to obviate the frequent opening of the ash-pit door of the furnace.-F. S. K.

A New or Improved Apparatus for Carburetting Gas and Air for Illuminating and Heating Purposes. A. W. Wells, Harlesden, Middlesex. From F. Verrue, Brussels. Eng. Pat. 19,483, October 29, 1892.

THE usual method is employed for carburetting the gas or air, namely, that of passing the gas through a vessel supplied with oil; the essential features of the patent are

novel devices for ensuring the saturation of the gas and for preventing the freezing of the carburettor.

The carburettor consists of three concentric chambers, which are filled with perforated cylinders resting upon cloth. The cylinders in the outer chamber, into which the gas first enters, are filled with porous wood-fibre which is saturated with oil by capillary absorption; the cylinders in the middle chamber contain asbestos, and serve to partly free the gas from excess of oil; the innermost chamber contains cylinders filled with a bad conductor of heat, such as charcoal, and serves as a condensing chamber in which the excess of oil is completely removed. Above and below the central and middle chambers are spaces containing a bad conductor of heat to protect the chambers from changes of temperature; this object is also secured by completely surrounding the carburettor with a waterjacket.-F. S. K.

III.-DESTRUCTIVE DISTILLATION, TAR PRODUCTS, Etc.

On Pyridine Bases in Mineral Oils.

R. Zaloziecki. Monatsh. Chem. 13, 498-503. MINERAL oils contain as a rule but slight quantities of nitrogen, varying between 0:01 and 0.1 per cent., and reaching only occasionally as much as 1.1 per cent. When dealing with such small quantities, it is a difficult task to ascertain the combinations in which the nitrogen is present. So far ammonia, ammonium carbonate, and benzo-isonitrile have been discovered either in the crude oils or in their products of distillation, and lately alkaloid bases have been observed by Bandrowski in the crude oils of Slobodarungurska.

The author made further investigations on this subject. The waste acid from Boryslaw oil, as obtained at the Drohobycz works, has been diluted to 106° Tw., to separate tarry matters, the clear liquor drawn off, made alkaline with lime, whereby the original aromatic odour changes into the characteristic pyridine-like odour. On treating the mass with a current of steam, oily drops are obtained. These are separated from the water, treated with hydrochloric acid, and then with alkali, and redistilled. The oily mass possesses the smell of pyridine. It is slightly soluble in water, easily in ether, alcohol, and acids. The analysis of the platinum double salt shows the presence of several bases free from oxygen-very likely hydrated pyridine derivates-seeing that part of the platinum double salt is decomposed by hot water, according to Anderson's reaction.

This is of great interest for the genetic theories of the mineral oils, as pyridine compounds, normal or hydrated, are products of fermentation and decomposition of the animal body.-H. A.

IV.-COLOURING MATTERS AND DYES.

A New Synthesis by means of Diazo Compounds. II. R. Hirsch. Ber. 25, 1973-1975.

Is a previous paper (Ber. 23, 3705; this Journal, 1892, 354) the author has described the reaction which takes place when diazo compounds are heated with phenols, yielding in the case of diazobenzene and phenol, o- and p-hydroxy-diphenyl, diazohydroxybenzene being formed as an intermediate product. He has now extended the reaction to analogous nitrogen compounds, and states that diazoamidobenzene when heated with aniline yields amidodiphenyl and diphenylamine. The formation and decomposition of the diazoamidobenzene are carried out in one

operation. The diazo solution from 50 grms. of aniline, 150 grms. of 30 per cent. hydrochloric acid, 100 grms. of water and ice, and 39 grms. of sodium nitrite in 100 cc. of water, is mixed with 950 grms. of aniline, made alkaline with caustic soda, and the oil, after separating, dried with calcium chloride. It is then warmed in a flask to about 150° C., and the temperature gradually raised to 190°, when the greater part of the aniline distils off. When the thermometer has risen to 200° the residual cases are boiled with 10 times the weight of water and hydrochloric acid added until neutral. The liquid becomes a deep red, due to the formation of amidoazobenzene hydrochloride. Caustic soda is then slowly added when the greater part of the amidoazobenzene separates and dissolves with other impurities in the layer of diphenylamine floating on the surface. The aqueous portion separated by filtration is treated with sodium sulphate, when p-amidodiphenyl separates out as sulphate. The filtrate is made alkaline and the oil which separates fractionated; the fraction boiling above 275° C. is nearly pure o-amidodiphenyl. Both bases are purified by crystallising their salts. The yield is about 50 per cent. of the aniline used; 45 grms. of the bases were obtained whilst 900 grms. of aniline were recovered. An experiment to obtain phenylquinoline by heating quinoline with diazobenzene did not succeed, but the author states that a considerable quantity of amidoazobenzene was formed during the reaction. T. A. L.

The corresponding compounds of the methylene-blue series would be known as thiazones and thiazimes.

1. Action of Aniline on Gallocyanine. - Nietzki and Otto (Ber. 21, 1745; this Journal, 1888, 559) described a body formed by this reaction assuming that two molecules of aniline reacted with one molecule of gallocyanine with elimination of one molecule of water. Later investigations have shown that the following reaction takes place :

C15H12N2O5 + CH¿NH2 = CO2 + H2 + C20H17N3O3.

If the operation be conducted in a closed vessel, absorption of oxygen takes place, but this absorption does not appear to affect the yield, which remains the same whether the experiment be conducted in a current of air or of carbon dioxide, and is about 50-60 per cent. calculated on the gallocyanine. This absorption of oxygen does not take place in the case of the formation of the colouring matter known as " Prune" obtained by the action of aniline on gallocyanine methyl ether, the formula for which is CHNO, as already determined by Nietzki and Otto, from which it would appear to be an addition product of aniline and gallocyanine methyl ether. In the case of gallocyanine anilide a similar addition product appears to be formed when the components are ground together in the cold. The mass becomes crystalline and no carbon dioxide is given off. That this is not a simple aniline salt of gallocyanine is shown by the fact that the substance may be treated with dilute hydrochloric acid without regenerating gallocyanine. On attempting to purify the body by recrystallisation it forms gallocyanine anilide on gentle warming and it would appear that the carboxyl group is replaced by the aniline rest with evolution of

even