such as zinc, must be in slight excess, as heretofore stated, for if even a single molecule of the acid should remain free a decomposition will take place. By thus instantaneously adding the whole quantity of the reducing-powder to the sulphurous acid the temperature of the liquid mass suddenly rises. It is not necessary to prevent this by cooling, as, if not excessive, it is essential for instantaneously and completely succeeding with the reaction. This rapid action at an elevated temperature is of great importance, for the product is easily decomposed if the whole of the acid is not transformed. After having brought the reaction to an end, allow the slight undissolved excess of the reducing-powder and the impurities that might be present in spite of all precautions to deposit and decant the liquid. The zinc hydrosulphite thus obtained is ready to be used in reducing indigo or for other purposes, or the solution can be transformed into other hydrosulphites by addition of either bases, like lime, sodium hydrate, baryta, &c., or salts acting by double decomposition, such as acetate of calcium or of barium or the like.

PROCESS OF MAKING HYDROCYANIC ACID FROM IRON-CYANOGEN COMPOUNDS.

Walther Feld, of Hönnigen-on-the-Rhine, Germany. Patent No. 792,889, dated June 20, 1905.

This invention is based on the discovery that mercuric chloride is more suitable than mercuric oxide or mercuric sulphate for manufacturing hydrocyanic acid from iron-cyanid compounds. First, the decomposition of the iron-cyanid compounds is more complete by mercuric chlorid; secondly, metallic mercury will not be separated, because in decomposing ferricyanid compounds no reduction enters, whereas in decomposing ferrocyanid compounds the mercuric chlorid (HgCl2) used is only reduced to mercurous chlorid, (HgCl2,) but not to metallic mercury, and, thirdly, the mercuric chlorid can be used in neutral, acid, or alkaline solution. This process is adapted for application to all materials containing iron-cyanid compounds-for example, gas-purifying materials,

Prussian blue, ferrocyanid and ferricyanid compounds, &c. It is unimportant whether the compounds are soluble or insoluble.

For carrying out the invention the materials to be decomposed are treated with the required quantity of mercuric chlorid, preferably in solution. The solution is then heated, the reaction being effected most rapidly at boiling temperature.

The reactions may be expressed as follows:

(1) With ferrocyanid of potassium:

2K,FeCy+8HgCl2 = 6HgCy2+ FeCl + Hg2Cl2 + 8KCl. (2) With ferricyanid of potassium:

2K,FeCy. + 6HgCl2 = 6HgCy2 + FeCl + 6KC1.

(3) With Prussian blue:

2Fe,Cy18+ 24HgCl2 = 7FeCl + 18HgCy2 + 2Hg2Cl2.

If the materials used contain free acid, then the mercuric cyanid formed during the reaction is at once decomposed, yielding hydrocyanic acid.

FORMALDEHYDE SULPHOXYLATE AND PROCESS OF MAKING SAME.

Max Bazlen and Theodor Wohlfahrt, of Ludwigshafen-on-theRhine, Germany, assignors to Badische Anilin und Soda Fabrik. Patent No. 793,559, dated June 27, 1905.

The inventors have discovered that by allowing one molecular proportion of a hydrosulphite and one molecular proportion of formaldehyde to react on one another in the presence of caustic alkali or of an alkaline earth salts of formaldehyde sulphoxylic acid can be obtained easily and in good yield, and at the same time a normal sulphite is formed which does not combine with formaldehyde and can easily be removed from the aforesaid compound by any suitable method—such, for instance, as by evaporating the solution till the sulphite salt crystallizes out or by precipitation by the addition of alcohol. Instead of formaldehyde other equivalent aldehyde—such, for instance, as acetaldehyde or benzaldehyde may be employed and corresponding compounds be obtained. The salts of formaldehyde sulphoxylic acid thus obtained are claimed else

where; but what are claimed specifically are the new process for the manufacture of these bodies and the new specific sulphoxylic-namely, the monocalcium salt of formaldehyde sulphoxylic acid. This salt is easily soluble in water and reduces indigo carmine upon heating, which capacity is not increased by treatment with zinc-dust and acetic acid, it is difficultly soluble in absolute methyl alcohol and contains no formaldehyde bisulphite compound, and upon addition of a solution of sodium carbonate to its aqueous solution yields a white precipitate. Upon titration in neutral solution with iodin this compound requires more than three atomic proportions of iodin to each atomic proportion of sulphur present. When heated, it does not melt.

PROCESS OF MAKING DIAZO COMPOUNDS. Traugott Sandmeyer, of Basel, Switzerland, assignor to Aniline Color and Extract Works, formerly John R. Geigy. Patent No. 793,743, dated July 4, 1905.

This invention is based upon the discovery that sulpho-acids of the l-amido-2-naphthol can be transformed under certain conditions into the corresponding diazo compounds or sulfo-acids of the naphthalene-1-2-diazo oxid, (Bamberger, Ber., XXVII., 683,) which new diazo compounds are obtained in pure and dry state in the form of free sulphonic acids or their salts. Hitherto by diazotizing the aforesaid sulphonic acids of the 1-amido-2-naphthol in the usual manner-namely, in the presence of free mineral acids the nitrous acid reacts chiefly as oxidizing agent transforming the amidonaphthol sulphonic acids mostly into naphthoquinone sulphonic acids. It is now found that without an addition of a mineral acid, but only by mixture of a 1-amido-2-naphtholmono or polysulphonic acid or its acid salt with a solution of sodium nitrite, an easy and complete diazotation takes place if a proportionally small quantity of a neutral copper salt has been first added to the sulphuric acid or to the sodium nitrite. In a limited measure the same catalytic effects are also shown by other metallic salts, especially iron salts.

PROCESS OF MAKING INDIGO-WHITE.

Paul Seidel and Robert Wimmer, of Ludwigshafen-on-the-Rhine, Germany, assignors to Badische Anilin und Soda Fabrik. Patent No. 794,049, dated July 4, 1905.

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When manufacturing indigo according to the more important processes, indoxyi and indoxylic acid, hereinafter referred to as indoxylic bodies," are obtained as intermediate products, and these are oxidized to indigo. For use the indigo has to be reduced again to indigo-white. No process by which indoxylic bodies could be oxidized to indigo-white has hitherto been known, but it is now discovered that indoxylic bodies can be oxidized to indigo-white by using a quantity of oxidizing agent insufficient to oxidize the whole to indigo, and it is claimed that indigo is itself a suitable oxidizing agent for oxidizing indoxylic bodies to indigo-white, and at the same time it is itself reduced to indigowhite. For example, by blowing through a solution of an indoxylic body a quantity of air sufficient to oxidize the whole to indigo-white, but insufficient to oxidize it all to indigo, or when indigo is used as the oxidizing agent by acting upon a quantity of an indoxylic body with such a quantity of indigo, a solution containing practically only indigo-white results. It is not necessary to isolate the indoxyl and indoxylic acid before carrying out this reaction, as the alkaline melt obtained in the usual preparation of these compounds can be employed. By using a small quantity of certain bodies, which we call " oxygen-carriers -such as iron salts, alkali sulfites, &c.—the speed of this reaction is increased. The alkali solution of indigo-white which results in either of the foregoing cases can be filtered from any indigo which is present and can be further treated as desired.

PROCESS OF CHEMICALLY MODIFYING OILS. Eduard Meusel, of Liegnitz, Germany. Patent No. 794,373, dated July 11, 1905.

The present invention has for its object the industrial appli

cation of denitrificating bacteria for breaking up the nitrogenous substances to permit of the oxygen therein contained uniting with the fatty oils to change their chemical constitution, whereby modified oils are produced suitable for many varied uses in the industrial arts due to the peculiar qualities imparted thereto by this chemical change.

In this process a culture of denitrificating bacteria-such as, for instance, cheese bacteria-is mixed with one kilogram of a fatty oil and two liters of a five-per-cent. solution of nitre, with addition of suitable nutritive salts, the mixture being thoroughly shaken for the purpose of effecting a good airing. It is expedient to add chips of wood in order to accomplish as thorough a mingling as practicable of the oil with the solution of salt and the dentifricating bacteria and to effect an energetic airing. The reaction takes place in the best and quickest manner at about 30° centigrade. According to the kind of denitrificating bacteria and oils the reaction takes a longer or shorter time. After the modified oil produced has been freed from the aqueous solution containing glycerin it possesses a more or less modified consistency, the acid number is very high, and the iodin number is often greatly changed. The products obtained in this manner are easily soluble in a dilute solution of soda.

The modified oils are excellently adapted for the manufacture of degras, lacquers, mordants for dyes, and like substances.

PROCESS OF MAKING ALUMINIUM COMPOUNDS. Lucius Richard Keogh, of Hamilton, Canada. Patent No. 794,413, dated July 11, 1905.

The object of the invention is to provide a new and improved method of making, as products, aluminum compounds and byproducts, such as aluminum sulphate, aluminate of soda, anhydrous alumina, hydrated alumina, sodium sulphate, sodium sulphide, sodium carbonate, hydrochloric acid, sulphureted hydrogen, sulphur dioxid, sulphur trioxid, sulphuric acid, sulphur, sulphide of iron, sulphate of iron, and other substances that may