Abstract: In a process of producing coarse pure potassium chloride crystals from feed solutions containing potassium chloride and other impurities, comprising cooling the solution under a vacuum in a plurality of stages connected in series, withdrawing by means of a conveyor the potassium chloride which has been crystallized in each stage, withdrawing the water vapors, collecting crystalline potassium chloride from the solution, drying the crystalline potassium chloride and separating the same into several fractions, compacting the fine fraction and cooling and aminating the end product, the potassium chloride content of the feed solution is increased in that potassium chloride from one or more of the stages containing solution at a low temperature is recycled to the feed solution before the latter enters the first stage.

Abstract: Formic acid is recovered, by distillation, from its mixtures with solvents of the general formula I ##STR1## where R.sup.1 is hydrogen, methyl, ethyl or vinyl and R.sup.2 and R.sup.3 are each alkyl, cycloalkyl, aryl or aralkyl, or R.sup.2 and R.sup.3 together form a 1,4- or 1,5-alkylene group, in each case of not more than 8 carbon atoms, with the provisos that the sum of the number of carbon atoms in R.sup.2 and R.sup.3 is 7 to 14 and that only one of these radicals is aryl, by a method in which the distillation is carried out in the presence of a carboxamide II which is selected from the group consisting of formamide, acetamide, propionamide and the same compounds substituted by N-methyl or N,N-dimethyl, and which has a boiling point lower than that of the solvent I.

Abstract: Finely divided, pulverulent carotinoid or retinoid compositions, in which the carotinoid or retinoid essentially has a particle size of less than 0.5 micron, are prepared by a process wherein a carotinoid or retinoid is dissolved in a volatile, water-miscible, organic solvent at from 50.degree. C. to 200.degree. C., if necessary under superatmospheric pressure, within the space of less than 10 seconds. The carotinoid is immediately precipitated, in a colloidally disperse form, from the molecularly disperse solution by rapidly mixing the latter with an aqueous solution of a swellable colloid at from 0.degree. C. to 50.degree. C., and the resulting dispersion is freed from the solvent and the dispersing medium in a conventional manner.

Abstract: The present invention is directed to novel amino-substituted 2-cumaryl-3'-chromenylium salts of the general formula ##STR1## wherein R.sup.3 and R.sup.7 are a dialkyl or cycloalkyl disubstituted amino group, hydrogen, or hydroxy group, provided that at least one of R.sup.3 and R.sup.7 is an amino group, R.sup.1, R.sup.2, R.sup.4, R.sup.5, R.sup.6, and R.sup.8 are hydrogen, an alkoxy group, or two of these substituents together form an aromatic ring, provided that R.sup.1, R.sup.2 and R.sup.4 may be the same or different, and R.sup.5, R.sup.6 and R.sup.8 may be the same or different, and Y.sup.- is an acidic anion and to the process for their preparation.

Abstract: It is the purpose and object of the present invention to make better use of the emission range of light sources and to create the diazonium salts necessary for such purpose. The diazonium salts of the present invention of the general formula ##STR1## wherein Y is ##STR2## R.sub.1, R.sub.2 are equal or different and are, alkyl having 1 to 10 carbon atoms, aryl having 6 to 10 carbon atoms in a mono or polycylic ring;R.sub.3 is hydrogen, halogen, alkyl, alkoxy, cyano;R.sub.4 is hydrogen, halogen, alkyl, alkoxy; andX.sup.e is an anion,can be employed with all known couplers and additives in diazotype materials. They have an absorption range of 480 to 550 nm.

Abstract: A process for separating off organic iodine compounds from acetaldehyde-free carbonylation products of methanol, methyl acetate and dimethyl ether by removing the iodine compounds by azeotropic distillation with a hydrocarbon having a boiling point, under atmospheric pressure, of 25-55.degree. C.

Abstract: A process is provided wherein acetaldehyde and methanol are obtained from reaction mixtures which result from the homologization of methanol and which in addition to acetaldehyde essentially contain acetaldehyde dimethylacetal, methanol, methyl acetate and water.

Abstract: Liquid mixtures containing aliphatic alcohols are separated, by distillation, into a higher-boiling alcohol-containing fraction and a lower-boiling fraction containing the other liquids, by carrying out the fractionation in the presence of water and of an alkanal and, over about 3/4 of the column height, in the presence of a non-volatile or only slightly volatile acid.

Abstract: A process for separating off organic iodine compounds from acetaldehyde by subjecting the acetaldehyde to azeotropic distillation with a hydrocarbon boiling at from 25.degree. to 55.degree. C. under atmospheric pressure.

Abstract: A cutting device for foodstuffs in which a container is provided with a cutter carried at the end of a spring biased plunger. The plunger is carried in a guide, formed separately of the container, as a member of a bell-shaped two part foldable housing, which is adapted to seat on the container. The plane of division of the two part housing being in the direction of movement of the cutter members.

Abstract: A cutting device for foods, in which a bowl having a rotatable central shaft is provided with a cover in which a plunger is secured. At the end of the plunger a head having a plurality of knives is located. The plunger and the cover are arranged to enable axial movement of the plunger without rotation of the head, while the knife head and the rotatable shaft are engaged. The latter two are arranged to enable both axial and rotatable movement of the head on the shaft when depressed by the plunger.

Abstract: Method and apparatus for automatically focusing an optical system, particularly a microscope. A grating is located in the intermediate image plane and acts as a spatial frequency filter. A photoelectric detection system is associated with the grating. Electrical control signals are generated which are modulated by the relative motion between the object image and the grating. This motion is preferably normal to the longitudinal range of the grating marks. The grating used is short compared to the range of the intermediate image. The relative motions extending across several grating constants are generated between the image and the grating.