Abstract: A protein-vitamin concentrate having a high proportion of dry yeast and a protein content of at least 50% and particularly rich in B-vitamins, is produced by cultivating yeast in a culture medium containing animal or vegetable fat as a source of carbon, at a pH of 4 to 6 and a temperature of 30.degree. to 40.degree.C. and an aeration intensity of 150 to 300 cubic meters of air per square meter of fermenter base area per hour, the culture containing also an ammonium salt or carbamide as a source of nitrogen, the nitrogen content of the culture medium being 0.1-0.2%, the N:P ratio being 4:1, potassium and chloride ions being present in the form of 0.1-0.2% KCl, and Mg and SO.sub.4 ions being present as 0.080-0.1% MgSO.sub.4.

Abstract: A component of a gaseous mixture, particularly carbon dioxide, can be measured in extremely small quantities or concentrations, by supporting on a solid surface a thin film of a liquid, e.g. an aqueous solution of barium hydroxide, which reacts with the gaseous component so as substantially to alter the electrical resistance of the solution. The electric resistance of the film is measured between electrodes, before and after exposure to the test gas. The test is much more sensitive than if a confined body of liquid were used as the test solution.

Abstract: Peptisable natural aluminum hydrosilicate organo complexes are separated from water-insoluble organic and/or inorganic mineral materials and from natural aluminum hydrosilicate organo complexes that cannot be peptised in water, by milling mineral materials such as clay or brown coal to a size smaller than 60 microns, vigorously mechanically agitating the mixture at 60 to 120.degree. C. so as to dissociate the same to the colloidal state, during which the hydrophilic binding positions of the material are loosened by hydration, and finally separating the thus-formed peptised solution from insoluble material. The solution may be concentrated and the insoluble material itself is useful because of increased calorific value and higher specific surface area. Peptisation may be carried out in the presence of peptising agents such as ammonia-soda, Na.sub.2 CO.sub.3, NaOH, KOH, or cetyl-pyridine-chloride, in an amount up to 5% by weight.

Abstract: Soil conditioning compositions in which the active component is a reactive tenside being (a) condensation products, having a molecular weight under 15,000, of one or more of (i) ethylenediamine, diethylenetriamine, propylenediamine, dipropylenediamine, guanidine, dicyandiamide, N-aminoethyl alkylamines, N-aminoethyl alkyleneamines, N-aminoethyl alkyldienamines, N-aminopropyl alkylamines, N-aminopropyl alkyleneamines, N-aminopropyl alk-dien-ylamines, imidazoline, imidazole, 1-aminoethyl-imidazoline, 1-aminoethyl-2-alkyl-2-imidazoline, and 1-aminoethyl-2-alkyl-2-imidazoline, and 1-aminoethyl-2-alkylene-2-imidazoline, with one or more of (ii) formaldehyde, acetaldehyde, propionaldehyde, C.sub.2-6 dihalogenealkanes; (b) alkyl- or alkylcarboxyamide end group-containing derivatives of reactions between the components of (a) which are partially or totally alkylated with C.sub.