A stable composition for hair treatment contains (1) 1-5% by weight of an organosilane, its hydrolysis product or its polymerization product in a dissolved state in an aqueous medium, the silane originally containing at least one organic group attached directly to the silicon atom and 1-3 hydrolyzable groups or atoms attached directly to the silicon atom, and (2) a base to adjust the pH of the composition to 5-10.  The silane may have the formula <FORM:0880926/IV (a)/1> in which X is chlorine, bromine, methoxy or ethoxy and R is hydrogen, an alkyl group, e.g. methyl, ethyl, propyl, butyl or isobutyl, or an aryl, aralkyl or alkaryl group, e.g. benzyl, phenyl, tolyl, styryl or naphthyl, at least one of the R groups being an organic group which may contain less than 8 carbon atoms in straight or branched chain arrangement and an unsaturated carbon to carbon linkage through which addition polymerization may take place, e.g. alkyl, vinyl, and methallyl.  The base may be ammonia, a weak acid salt, e.g. sodium acetate or formate, or an alkali metal hydroxide and the composition, which is preferably prepared at a temperature below 80 DEG  F., may also contain lubricants, e.g. organo-silica fluids in aqueous dispersion such as dimethyl polysiloxane and diethyl polysiloxxane, mineral oils, palm oil, olive oil and other vegetable oils, fatty acids and fatty acid amides, and 0,05-2% by weight of a surface-active agent, e.g. aryl alkyl polyethylene glycol ethers, sorbitan monolaurate, monopalmitate or monostearate polyoxyethylene derivatives, the dioctyl ester of sodium sulpho succinate, alkyl naphthalene sulphonates, sorbitan sulpholeates, fatty alcohol sulphates and aromatic polyglycol ethers. The hair is treated with the composition and the diluent eliminated, e.g. by slow evaporation or by the use of a hot comb, heat lamp or curling iron, polymerization of the organosilicon compound occurring during the elimination of the diluent or subsequent thereto so that the hair is held in the desired configuration.  The composition may contain a mixture of silanes, it being desirable to balance the silanes with respect to the number of hydrolyzable groups or atoms to control the polymer structure between liquid polymers of low moledular weight and harder polymers of high molecular weight and also to provide for a balance between silanes of long chain fatty acid groups, e.g. dioctadecyldiethoxy silane, which forms soft and flexible lubricating polymers, and silanes of short chained organic radicals, e.g. methyl and ethyl groups, and phenyl groups which produce harder solids of resinous nature. Specifications 675,188, 729,452, 751,992 and 753,241 are referred to.ALSO:A stable composition used for straightening kinky hair or for curling hair contains (1) 1%-5% by weight of an organo silane, its hydrolysis product or its polymerization product in a dissolved state in an aqueous medium, the silane originally containing at least one organic group attached directly to the silicon atom and 1-3 hydrolyzable groups or atoms attached directly to the silicon atom, and (2) a base to adjust the pH of the composition to 5-10.  The silane may have the formula <FORM:0880926/IV (c)/1> in which X is chlorine, bromine, methoxy or ethoxy and R is hydrogen, an alkyl group, e.g. methyl, ethyl, propyl, butyl or isobutyl, or an aryl, aralkyl or alkaryl group, e.g. benzyl, phenyl, tolyl, styryl or naphthyl, at least one of the R groups being an organic group which may contain less than 8 carbon atoms in straight or branched chain arrangement and an unsaturated carbon to carbon linkage through which addition polymerization may take place, e.g. allyl, vinyl and methallyl.  The base may be ammonia, a weak acid salt, e.g. sodium acetate or formate, or an alkali-metal hydroxide and the composition, which is preferably prepared at a temperature below 80 DEG F., may also contain lubricants, e.g. organo-silicon fluids in aqueous dispersion such as dimethyl polysiloxane and diethylpolysiloxane, mineral oils, palm oil, olive oil and other vegetable oils, fatty acids and fatty acid amides, and 0.05%-2% by weight of a surface active agent, e.g. aryl alkyl polyethylene glycol esters, sorbitan monolaurate, monopalmitate or monostearate polyoxyethylene derivatives, the dioctyl ester of sodium sulphosuccinate, alkyl naphthalene sulphonates, sorbitan sulphooleates, fatty alcohol sulphates and aromatic polyglycol ethers.  The hair is preferably washed and is then treated with the composition and the dilutent eliminated, e.g. by slow evaporation or by the use of a hot comb, heat lamp or curling iron, polymerization of the organo silicon compound occurring during the elimination of the diluent or subsequent thereto so that the hair is held in the desired configuration.  In permanently waving hair, the hair may be arranged in the desired configuration on curlers before applying the composition, and in hair-straightening the hair is preferably combed or brushed straight during the final stages of the elimination of the diluent.  Kinky hair which has been straightened by the process may subsequently be permanently waved by wrapping the hair about curlers and heating, with or without the application of additional treating composition or by using thioglycolic acid and subsequently oxidising.  The composition may contain a mixture of silanes, it being desirable to balance the silanes with respect to the number of hydrolyzable groups or atoms to control the polymer structure between liquid polymers of low molecular weight and harder polymers of high molecular weight and also to provide for a balance between silanes of long-chain fatty acid groups, e.g. dioctadecyl diethoxy silane, which form soft and flexible lubricating polymers, and silanes of short-chained organic radicals, e.g. methyl and ethyl groups, and phenyl groups, which produce harder solids of resinous nature.  Compositions containing organo silicon compounds in the form of a silane or a corresponding silanol containing an aryl group attached directly to a silicon atom are stable against immediate condensation reaction to form the polymer while in aqueous medium and after application the hair may be dried, arranged in the desired configuration and then heated to effect polymerization and setting.  Specifications 675,188, 729,452, 751,992 and 753,241 are referred to.