Acyclic methylene ethers of partially alkylated or aralkylated polyhydric alcohols are prepared by reacting said partially alkylated or aralkylated alcohols with formaldehyde or its equivalent. For example, formaldehyde is reacted with the mono-methyl ether of ethylene glycol in the presence of an acidic condensing agent, e.g. ferric chloride, hydrochloric acid, sulphuric acid, or phosphoric acid. Other partial ethers which may be employed are the mono-ethyl ether of ethylene glycol and the mono - methyl and mono - ethyl ethers of propylene glycol. The products may be employed to dissolve or soften cellulose derivatives in the manufacture of dopes, film-forming solutions, plastics, coating and insulating compositions. They may be employed in conjunction with other known solvents and/or diluents, a number of which are specified. The Specification as open to inspection under Sect. 91 relates generally to a process for making ethers by reacting partial ethers of polyhydric alcohols with aldehydes or ketones. Partial ethers specified are mono-methyl and monoethyl ethers of ethylene glycol, propylene glycol, or di-ethylene glycol. Suitable aldehydes or ketones are formaldehyde, trioxymethylene, para-formaldehyde, acetaldehyde, benzaldehyde, acetone, and cyclohexanone. The ethers may be used as solvents or softeners for cellulose esters, natural or artificial resins, and as solvents for dyestuffs. Of particular importance is their application in the manufacture of artificial silk, films, sheets, dopes, varnishes, plastics, and the like, containing cellulose esters. For example, they may be employed in wet spinning processes, in the coagulating bath as is described in Specifications 179,234, [Class 2 (ii)], 340,324, and 340,325, and in subsequent treatment baths as in Specification 340,437. The ethers may also be employed in the treatment of artificial filaments, films, fabrics, and the like, to reduce the tendency to slip, split, or ladder, as in Specification 280,990, [Class 42 (i)]; to improve the pliability by shrinking, as described in Specification 389,823, and to improve tenacity by stretching according to the precesses of Specifications 277,089, 323,790, [both in Class 2 (ii)], 370,430 and 371,461. The ethers may also be used in the preparation of sizes for textiles. Filaments, films, fabrics, and the like may be treated with the ethers to facilitate absorption by the materials of substances adapted to dye, print, load, mordant, and delustre the materials. A further application of the ethers is to relustre, uniformly or locally, fabrics which have been delustred by the action of moist steam or of hot aqueous media according to the process of Specification 259,265, [Class 2 (ii)]. Examples are given of coating compositions containing (1) cellulose acetate, diphenylol propane formaldehyde resin, dibutyl tartrate, tricresyl phosphate, the condensation product of mono-methyl ether of ethylene glycol and acetone, diacetone alcohol, acetone, and dioxane; (2) cellulose acetate, polyvinyl acetate, dibutyl tartrate, the condensation product of mono-methyl ether of ethylene glycol and acetaldehyde, acetone, alcohol, and benzene; (3) polymerized vinyl acetate, diphenylol propane formaldehyde resin, tricresyl phosphate, the condensation product of mono-methyl ether of propylene glycol and formaldehyde, alcohol, and dioxane; (4) a plastic mass is made by incorporating cellulose acetate with tricresyl phosphate, monomethylated isomeric xylene sulphonamides, benzene, alcohol, and the condensation product of formaldehyde with mono-methyl ether of propylene glycol, while allowing the solvent to evaporate; (5) a solution of cellulose acetate in a solvent mixture containing acetone and the condensation product of formaldehyde and the mono-ethyl ether of ethylene glycol is extruded through orifices into a coagulating bath consisting of an aqueous solution of diacetone alcohol; (6) a solution of cellulose acetate in acetone and the condensation product of formaldehyde and mono-methyl ether of ethylene glycol is spun into an evaporative atmosphere. Specification 380,504 also is referred to. This subject-matter does not appear in the Specification as accepted.ALSO:Acyclic methylene ethers of partially alkylated or aralkylated polyhydric alcohols are prepared by reacting said partially alkylated or aralkylated alcohols with formaldehyde or its equivalent. Examples of partial ethers which may be employed are the mono-methyl and mono-ethyl ethers of ethylene glycol and propylene glycol. The products may be employed to dissolve or soften cellulose derivatives and may be used in conjunction with other solvents and/or diluents, a number of which are specified. The Specification as open to inspection under Sect. 91 relates also to processes for making ethers by reacting partial ethers of polyhydric alcohols with aldehydes or ketones. Partial ethers specified are mono-methyl and mono-ethyl ethers of ethylene glycol, propylene glycol, or di-ethylene glycol. Suitable aldehydes or ketones are formaldehyde, trioxymethylene, paraformaldehyde, acetaldehyde, benzaldehyde, acetone, and cyclohexanone. The ethers may be employed as solvents or softeners for cellulose derivatives and/or natural or artificial resins. Examples are given of coating compositions containing essentially cellulose acetate and the condensation product of mono-methyl ether of ethylene glycol and acetone; cellulose acetate and the condensation product of mono-methyl ether of ethylene glycol and acetaldehyde; and polymerized vinyl acetate and the condensation product of mono-methyl ether of propylene glycol and formaldehyde. This subject-matter does not appear in the Specification as accepted.ALSO:Acyclic methylene ethers of partially alkylated or aralkylated polyhydric alcohols are prepared by reacting said partially alkylated or aralkylated alcohols with formaldehyde or its equivalent. Examples of partial ethers which may be employed are the monomethyl and mono-ethyl ethers of ethylene glycol and propylene glycol. The products may be employed to dissolve or soften cellulose derivatives and may be used in conjunction with other solvents and/or diluents, a number of which are specified. The Specification as open to inspection under Sect. 91 relates also to processes for making ethers by reacting partial ethers of polyhydric alcohols with aldehydes or ketones. Partial ethers specified are mono-methyl and mono-ethyl ethers of ethylene glycol, propylene glycol, and di-ethylene glycol. Suitable aldehydes or ketones are formaldehyde, trioxymethylene, para-formaldehyde, acetaldehyde, benzaldehyde, acetone, and cyclohexanone. The ethers may be employed as solvents or softeners for cellulose derivatives and/or natural or artificial resins, and also in the preparation of sizes for textiles. An example is given of a plastic composition obtained by working up cellulose acetate with tricresyl phosphate, mono-methylated isomeric xylene sulphonamides, benzene, alcohol, and the condensation product of formaldehyde with mono-methyl ether of propylene glycol. This subject-matter does not appear in the Specification as accepted.