Abstract: A single crystal of pure or mixed univalent mercury halide, which is formed having a pair of opposed polished faces at least one of which is perpendicular to a direction which is inclined from the optical axis of the crystal about the crystallographic direction by an angle between 0.2.degree. to 20.0.degree.. Another face of the crystal is provided with a source of transverse acoustic waves.

Abstract: Soluble, hydrophilic polymers suitable for medical use and as blood plasma substitutes comprising low molecular weight polymer derived from at least one monomer of an acrylamide type material or a mono-ester of an acrylic type acid and a glycol which is condensed with bifunctional compounds to form a condensation polymer having increased molecular weight and enzymatically cleavable cross-links. The hydrophilic polymer is produced by polymerizing the acrylamide type material or monoester mentioned above to form a low molecular weight polymer which is then condensed with a bifunctional compound to form a high molecular weight condensation polymer having enzymatically cleavable cross-links.

Abstract: A composition of matter with improved mechanical properties which contain 2 - 50 mol. percent of methacrylonitrile or acrylonitrile and 50 - 98 mol. percent of glycol monoesters of acrylic or methacrylic acid, where the glycol is selected from the group comprising ethylene glycol, diethylene glycol, triethylene glycol and their mixtures. 0.1 - 30 mol. percent of the glycol monoesters may be substituted by a crosslinking agent selected from the group comprising 1,4-cyclohexanedimethyl dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexamethylene-bis-acrylamide, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, methylene-bis-acrylamide, ethylene-bis-acrylamide. Also hydrogen catalysts of compositions bonded to platinum, palladium or rhodium metal.A process for producing the matter, wherein glycol esters of acrylic or methacrylic acid are copolymerized with methacrylonitrile or acrylonitrile, if desired in the presence of a crosslinking agent.