WILLIAM S. HILL Melnber, Examining Corps, United States Patent Office Method of Protecting Tubers against Decay. No. 2,348,946. Margaret Wilson, Raleigh, North Carolina. Microorganisms generally present in the soil affect potatoes and other tubers grown in many sections of the country. Some of these cause unsightly discolorations of the skin of the tubers, thus reducing their sale value greatly. Some examples of the troublemakers are rust, rhizoctonia, and scurf. The patent describes treatment of the tubers with a 2 to 6 per cent solution of sodium hypochlorite .which has been found to dissolve the organisms readily, as they are largely composed of lignin. Dipping in the weak solution or spraying and brushing have been found effective. The treatment is completed by washing the tubers in a dilute solution of ammonium hy.droxide. Method of Producing Protein Plastics by Cold Molding. No. 2,348,761. Oswald C. H. Sturken, Closter, New Jersey. Casein plastics are commonly made from the protein of zein, soy bean meal, casein, blood albumin, or ground horn. Large numbers of articles such as belt buckles and buttons are made from this type of raw material. One example of the process is to start with powdered zein of 60 to 120 mesh. The powder is mixed with about 10 per cent of its weight of water, sifted, and placed in a cold mold. The mold is subjected to a pressure of 1500 to 15,000 Ibs. per square inch. Casein plastics are hardened by treating with formaldehyde. This treatment is improved in the present patent by using a mixture of formaldehyde and kieselguhr (diatomaceous earth). The articles are submerged in the mixture which is agitated to prevent settling of the kieselguhr. After about 30 minutes' treatment the surfaces of the casein articles have become tacky from the action of formaldehyde, but the kieselguhr forms a coating on the surfaces which prevents sticking. The articles are then removed and may be further treated in 40 per cent aqueous formaldehyde alone. A belt buckle only '/, inch thick requires about 4 to 5 days' treatment in order to become homogeneous. The articles are removed from the bath, dried out thoroughly, and may then be further hardened by baking at lOO°C. The fine coating of kieselguhr may be left on the articles or. if undesirable for some uses, may be washed off with sodium hypochlorite.
from which to manufacture implants for use in mounting artificial teeth. At one time it was common dental practice to mount metal crowns on the natural roots of teeth whose cusps had been removed. This practice has been largely discontinued. Later it was suggested that artificial teeth be mounted on a specially constructed metal frame inserted in the alveolus of an extracted tooth or in a cavity drilled in the jawbone. The difficulty was to find a metal or alloy that produced no objectional effects such as electrolytic action with the mouth tissue fluids. A suitable alloy sold for this purpose is composed of 65 cobalt, 30 chromium, and 5 per cent molybdenum. The present invention is the substitution of a nonmetallic material which will not only be free of harmful chemical action but which can be incorporated with a germicidal substance that inhibits infection. The substance used is methyl methacrylate resin and the germicidal chemicals mixed with it may be silver nitrate, iodine crystals, sulfa derivatives, etc. When the dental implant is in place its porous nature causes it to give up its germicidal component slowly, thus keeping the surrounding tissue healthy.
Ultraviolet-Sensitive Photographic Element. No. 2,349.760. Earle E. Richardson, et al., assignors to Eastman Kodak Company. Spectrophotography plays a considerable part in modenl industrial and scientific research. In this field the characteristics of various materials under the influence of ultraviolet radiations are of interest. Much of this kind of work is done with the quartz spectrograph using commercially obtainable photographic plates or films. However, the gelatin emulsions absorb radiations of very short wave lengths and this prevents their action on the embedded silver halide grains. Previously, attempts have been made to overcome this drawback in at least two ways. One was to incorporate fluorescent substances in the emulsion. These substances transformed the shorter wave lengths into wave lengths not strongly absorbed by the gelatin. The second was to overcoat the emulsion with a thin film of ethyl-dihydro-collidine-dicarboxylate in order to bring about the necessary energy transformation. But the use of this overcoating substance necessitates an extra wash with alcohol while the element is in the developer. The present patent presents an ultraviolet sensitizing layer completely removed in the regular alkaline deDental Implant. No. 2,347,567. Edward J. Kresse, velopers and requiring no additional treatment. The Denver, Colorado. materials found effective are bis-ammonium salts of This patent relates to improvements in materials aliphatic amines selected from the group consisting of 461
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dialkyl and trialkyl amines in which each alkyl group contains from 7 to 12 carbon atoms, and a bis-sulfonic acid of the general formula. H?rYl-
