Document OEbdypyD2jkmM0aM4N8aq70jM

1J52 Ceramic Abstracts Vol. 20, No. 5 operations tar a few days; the danger was reduced by thu alternation. If the workshop develops into a factory, however, one group of workers is continually kept at glasing operations; the exposure to the lead hazard is thus A similar effect was seen in the fetus. Beryllium and its salts arc made in Italian factories, and the beryllium car bonate used in the experiments came froth two factories. That from one source was noticeably more toxic than that continuous, and the danger is very great. In England in from the other. Illustrated by roentgenograms and photo 1900 the danger in the pottery industry was at iisjnaxi- micrographs. F.S.M. mura. 210 cases being reported in that year. In 193J only Response of peritoneal tissue to industrial dusts. J. W. 5 cases were reported. Mills* and R. R. Savksv U. S. Pah. Health Repis., 36 Noise and vibration control. G. H. Fkbuson. Cos. |7| 264-72 (1941).--Several previous reports upon the re Pub. Health Jour.. 31, 613-18 (Dec.. 1940).--F. discusses action of peritoneal tissue to injected dusts are referred to. noise and vibration in industry, their effects on health, and Such biological response is produced for the purpose of various methods of control. Legislation and the cxtcnuoc predicting the pneumoconiosis-producing potentialities of of to include dimes comtd by noise ate industrial dust. The experimental procedure upon guinea believed to be efficient ways of eliminating avoidable in pigs as now practiced is given briefly. No cases of pneu dustrial noises. Workers should be carefully selected in moconiosis have been reported and confirmed among cases where is unavoidable. The protection of hear workers exposed solely to dusts of the absorptive group; ing by the application of prophylactic measures, rest all the dusts in the proliferative group, however, are known pauses, etc., is discussed. F.S.M. to produce a nodular, pulmonary fibrosis (silicosis). Pneu Progress in ceramics shirs 1926, W. Funk, Aagrw. moconioses caused by dusts of the inert group (asbestos, Chem., S3 121-22) 221-27 (1940).--Clay research in the anthracite mine, bisque ware. mica, pyrophyllite, and talc last decade has developed accurate methods of determin dust) have been reported, following X-ray examinations at ing particle sizes of clays that trill allow systematic clssn- , industrial workers. The interpretation at the response at a fication of clay types. The chief clay minerals are dust injected into the peritoneal tissue of animals can be kaoiinite. AhOi-2SiOi-2HiO. and montmorillooite. used as an index to determine the potential hnrmfulness of AW0i-4SiOi'HjO.atHiO, with air-dry moounorilloniie (m) an industrial dust. Ten industrial dusts causing an absorp lying between 4 and 5. Valuable results have been ob tive reaction examined by this method are listed, together tained in regard to the adsorptive properties of clays and with Iheir chemical composition and other pertinent identi base exchange. American research work on pH values and fying data. Among the more familiar substances in this on NajCOi as a mrans of '~K"rnf the pH has resulted in list are calritr. gypsum, various limestones, and Portland greater density and higher fired strength of ceramic goods. cement. Thirteen dusts causing a proliferative reaction, Bentonite in ceramic masses has been found to be a suit among which are five kinds of quartz, quartz-sericitc, and able substitute far highly plastic days. The castability of tripoii. were also examined. Of this group, those at special day slips is favorably influenced by alkali-soluble humic ceramic interest include (1) bisque ware, a ground wmi- substances. In clay preparation, improvements have been vitrrous pottery bisque fired at a relatively low tempera achieved with regard to the magnetic separation of iron ture, which shows oo chemical analysis 72% silica and an particles by means of rapidly vibrating fine-mesh screens. petrographic examination 46 to 50% quartz, the remainder In Germany, filter doth has latdy been replaced by a new being semifused clay and feldspv: (2) green ware, a ground type of filter tile, the filtration speed of which is taro to sem.vitreous pottery ware, which shows on chemical ex three times higher than that of doth. The deairing of amination 60% silica and on petrographic examination day masses, originally applied to heavy-day products about 56% quartz, about 15% feldspar, and about 35% only, is now being applied to fine ceramic ware. Much clay; another sample of greenware showed higher quartz study has been devoted to the firing process, i.c.. firing and len feldspar and cby in altout the same amount; (3) temperatures, firing period, and kiln atmosphere; the porcelain enamel frit which shows on chemical analysis ratio of the vitrifying and crystal substance to the volume 35 to 56% silica, the remainder being oxides of antimony, of the pares determines the properties of the goods. Re zinc, aluminum, and calcium. Twenty-seven dusts caus sults of tests show the possibility of firing chinaware and ing an inert reaction include aluminum, three types at steatite at lower temperatures without increasing the firing asbestos, two type* of anthracite coni, two types at bitu period over a certain limit. Electrically heated kilns have minous coal, calcium phosphate, chromite, diamond dust, been used in the ceramic industry since 1934; their ad feldspar, four iy|>cs of fuller's earth, hematite, vantage lies in the fact that the firing process can be regu kaolin, mica, scricite. taro soapMinlft^BCT and talc. lated at will. The high-frequency technique uses dielec Another bisque ware in the group, tired at a relatively high tric masses containing titanium dioxide for insulators an A temperature, has altout 30 to 40% quartz; the particles condensers; formerly steatite was used exclusively. In are wholly or partly covered by the glass phase, absent in the refractory industry, important developments have bee t the semivitreous; kaolin of this group shows, petrographi- achieved in the fidd of special high-quality refractories. cally. predominantly china clay and hydromica, with traces Magnesite brick resisting thermal shock ?.re manufactured only of quartz and feldspar. See "Relative . . Ceram. without loss of other properties. Zircon refractories aie Abs.. 20 |21 59 (1941). K.R. widely used for furnace linings. Sillimanite, silicon car Significance of chemical findings in the pathology of bide, and corundum are used where resistance to extreme mineral pneumoconioses. A. Poucard. Arch. Malad. temperatures is required. An extensive bibliography is Profess.. 1 |6 ) 473-88 (1938).--With dust increases, calci included. ' . F.E.S. fied parts have also increased, but the silica percentages Pumping of granular solids in fluid suspension. Hbr- fall proportionately. In tubercular lungs there is s high BKXT Chatlsy. En[ineenn[, 149, 230-31 (1940).--The dust content but a low silica content. Unfortunately, low efficiency usually obtained is attributed largely to chemical findings show only total silica and not the re bends and inlets or to the incorrect proportioning of fluid spective totals of free silica and that occurring as silicates. and solid. When solids are not sustained in the stream, Free silica is highly toxic, while the silicates are relatively they can be propelled horizontally only by rolling, requir ing a much greater expenditure of energy. B.C.R. Rachitogenic effect of beryllium carbonate. L. Businco. Rats. Med. Appiicata Lavoro, 11, 417--12 (1940).--Doses of beryllium carbonate varying from 0.1 SO to 0.037 gm. innocuous. It is desirable to know the quantity of free silica, whether it exists as quartz or chalcedony. No rela tion has been established between the amount of fibrosis and the amount of silica present in the lungs of silicotic*. The lungs of nonsilicotics may have as much or more silica were given daily to rats for periods up to 48 days. The than lungs freely conceded to be silicotic. The length of animals lost weight and were less active, and changes in the time the worker has spent in the dust seems to be more vertebra, ribs, and the epiphyses of the tibia and femur important than his ascertained lesions. P. emphasizes the were observed by means of the roentgenograph: Histo logical examination showed typical rachitic changes in many epiphyses; these were not improved by the adminis tration of cod-liver oil and other antirachitic substances. vagueness and the mere approximation of such findings in a pathogenic study toward ascertaining the mechanisms of the pneumoconioses. Regional analyses of parts of lungs exposed to dusts have also little actual value. Chemical PLAINTIFFS EXHIBIT SA-386a 01 501 0005