Document jgGMDb17aeB63zdY4VvVJDxMp

The American Ceramic Society . February 15,1993 I hereby certify that the attached copies of Ceramic Abstracts, Volume 18, 1939, are true and accurate copies, which are maintained in the normal course of business at the American Ceramic Society, 735 Ceramic Place, Westerville, Ohio 43081. /t>-_ Christine Schnitzer Product Manager Ceramic Information Center 735 Ceramic Place Westerville, Ohio 43081-8720 514 890 4700 TWX: 7101109409 XT- CERAMIC ABSTRACTS Compiled by The'`American Ceramic Volume 18,1939 Rosa C. Pubdy, Editor Maxy J. Gibb }Ewly C. Van Schoicx Doxothy J. Wallace Assistants CommitU* on Publications: J. D. SOLUvan. Chairman, W. W. WntSHIF, A. N. FINN. E. E. Mauaexx, R. C. PoitDY Abrtr*ct*f: T- B- Austin, A. A. Ayars. XTR. "Barrett. "KL'W. W. Bartlett, A. C. "Bevan. D. A. Biddle, W. H. Bruckner, P. Budnikov, J. C. Chaston, L. M. Church, W. M. Cohn, M. V. Coodoide. P. S. Dear, Maurice Delantre, R. W. Devillers, Joseph Ford, W. D. Foster, V. D. Frechette, J. L. Gallup, J. D. Gat, R. A. Grtfory. Max Hartenheim, J. J. Hazel. F. G. Heck, R. A. Heindl, P. G. Herald, G. M. Kutt, J. F. Hyde. Herbert tnsley, C. B. Jenni, B. Z. Karaich, B. E. Kinkulkin, S. Hondo, Yosio Hon, Waltber Kurz, B. B. Lane. V. S. de Marchi, L. F. May, E. H. McClelland. J. M, Noy, J. G. Phillips, Alexis Pincus, M, E. Poor. C. H. Rapp, Katherine Reed, H. K. Richardson, B. C. Ruprecbt, A. B. Searle. Stanford SetcheU, G. R. Shelton. N. M. Shukri, H. E. Simpson. A. P. Sotn, E. Stefanowski, E. W. Stenzel, A. G. Stern, Joseph Stewart, B. H. Strom, Ll E- Thiers, Hans Thurnauer, F. V. Tooley, E. J. Vachuska, F. E. Vaerewyck, F. J. Zvanut. Editorial Of&ct: 2525 North Hi*h Street, Columbus. Ohio Publication Oficc: 20th and Northampton Streets. Easton. Pa. 18. No, 1939 General 39 ideation i vl_-itig*tiort of ajiimijiutii du>< as a poswilife respiratory r0Ce** con i;Jzard resulted Irotn the appearance in 1934 at the Oc- *ubstasta ^jpational Disease Clinic, Berlin, of a patient wbo bad been > consistia jpravioj aluminunt bronze for nearly a year and wbo id salts, v .doited sisTM of a lung disease of a not very clear character, ferric eon sr]y in 1934 an Italian doctor of the throat and nose provide, -i,nic at the University of Rome published bis observa- sOj. to th Tjons upon the effect of aluminum dust on the air passages. ' precipitaj The present research includes (1) the components and vropeftics of the substance (-which docs not occur in na- - `ure in metallic form but is the result of mechanical and l.'IS, Sept ^emical processes), (2) 30 citations of previous studies on me a stab) ^te injurious effects derived from the preparation of ~rcparuifi dureimun and its industrial uses, (3) the-detailed case* molecule history of the patient, with laboratory finding* and Roenl- -ft of silica studies, (4) an intensive investigation of 70 workers sufficient jn aluminum works, and (5) a critical analysis of the tion of sutJ Italian data. The hazards were found to be completely he temper*! negative, botb in the processes of making aluminum and :h to tram* irom inhalation of the dust. K.R. h substaoj" Inhalation of dust and control of dust hazards. W. C. J James. Concrete. Cement Mill Ed.. 46, 200-201, 216-17 T93S).--Many persons inhale excessive dust into their lungs, with coal and iron-ore dust coloring the lung tissue. In most cases, however, these changes are of no toore im portance than callouses On the hands. Only two dusts actually cause diseases on inhalation, silicon dioxide (us ej. Akoh ually quartz) and asbestos. Only particles below 10 a ulicosis de are effective, and these must be breathed in high concen letals mon tration and over a long period of time. A sale maximum 1 infcalatiot concentration is 5 million particles of quartz dust per cu. and clinic* ft. The exposure of each man should be reduced, to Of artificial particle-hours to be comparable. The length of time es not con necessary to develop silicosis is controlled by (1) con of silicosis centration of dust, (2) proportion of free silica, (3) length id. of exposure, and (4) general health of the employee. It . MJi. is unusual to have silicosis develop in ten than seven years. iciency and! Dust should be removed at the source. W.D.F. (20) 37-50 Occupational diseases of the lungs In agricultural work iliiaied bjf ers, Richard Fawcitt. Brit. Jour. Radial., -I l, 378-62 mg systeml June, 193S).--In 1930, "49.700 persons were employed in t conveyers,' the agriculture of Great Britain, forming one of the largest :g extensive! working groups. F., as a country practitioner in the - of the old! hills of the Lake District, early became familiar with the material tef -.rricultural types of asthma, bronchitis, and pneumonia wo or three! which usually ran a protracted course among these workers; H.E.S. 'ifovtry, when occurring, appeared largely due to potas- I*. S. Pui -iutn iodide and creosote administration. The infections article, rep-i :he working people are subject to are listed as organic ft selectivei matter (microfungi. and bacteria) existing in grasses. re materiali >tw. grain, fruits, the soil, and in the excreta of fans tat ire docu-1 animals; only occasionally does inorganic matter affect rol has evi-[ them. e.',, men carting siliceous stones. The details of lealing with] iungi infection and the procedure in identification are erasures art; briefly and dearly given: typos of fungi predominantly resourceful- affecting six special group* ol farm hands, t.j,, hay or gTain ibed. Stress workers, stablemen, gardeners, etc., are described, with intended to 4,k-.- resulting symptoms and injur}*. Nine points to be by lengthen vuasidcred in a' doctor's study of such cases are sysicmat- taminatiom `-ally _ presented for case-history record. Special cotti- to allow the is made upon the agricultural groups, with citations out process, 'rivtn case reports; 13 largc-sizc radiographic rcproduc- K.R. 'i>>ns of chest phenomena in the various fungi invasions -IX StSCElt. ' < <ncerncd arc interpreted for t he lav reader. F. emphasizes liscusses the :hvre occupational diseases as rare, seldom reaching radio- lies and the ii-cical departments or diagnosis.- Yet common micro :t with such, fungi, often innocuous, do become pathogenic under cer ay minerals tain conditions. The incidence of harmful infection is er increased .-wire common and more widespread than is generally Ibid,, 15551 ri-ali*ird, 19 references. K.R. id shapes b Practical significance of silicate research. A. Dietzel. itijh Fatentf n.ew/t. Ber.. 14 [5| ltil-64 (1930). J.F.H. 'Process for Prevention of disease in industry. D. Hunter. 2nd. the like ot v i:r< sit, 13, 134-36(1937).--Thu main principles underly RA.H. ing the prevention of disease in industry arc (1) protection n, especially -! workmen by law such as workmen's compensation acts, Grxcrbehyt 2. medical inspection under state support, (3) education tircntph io- *' *" the nature of tlu- danger. I4\ importance of dean. liness (cleanliness of work places, bodily cleanliness, and teflcral hygiene), and (5) reduction of manual operations. H.E.S. Preventive measures is the use of crystalline silica. M. M. Snare*. 2nd. Med., f 18} 472-75 (1938).--S. pre sents the subject systematically under three major as pects: (A ) medical. IB) engineering, and (C) managerial. He suggests that, before any protective measures in the use of crystalline silica are resorted to. the fact be estab lished that * silica hazard exists. Data involved include (1) a definite exposure to dust known to contain a certain percentage of silica and (2) sufficient dust exposure, as estimated by dust count and dust composition, to cause silicosis if the exposure is continued over a sufficiently long period of time. In emphasizing (B), S. states that it >s entirely the problem of the engineer to prevent silico sis, The medical director can only cheek the adequacy of the engineer's methods of' control. JCJL Recovery metabolism of silicotic*. A. Bouts. Arch. Getoerbepaih. St Geieerbekyg., 3, 601-10 (1938).--B. re cords the metabolism studies and muscular tests applied to silicotics in varying stages of the disease to improve their greatly impaired respiratory capacity and muscular action, if possible, and at least to record the success or failure of such efforts. Tables show a comparison of the metabolism of normal persons after 15 bendings of the knees (as in climbing stairs), alter taking food, and after rest with the metabolism of the silicotics (four having a lessened industrial capacity ol 80% and six lessened to 50 or 60% capacity). Items tabulated include age and vital capacity after food and after rest; respiration, minute volume, and Ot requirement; the respiratory quotient, conversion rise in %, and these values after rest; and the Or needs (ec./min.). In the severest forms of silicosis, the total variation in the 10-min. recover}* periods was higher than the highest, shown in normal persons. Acid ab sorption had not returned to normal after 10 min., while in normal persons it was completed in 3 or. at most, 6 min. The minute values of respiration in the most severely ill subjects was markedly raised after the work attempted, and even after the 10 min. rest, it did not attain its pre vious value. The higher the lessened capacity for work in percentage value, the more the records varied in severe silicosis. Experiments on early or middle-period sili cotic* showed fewer certain, unmistakable results, their working capacity being still much higher. K.R. Research laboratories of Mellon Institute. Harry S, Coleman. 2nd. Eng. Cheni,, Anal. Ed., 10 [9] 550-58 (1938).--The desipr. construction, and equipment of the research laboratories in the new Mellon Institute building are described in detail. Illustrated. . F.G.H. Research laboratory of the Columbia Chemical Division of the Pittsburgh Plate Glass Co. Anon, 2nd. n Chem., Anal. Ed.. 10 [6] 329-30 (1938).--The physical equipment is briefly described. Illustrated. F.G.H. Safety andJiygiene in the foundry: I, Medical aspects. R. R. Jones. Trent. Atner, Poundrymm's Assn., 8 12) 554-64 (1937).--The more important industrial health problems associated with the foundry industry are those related to (a) general physical characteristics of the build ing. (5) housekeeping practices, (e) drinking water supply and lunchroom and toilet facilities, (rf) exposure to extreme temperatures, (e) exposure to toxic or irritating dust, fumes, and gases, and (/} medical supervision. Success m the control of industrial health hazards is primarily de pendent upon the employer's attitude toward the problem. Discussion. J. A. BitrrTO.v st al. 2btd., pp, 576-83. H.E.S. Hermann August Seger. Anon. Bull. After. Ceram. Soc.. 17 (11J 463-04 (193S). Silicate resesrch and engineering. W, Eftel. Z. Ter. Dent. 2ng., 80 [21 37--11 (193u).--The conditions and status of silicate research as carried out in the Raiser Wilhelm Institute in Berlin with regard to glass, ceramics, cements, mortars, and concrete and the relation to ap plication in practical engineering are explained. M.H. _ Silicosis among grinders. J. L. A. Grout. Bril. Jour, Radial.. 11, -HiO-TH (June. I93SV--This interesting , No. 2 1 and ns-' . If tie too, they .ck in all however. * are reben and :o photo-, t having: .* a single, ne points surfaces. . Debye the fora c X-rays e lengths e length, diffracted that they . the prim-' n on the s formed, the roeat* made is, xaminiti(.: .vs where, way that: diagram.. ler inter-, f Debyed by tv is turned" the tiny, of curved . Roentboratones Id (11 32 M.V.C. ed. " Ost . Leipzig, . 15o5| reedited; . jf ceramic chemical are raea; booh is RJl,H. materials, liing Co.). a silicate- . X PROt. 9. 1938 cCcuocb 2,137.058. with high ck. Geverbe authors ,oc to high jeh as are water<onconditioos. . high ten*- as such is s) decrease conditions cr. so that 1 as a full* 1W Central S3 dme labor limit in the German hard-coal industry for 4rv atmospheric localities, is an arbitrary limit,. In general. working capacity seems to be lowered by high vtmperaturcs to values. The physiological reactions of men continually wary when climatic conditions grow constantly worse. Injury to health from dry and high temperatures alone can not be definitely established, the relation to humidity present always being a factor. Omit ting the heat factor, a humidity of 25* seems endurable, tn regard to the elimination by the shin or lungs under high and humid conditions, results appear personal and individual. Greater water elimination occurs in men acclimated to hoc humid air than is those sot inured. Men habitually rather than occasionally at work elimi nate larger quantities of water. Rising temperatures in a dry climate and rise in humidity increase elimination of. water through the skin. Individuals showed, is their elimination through the skin, none of the expected cor respondences which might be traced back to these chang ing environs! states. In this investigation, bodily tem peratures generally rose very little proportionally under higber outside temperatures and increased humidity. Blood pressure, respiratory frequency, and pulse frequency showed no quantitative relation to selected climatic con ditions. Fourteen diagrams and two tables are given. 18 references, X_R. Dust content in an asbestosis lung and the behavior of the so-called asbestosis bodies. X. Si.'NDtCS ajtd A. BygoeX. Arch. GczL trbepath. S'. Geverbthyt., S4 28-70 (1937-1938).--This research upon the effects of asbestos dust when breathed in by industrial workers in asbestos was carried out by the State Geologist and the State Chemist of the Swedish Geological Survey. They indi cate the differences between the asbestosis lung and the sSicotic, the former being due to the action of a basic silicate (isotropic) accumulating in yellowish or reddish- brown needle-like masses, and the silicotic being due to quarts (SiCt) degenerative action, exhibited in nodules and other quite different manifestations. Asbestosis was first identified in 1906 by an English physician, Montague Murray, of the English Compensation Com mittee of Industrial Diseases. The chief research studies since that time are reviewed by these authors in their cumulative value. Their own procedure in isolating asbestos dust and its accompanying "asbestosis bodies" bv treating the affected lung substance with hydrogen peroxide, also by purely mechanical action upon a "heavy" solution, is given together with the ascertained percentage values derived chemically from the eight or more mineral components of asbestos. For the entire lung, approxima tions were 5.8 g. asbestos bodies, 0.3 free asbestos needles, and 1.4 total asbestos content. Total dust respired by the given lung was about 2.5 g. Some of the bodies built up in needle form were composed of titanium oxide (TiOJ. Intensive study and analysis of the coverings of the bodies seem to indicate that they are blood derivatives after the mineral has entered the lung. The fibrosis ultimately' and generally distributed through the lung following the' dun inhalations appears to have definite relation to the presence of the asbestos needles and their movements wbout the lung under the mechanical stimulation due to respiratory movements. 12 photomicrographs. K_R. , Heinrich Ries. Ajeose. Suit. Amtr. Ceram. Joe.. 17 ;12; qPCM*l 11938). History of glass industry at Hew York World's Fair. Anus-. B h. ri w*r. (Vein. Soc,, 17 (121489 (1938). Hygienic dangers of non/errous metals. H. BesCEk. jfr.'s/lirfrfsrfcn/), 17 [32] Stili-iiT (1!KS3).--B. discusses the dangers in handling Pb, Hg. Zn. Cd. As, Yb, Se, Te, Cr. Nt Cu. Mn, light metals. W, Tl. and Os due to inhalation of du?t or vapors or contact with each individual metal and fflvans for eliminating or at least minimizing the risk. , M.H. hung findings tn foundry workers. O. A. Sander. A`tr. Jour. Pub. Health. 28, 601-609 (1935).--Of the variou* occupation* in foundries, sandblasting is the most ^rarduu* if done without protection; otherwise sand `'nipping and grinding of large castings arc the most danger ous in regard to the health of the employees. Data obtained during a four-year survey are as follows; Yon tipMun 1- 5 6-10 11-15 lfr-20 '21-25 26-30 31-40 41-50 No. mptoifM 1174 812 602 532 305 268 215 47 - SiHcwfe 0.5 3 5 10 *1v5 21 - 2] Prom this data. S. concludes that simple silicosis as seen in foundry workers is only very slowly progressive, so much so that no visible changes appeared is four yean observa tions, and is only rarely sufficiently advanced to cause symptoms and incapacity lor work. Control of the foundry hazard is best accomplished by elimination at its xourcc of the dust generated by sandblasting, sand chip ping. sand grinding, and shake-out operations. Pre employment and periodic examinations are essential to prevent tubercular individuals from carrying on a dusty trade and to discover new infection and reactivation cases as they arise. B.CJL Selenium aa a potential Industrial hazard. H. C. Dudley. U. S. Pub. Health Repit.. 33 |8| 231-92 (1933). ---D. points out those industries which may hive un recognized hazards due to the possession of selenium bearing materials. Increasing uses and applications of the element and its compounds necessitate the warning that in certain combinations selenium is toxic. Hence, in dustrial plants where these substances are utilized will need to afford their workers adequate protection. Sele nium is obtained as a by-product from electrolytic refining of copper; this is the chief commercial source. Its first use was largely confined to the glass and ceramic industries, where it was used as a glass decolorizer and for the pro duction of red glass and glazes. Rubber manufacturers next made heavy demands on domestic copper refineries: recent increased uses have not only exhausted domestic supplies but have required importation in larger and larger quantities. The ceramic industry alone has utilized more than 170,000 lb. According to D,, new sources of supply will have to be opened. The Occur rence and location in 21 states of 15 minerals, with the selenium parts per million, are tabulated. The selenium content of the earth's crust has been approximated at 0.005%; nearly all sulfur and sulfide deposits contain it: certain western phosphate rocks show amounts of even 55 parts to the million. In a large number of sod samples taken from areas surrounding smelters near Butte and Anaconda, Mont., Kennet. Calif., and Copper Hill, Tenn.. selenium was found: it decreased in quantifier with distance from the smelter. Extensive animal experimenta tion by ingesting selenium compounds shows that such substances, when soluble, have toxic effects, both acute and chronic. Early cellular destruction occurs in the Href, with later pathological characteristic changes throughout the organism, Guinea pigs experienced severe metamorphoses in the liver and. after inhalation of hydrogen seienide, hypertrophy of the spleen. Men employed in copper refineries which extract or purify selenium display the symptoms, respiratory and gastric, which' characterize metal poisoning generally. The excretion of selenium tn the urine, however, is conclusive evidence of selenium absorption by workers. D. gives in detail the procedure for urinalysis in detecting and estimating selenium in the urine. In the tabulation of industries with possible selenium hazards, the glass and ceramic industries are in the secondary group, t'.r., they utilize sejenium and its compounds as basic materials in manufacturing processes. The immediate sources of hazards involved in this group are given as melting pots and furnaces, the fumes of Se and SeO; being given off. The sampling of vapors and gaseous constituents of in dustrial plant atmospheres and contaminations of labora tory workrooms is explained in detail in connection with Ctmmic Abstracts Vol. IS, No. -i ttjtj and indicating just (tow closely the sampling rcpre- seats the true character of a batch of material being cared. F.P.P. Volumetric analysis of copper. M. Sixers, ano V. YvOtAJtOTO. Jour. Sot. Ckem. tad. Japan, 41 (21 34B (1933).--Copper can be reduced to Che cuprous ion in on alkaline solution with sodium sulfite. This cuprous ioa cu be titrated with potassium permanganate solution. After the reduction is complete, the solution is acidified to expel the excess sulfur dioxide gns. As addition of a small amount of chlorine ion its the form of sodium chloride is necessary to avoid the precipitation of cuprous oxide. The sample of solution containing about O.ld g. of copper should be treated as follows; pour the test solution into n 300-cc. dasIt. dissolve it in a small amount of water, and moke it slightly acid.* either with sulfuric acid or sodium hydroxide solution; add 50 cc. of 10% solution of sodium nitrite and 0 cc. of 10% solution of sodium chloride; boil and redissolve the yellow precipitate in the dash (double salt of cuprous sulfite and sodium sulfite) and make the solution colorless; odd 50 cc. hot sulfuric acid (prepared at this time by mixing 20 cc. of -'Pi .V sulfuric acid and 30 cc. of ti .V sulfuric acid). The white pre. cipitote of cuprous chloride is formed, and sulfur dioxide gas is expelled violently. Boiling is continued for 15 :j 20 min. to expel sulfur dioxide gas completely and to expel excess hydrogen chloride. To fill the tkuk with carbor. dioxide, M cc. of 3% sodium carbonate solution are added Heating is discontinued and the solution is titrated wi;- 1/10 <V potassium permanganate solution which contain* about 3% sodium carbonate. The presence of Pb*. fin ' ". Mn*. etc., tins no effect; therefore, no preliminary scpa.-i. tioa of these metals is needed. M.V.C. PATENTS Making alkali metal silicates. G. R. McOa.viu (Diamond Alkali Co.). t\ S. 2.153.572. April 11, it*;-. (March 7. 1936). Production of polysilicate*. Dcssaltc Fils. Pr. 732. Oct. 3. 1937; Chtm.-Zit., 63 [19| 173 (1939). D.A.3. Genera I Air conditioning in industry: I. \V. L. Flsishi*. A. between liquids' and gases, as it presents the gaseou.t E. Stackv, F. C. Hoccrten. ano M. B. Fuoustt. reactant in the form of minute bubbles, thus giving tl* Heating. Piping S' Air Conditioning, II [2| I07-U maximum surface for reaction. (2) Biscuit porcelain U (1939),--This study was conducted in the research labora used in filtering operations where it is necessary to sept, tory of the American Society of Keating and Ventilating rate extremely minute particles from acidic or other cor Engineers at the Pittsburgh Experiment Station of the rosive liquors. It resembles porcelain in color and com U. S. Bureau of Mines. The physiological.reactions of position. but differs from it in that it is highly porous. I;j men while carrying on light work in atmospheric condi pore dimension can be regulated ia size from 15 microti tions including effective temperatures from n* co 92*p down to below l micron. The 'nature of its ingredieau with relative humidities of 60, 75. and 90% were inves - and the temperature at which it is fired ensure resistant: tigated. The history of previous investigations is dealt to adds by the more siliceous bodies or to caustic alkali; with. Two charts. 7.L.G. (where the alumina content predominates). Buck Appearance end prevention of silicosis and asbestosm porcelain is also used for electrolytic processes in ti: E.vatco C. VtsuANt. Ross, ited. Applieata Iaw* filtration of oils and concentration of rubber latex. <-* lad., 9, 387-94 (1933): Ckem, Abt.. 33, 2244 (1939).--A Diatomaceous or kieselguhr bodies, while less reststac: review is given. to corrosive chemicals than either biscuit porcelain cr Aabestosis. R. R. Savkes and IV. C. Drsesen, Amtr. quartzite, combine small pore size with high permeabilit? Jour. Pub. Health, 29 (3| 205 (1939).--In a study of the and are used for the filtration of neutral, or nearly neutri. North Carolina textile mills using asbestos fiber, a hy liquids. They are usually employed in the form of caccls drated magnesium silicate containing no quartz, pul or hollow cylinders of small diameter, closed at one --; monary asbestosis was the principal defect found. Ex or with both ends open, up to a length of 12 in. A. 3-5. posures ranged from 0.10 to 76 million partides/cu. fa. Floors for industrial purposes. R. Firzstursics ax Persons exposed, from 5 to 10 years to dust concentrations F. M. Lea. Read before Inst. Chem. Eng. and In exceeding 5 million partides/cu. ft. showed definite struct. Eng., London. Jan.. 1939; abstracted in Ckt-. evidence of osbestosis. Data so for obtained indicate Trad* Jour., 104, 79-80. 112 (1939). L.R.B- that 5 million partides/cu. ft. is the maximum safe IndustrUt impairment of health and poisoning in & concentration. - - B.C-R- metal-working industry. FaxiTAG. Ober/Ucnentech.. It Ceramie filters. Anon. Ckem. Age (London). 4QV (41 35-36 (1939).--F. dtytitsev the danger of silicosis 45 (1939).--A new range of porous ceramic filtering mate men working with sandblasting. 'Poisoning by aitra.? rials has been introduced by a Glasgow firm. These gases in pickling, etching, and coloring processes, by C: . ceramic materials are resistant to corrosive fluids and are salts us Cr plating, by Pb its Pb welding, by CO In oxy ` made with a pore size ranging from below one micron up acetylene welding, and by toxic gases developed in nitrii- to several hundred microns, the distribution of pores and ing and hardening processes is also discussed. M.K._ pore density being exactly regulated. The materials are Lila and work of He7 LeCkatelier (1850-1936). produced in a great variety of shapes--they can be Pascal. Bull. Soc. Chim. item., (5| 4 (U)| 1557-Wf- sawed, cut, or ground to suit individual requirements-- (1937); see Bull. Amtr. Ceram. Joe.. 16 [4| l55-*i3 (19:" and their mechanical strength and durability are very Cew. Ads.. W [10| 316-22 (1937). D.A.S. high. The materials, quartzite, biscuit porcelain, and diatomaceous or kiesdguhr bodies, ore described as fol lows: (1) Quartzite filters in the form of square or circular tile, of different thicknesses and sixes, and hollow patents . Repairing camant tot ceramic objects- E. Rosentx*. cylinders from 2 in. to 6 in. in diameter sod up to 24 in. Brit 500,375. Feb. 22, 1939 (Aug. 12, 1937). .; long are produced in several grades, varying from coarse Satin whit* pigment and procesa of malting. L-* ' grained bodies of extreme permeability down to a close Woojl. U. S. 2.145,149, Jan. 24. 1939 (Feb. 4.1935). & 1 grained type with a pore size as low as 10 microns but of process comprises creating finely divided day with suif-1; such high pore density that it ensures rapid permeability. acid, producing thereby a solution containing ilurr.in-- The-high rates of (low obtainable with these filters ore sulfate together with coloring impurities and an iasc<;' exemplified by the P27 grade which gives a dow of 1700 day residue,removingcoloring ingredients from the ; gallons of water/sq. ft,/hr. at 5 lb. pressure. Quartzite tion, and reacting the so-purified solution with hydra:*-; filters are particularly suitable for industrial filtering and lime in the presence of the clay residue. _\ aerating operations of liquids and gases, especially where TUe for use in sewage filters. J. E. Tcckex. 3" ) resistance to corrosive fluids is essential and in reactions 500,378,Feb. 22.1939 (bept. 15. 1937). j .l {