4% a Of m4 CORNELL UNIVERSITY LIBRARY ENGINEERING LS aR Cornell University Library ii IMPERIAL MINERAL RESOURCES BUREAU. THE MINERAL INDUSTRY OF THE BRITISH EMPIRE AND FOREIGN COUNTRIES.. WAR PERIOD. FULLER'S EARTH. (1913-1919.) LONDON. PRINTED AND PUBLISHED BY HIS MAJESTY S STATIONERY OFFICE. To be parokiee through any Bookseller or directly from H.M. STATIONERY OFFICE at the following adaresses: IMPERIAL HOUSE, KINGSWAY, LONDON, W.0.2, and 28, ABINGDON STREET, LONDON, 3.W.1; 37, PETER STREET. MANCHESTER ; 1, ST. ANDREW’s CRESCENT, CARDIFF; 23, FORTH STREET, EDINBURGH ; or trom’ BE. PONSONBY, Lrb., 116, GRAFTON STREET, DUBLIN 1920. Price 6d. Net. Ww GT, BIT TmePeeiAl INSTITUTE , London, TN oe bi, PREFACE. - / , tne following digest of statistical and technical information relative to the production and consumption of fuller’s earth will constitute a part of the Annual Volume on the Mineral Resources of the British Empire and Foreign Countries. In this the first year of publication an effort has been made to fill in, as far as possible, the hiatus due to the war in the publica- tions relating to mining and metallurgical. statistics. Labour, health, and safety statistics have been omitted owing to the diffi- culty involved in procuring reliable information for the war period, but in future issues these statistics will be included in respect of each year. , Resort will also be had to a much greater extent than at present, to graphical representation of statistics of production, consump- tion, costs and prices. R. A. 8. REDMAYNE, Chairman of the Governors. June, 1920. 2, Queen Anne’s Gate Buildings, London, §8.W.1. £E60503 Ad CONTENTS. Page. GENERAL ... By st a ae ak ie iis Gan 4 PRODUCTION a sas re we ae ee sis a 4 BRITISH EMPIRE: Unitep Kinapom INDIA AUSTRALIA Sale sii a ies art ake ee sae 9 FOREIGN COUNTRIES : UNITED STATES... aes eas seis ie woe si Mee 9 REFERENCES TO TECHNICAL LITERATURE slis hts 13 APPENDIX. NOTE ON THE NATURE OF FULLER’S EARTH aan mi 14 (28734) Wet. 6695 41/748 1000 7/20 H.St. G.2 GENERAL. Fuller’s earths are clay-like materials, usually non-plastic, and of a greyish, yellowish, greenish or bluish colour. They are essentially complex hydrated silicates of aluminium, with variable amounts of iron oxide, magnesia, lime and alkalies. They are characterized by the fact that they absorb grease, for which reason they have been used by fullers to remove greasy matter from woollen goods, hence the name fuller’s earth. They have also the property of absorbing colouring matters, and on that account are largely used for decolorizing oils. It is by the posses- sion of these two affinities for grease and basic colouring matter that fuller’s earths are characterized rather than by their chemical analyses. The chief use of fuller’s earths at the present time is for the decolorization and clarification of oils. It is used also as a carrier for certain pigments, as a filler for paper, as an ingredient of some soaps, and for medical and toilet purposes; and it is serviceable in detecting colouring matters in certain food products. It is worthy of note that the United States removed practically all restrictions on the importation of fuller’s earth at the begin- ning of 1919, as it was thought that the supply of fuller’s earth suitable for refining edible oils in the United States was not equal to the demand. The United States earth is quite suitable for use in refining mineral oils, but many consumers appear to be of opinion that it is inferior to imported earth for the purpose of refining edible oils and fats. The requirements of fuller’s earth for refining edible oils in the United States are as follows :—(1) That it shall bleach well and that the oil shall not revert to its original colour; (2) that it shall filter well and not cake badly; (3) that it shall leave no permanent disagreeable taste or odour ; (4) that the retention of oil in the spent earth shall be small ; and (5) that there shall be no spontaneous ignition either in the press or in the waste piles. Many American consumers seem to think that the English earth fulfils these requirements better than does the American earth. PRODUCTION. England was formerly the chief producer of fuller’s earth, which was exported from the country in large quantities. In recent years fuller’s earth has been produced in increasing amounts in the United States of America, whence it has been exported to Furope, notably to Germany. The comparative out- puts of the United Kingdom and the United States during the period under review have been as follows :— 5 Comparative Outputs of Fuller’s Earth in United Kingdom and United States. (In long tons.*) Year United Kingdom United States 1913 bia 2 31,609 34,459 1914 sn en 37 862 36,590 1915 sé od 29,298 42,769 1916 ate sie 29,106 60,555 1917 cs zt 27,916’ 64,792 1918 3 mad 23,290 75,418 1919 ae Be 24,785 BRITISH EMPIRE. United Kingdom. Fuller’s earth has been worked in Great Britain in a number of places, but at the present time the largest works is situated near Reigate, Surrey, where the large quarry owned by the Fuller’s Earth Union, Ltd., employs upwards of 45 men. The quarry of the Surrey Fuller's Earth Co., Ltd., at Nut- field in the same district, is next in importance, and there are three mines in active operation at the present time in the same neighbourhood. The earth is found in strata of Cretaceous age, a section of which, according to Dr. A. H. Cox, shows the following sequence :— — (i) Clayey glauconitic sands ... obs ... 20 ft. (ii) Mottled bluish calcareous sandstones weathering grey, with interbedded seams of fuller’s earth ... is ik ... 20-25 ft. (i) Fuller’s earth ve ne ee ws 10 ft The whole series dips down the hill at an angle of 3 to 5 degrees. The fuller’s earth bed sometimes reaches a thickness of 12 feet, and, as arule, the upper portion is oxidized to a brownish colour by the action of percolating water, the lower portion being blue. In Somerset fuller’s earth has been worked at a number of places in the vicinity of Bath. It is found overlying the Inferior Oolite and is covered by the Great Oolite. The limestones of the Infenor Oolite contain fuller’s earth in the cavities. The sequence of beds is as follows :— 1. Blue and yellow clay with nodules of indurated marl ... oe ... 80 feet to 40 feet. 2. Bad fuller’s earth abe 4X cae, ABI 5 Duss 3. Good ,, 5 sae oe wee, gy See 4. Clay containing beds of bad fuller’s earth and layers of nodulized lime- stone and indurated marl... sy 100 feet. * The long and short tons referred to in this publication are equivalent to 2,240 Ib. and 2,000 Ib. respectively. 6 The two mines now worked are Coombe Hay and Midford. The Bureau is informed on good authority that for use as a clarifier the blue Somerset earth is as good as the Nutfield earth. The Somerset blue earth contains a considerable percentage of calcium carbonate (see analysis below). _Other notable deposits of fuller’s earth include those of Woburn Sands, in Bedfordshire. The evidence of borings and sinkings indicates that these are co-extensive with the Oxford clay. A superior quality of fuller’s earth is procured from the Lower Greensand at Aspley Heath, Bedfordshire. The water thrown out by this formation is very soft and pure, and blocks of the earth have on this account been used for the purpose of purifying water in wells. The following analyses* showing the composition of various English fuller’s earths are taken from the Geological Survey Memoir on the Jurassic Rocks of Great Britain. (Memoirs of the Geological Survey, 1894, Vol. IV., p. 491.) 1. 2. 3. 4. 5. — Nutfield Midford | Midford | Woburn | Woburn Earth Blue Yellow Blue Yellow ayes Earth. Earth. Earth. Earth. : | Silica Said sy .. | 58°66 54°0 | 59°73 | 60°00 56°9 Alumina... wee sie 17°33 18-6 } 20°8 © 75°2 15:7 Ferric oxide a eee 7°21 2 a 4:2 ! 7:8 925 Ferrous oxide owe — ms) _— 127 “1 Lime ‘ie ia ae 3°17 7:0 2:5 2-7 2-1 Magnesia... ss a 3°26 2°33: 1:9 3°3 2°7 Soda ie he ve \ 1-63 J a 6 =D “3 Potash ... as ee 18 | 1:7 6 ath Carbonic acid... or —_— 3°4 3 — — Loss on Ignition (not 8°74 Qe 86 | 8:4 11:9 including carbonic \ acid). 100-00 997 999 99°9 99°9 A bed of clay described as fuller’s earth occurs at Rhiwlas, Frongoch, near Bala, North Wales. The beds are about 60 feet thick, and samples analysed by P. G. Sandford show very much the same composition as the earths at Nutfield referred to above. Their appearance, however, is different. The Surrey earth is greasy to the touch, and has a comparatively hard, smooth surface. The Frongoch earth is comparatively soft and friable, dark grey in colour, and dissolves in water to the extent of about four per cent. of its weight. Sandford states that this earth appears to be even better than the Nutfield samples as regards the grease-absorbing properties. * Analysis (1) is of purified fuller’s earth and was made by B. Dyer, July, 1885. j Analyses (2), (3), (4) and (5) were made by J. H. Player, for the Geological Survey in 1890. 7 The following are analyses of two samples by Sandford of the Frongoch earth*® :— No. 1. Sample A. Per Per cent. cent. Insoluble Residue 78:27= ¢ Silica 63°25 Al,O, 12°95 | Fe. 8°72 Fe,0; 0°42 ALO; 6°30 MnO trace CaO 0°82 78°27 MgO 1°65 sO, a 0°31 Alkalies ee 2°02 Combined H,O 3°56 100°0 No. 2. Sample B. Per Per cent. cent. Insoluble Residue 78°53 = ¢ Silica 5701 Al,O, 284 Fe,0; trace Fe,0; 850 ALO, 24°52 MnO trace CaO 0:90 78°53 MgO 2°30 SO, ae 0°05 K,0, Na,O_.... 2°12 Combined H,O 4°76 100°00 Production of Fuller's Earth in the United Kingdom.+ (In Long Tons.) County. 1913. ; 1914. ; 1915. | 1916. | 1917. | 1918. 1919. Bedford (from mines) «. «| 640| 630! S90) — = = a Gloucester (from | : mines) ... ae — — _— es te tee — , 495 Somerset (from i mines) ... ... | 3,559 | 4,256] 4,425 | 5,577! 4,109 | 3,783 | 3,469 Surrey (from quarries)... ... | 27,410 | 32,976 | 24,283 | 23,529 | 23,807 | 19,507 | 20,821 Tota... — ... {31,609 | 37,862 | 29,298 | 29,106 | 27,916 | 23,290 | 24,785 * Geol. Mag., 1893, p. 160. + Figures supplied to the Bureau by the Chief Inspector of Mines, Home Office. 8 Value of Imports of Fuller’s Earth to the United Kingdom.* Value Year £ 1913... oe ty) ae is nil 1914... sie os i ee nil 1915... Sad i Li aks 11,649 1916... a ae bt Aa 4,808 1917... a0 coe aa as 2,577 1918... EG bee pe basta 4,038 1919 ie Value of Exports of Fuller’s Earth from the United Kingdom.* Value Year £ 19138... Si wis er ve 48 ,882 1914... ee on a ae 56,451 1915... #4 ae hes poe 47,208 1916... a a fa as 44,427 1917... st sia ele ae 49 ,949 1918... eee sak sy ai 538,789 1919 India.} The statistics of Indian fuller’s earth and similar clays are incomplete. The mineral is probably obtained in small quantities at numerous localities. It is used for the washing of clothes, and constitutes the principal part of the various edible earths which are sold in the bazaars. The earth-eating habit is prevalent throughout India, Burma and the Shan States. A table is given below showing the annual production of fuller’s earth at Katni, in the Jubbulpore district of the Central Provinces, where it occurs in the Lower Vindhyan Series. The average annual output for the five years 1914 to 1918 was 196 tons. A form of fuller’s earth known as ‘‘ multani-matti’’ is also worked in the States of Bikanir and Jaiselmer in Rajputana. In 1913 a production of 1,000 tons was returned for Marwar in Rajputana. Outputs of 30 and 52 tons of fuller’s earth in the years 1911 and 1912 respectively are recorded from the Anantapur district of Madras. * Annual Statement of the Trade of the United Kingdom. t Records of the Geological Survey of India. Annual Report of the Chief Inspector of Mines in India. 9 Production of Fuller’s Earth from a Limestone Mine at Jubbulpore, Central Provinces, India. Quantity Year. (long tons). 1913 a se oie ae vite 103 1914 a8 ii oi sor det 109 1915 pais on Be ke ite 139 1916 by ie wi on ee 179 1917 aad a as a ssi 334 1918 es as si _ wait 218 1919 Australia.* A deposit of fuller’s earth of considerable size occurs in the Permo-carboniferous coal measures at Wingen, New South Wales. The composition of the earth is as follows :— Silica... oe ss bel Dees 50°61 Alumina a on 23 on 19°35 Ferric oxide... ste ie ae 3°55 Lime... ee 32 i ee 1:37 Magnesia Sud de aoe is 3°24 Potash se a bay mies 4. 292) Soda... ae tic “47 Phosphoric anhydride as sie trace Moisture ios i nor se 13°73 Combined water Dats hs ae 6°45 99°69 The only outputs recorded for the period under review are 110 tons and 20 tons, for 1916 and 1917 respectively, from the Narrabri Division. FOREIGN COUNTRIES. United States.+ Deposits of fuller’s earth have been found in a number of States, including Florida, Georgia, Alabama, Arkansas, Colorado, New York, South Dakota, California, South Carolina and Massa- chusetts. At first it was entirely used for ‘‘ fulling ’’ or taking grease from woollen goods, but owing to the cheapness of good soap, this use has almost wholly ceased. Fuller’s earth was discovered in Arkansas in 1891 and is still mined at Benton. Jater it was found at Quincy, Florida, and the deposits in this neighbourhood have since furnished all the fuller’s earth required for the refining of mineral oils throughout * Min. Res., N.S.W., by E. F. Pittman. Ann. Reps. Dept. Mines, N.S.W. + Ann. Reps. Min. ’Res., U.S.A. Bull. No. 71, U.S.A., Bur. of Mines. Foreign Commerce and Navigation of the United States (Annual). 10 the States. These earths have not, however, been much used for bleaching fats and vegetable oils, whilst the Arkansas earth is used wholly for edible oils. With the exception of the Arkansas deposits all the known deposits of fuller’s earth in the United States are of sedimentary origin and occur under the same conditions as any clay beds. The Massachusetts deposit is a glacial silt and is the only known glacial silt to be so classified. It is mined at Lancaster and the earth is used wholly in the place of alkali to remove surplus dye from woollen goods. The Arkansas fuller’s earth is unique in that it occurs in the form of veins or dykes. Its formation is attributed to the alteration of basaltic dykes. The deposits are situated about seven miles south of Benton. There are numerous dykes, some of which have been mined, one to a depth of 140 feet. The dip of the dykes varies from 45° to almost 90°. The Florida deposits are mainly in Gadsden County, near Quincy, and the southern Georgia deposits are just across the State boundary from this town. A section near River Junction, Gadsden Couaty. Florida, is described as follows :— Surface,sands ... Lae ee es ... 60 feet. Clay and fuller’s earth io 2h og: LO Not exposed, but probably argillaceous sand 17 Chattahoochoo chalk or limestone with some layers of marl the me ... 88 29 3? o) Analyses of Fuller’s Earth of Florida. Place. | SiOx. Als0s. | Fe,03. Cad. | Meo, H.0. | Mois- ture. Hymeson Mine | 59°00 | 15°05 | 2°95 | 0°20 | 3°70 | 11°40 7°8 McPhaul Mine | 58°50 | 14°30 | 2°10 | 1°30 | 6°50 9°50 7-0 McPhaul Mine | 62°85 | 15°36 | 2°25 | 1°39 | 6°98 | 10°20 _— 0 In South Dakota, near Fairburn, Custer County, large deposits occur, the section at the mine, beginning at the top, being :— Micaceous sandy clay ... one we ... 6 feet. Fuller’s earth ... ae as gp asa OF xs Micaceous sandstone ... tack = se — Two miles west of Argyle in a shaft sunk 26 feet the following section was obtained :— Surface pebbles is aes es .. lL foot. Sandstone... bat aa mr .. Id feet. Fuller’s earth ere ie oe . IS ,, Clay and earth oa Be i se 32 »” Sandstone... a8 a sats wey (1D a 11 The following analyses show the usual composition of the fuller’s earths of South Dakota :— Place. SiO, Al 203 Fe.O3 CaO MgO H,;0 Bodenner’s pit, Fairburn .., | 68°23 | 14°93 | 3°15 | 2°93 | 0-875 | 6°20 M. Palmiter, Fairburn ... | 60°16 | 10°38 | 14-868! 4°96 | 1-714; 7°20 M. Palmiter, Fairburn ... | 56°18 | 23°23 | 1:26 | 5°88 | 3°29 | 11°45 D. Henault, Custer City ... | 55°45 | 18°58 | 3°82 | 3:40 | 3°50 8-80 E. J. Riederer, Fairburn ... | 58°72 | 16°90 | 4°00 | 4°06 | 2°56 8-10 These earths are said to bleach as well as the English earths. In South Carolina there is a very large deposit in Williams- burg County, near Salter’s Depét, one in Dorchester County, near Summerville, and one in the neighbourhood of Sumter, Sumter County. In California, fuller’s earth occurs in Kern and San Bernardino Counties. The beds range from 15 to 50 feet in thickness, and are of Cretaceous, Tertiary, and Pleistocene ages. It has only been mined as yet at Vacaville and Bakersfield. In Texas deposits have been found at a number of places, such as Summerville, West Point and Burton. The expansion of the petroleum and cotton-seed oil industry in Texas makes the production of fuller’s earth of importance. Fuller’s earth produced and marketed in the United States.* Quantity | Average price mene short tons. vee | per ton. \ 1913 ks aes 38,594 , sc 750 - 58 1914... abe eas 40,981 403, 646 9°85 1915 l 47,901 489, 219 10°21 1916 67,822 706, 951 10°42 1917 72,567 772,087 10°64 1918 84,468 | 1,146,354 13°57 1919 | ] * U.S. Geol. Surv. Min. Res. Preliminary Report for 1918. 12 ‘SOY “UIP “AING "J09D “SN « 6161 et- et GEa'GoT LOQ'2T ¥3-E1 GE0'ST LOL'TT 19-11 B09 01 006, 8161 88-01 LT¥'921 P6691 89-01 669°F9T eaG'GT 81-8 SILTT PPT L161 1-8 799'6E1 108'91 Zr-8 326 TSI 699'¢T 8-4 OPLiL BELT 9T6L 98-2 E6P'SST 1F¥'6L 36-2 LIG LPL 169°81 60-9 9LU'G 0g8 S161 18-2 €80'96T LL6 ¥% 06-2 008°¢8T 609°EZ 3E-9 £86°6 89F'T FI6I 8-2 TOO‘9FT 89°81 00-8 1499'Ee1 BIL OT vP-9 PPE'AT 916‘T e161 $ $ “su0} 410q9 $ g *st04 41049 $ $ "sa0} 41049 ‘m04 red . : ‘m04 red . 4 m0} Jed - . soll g ese10aAy one HME alg svlaAY ony A Aqqaend alg esvi0Ay one A Anca | i “v9 TRIO], : “‘poanqoeynuep 10 yy sN0T AA ‘pomnjoeynuewmuy) pue yysno1Muy | « SIIDTG papiuyy, ay} 07 uoydwunsuos sof pajsodrua yjuva 8 say)ngy 13 REFERENCES TO TECHNICAL LITERATURE (1913-1919). An early discovery of fuller’s earth in Arkansas, by J. C. Branner; Trans. Amer. Inst. Min. Eng., 1913, 43, 520-522, Excursion to Nutfield and Redhill (Lower Greensand beds), by A. H. Cox; Proc, Geol. Assoc., 1918, 29, 150-152. The rocks and minerals of the Croydon regional survey area, by G. M. Davies; Proc. and Trans. Croydon Natural Hist. Soc., 1915-16, p. 63. Fractionation of California petroleum by diffusion through fuller’s earth, by J. E. Gilpin and P. Schneeberger; Amer. Chem. Journ., 1913, 50, 59-100. Abstr. Journ. Soc. Chem. Ind., 1913, 32, 818-819. Action of Florida earth on unsaturated compounds in petroleum, by L. T. Gurvitsch; Journ. Russian Phys. Chem. Soc., 1915, 47, 827-830. Journ. Chem. Soc., 1915, 108, i, 933-934. Abstr. Journ. Soc. Chem. Ind., 1915, 34, 1234-1235. Fuller’s earth and its importance to refiners, by W. R. Jewell; Mine Quarry and Derrick, 1915, 77-79. Fuller’s earth, by J. Middleton; U.S. Geol. Surv. Min. Res. U.S., Annual. Developed deposits of fuller’s earth in Arkansas, by H. D. Miser; U.S. Geol. Surv. Bull. No. 630, 1913, 207-220. Fuller’s earth in New Zealand, by P. G. Morgan; N.Z. Journ. Sci. and Tech., 1919, 2, 119. Fuller’s earth, by C. L. Parsons; U.S. Bur. Mines. Bull. No. 71, 1913, 38 pp. Preparation of fuller’s earth, by W. C. Phalen; Chem. Met. Eng., 1919, 21, 469. Fuller’s earth and its valuation for the oil industry, by T. G. Richert; Journ. Ind. Eng. Chem., 1917, 9, 599-600. Abstr. Journ. Soc. Chem. Ind., 1917, 86, 893. Clays, their occurrence, properties and uses, with especial reference to those of the United States, by H. Ries; 2nd edn. London: Chapman and Hall, 1914; xix and 554 pp. (Fuller’s earth, 516-527). Utilization of the adsorption power of fuller’s earth for chemical separa- tions, by A. Seidell; Journ. Amer. Chem. Soc., 1918, 40, 312-328. Abstr. Journ. Soc. Chem. Ind., 1918, 37, 136 A. Fuller’s earth, by E. H. Sellards; Min. Ind., 1913-1918 (Annual). A report on the bauxite and fuller’s earth of the coastal plain of Georgia, by H. K. Shearer; Bull. Georgia Geol. Surv. No. 31, 1917, 340 pp. APPENDIX. NOTE ON THE NATURE OF FULLER’S EARTH. The Imperial Mineral Resources Bureau has received communications from Dr. E, F. Armstrong and Dr. J. W. Evans pointing’ out that the nature and properties of fuller’s earth require investigation. Little or nothing appears to be known of any relationship that may exist between the chemical or mineral composition of the earth and its peculiar physical properties, and it seems desirable that this possible relationship should be carefully investigated. At a recent meeting of the Chemical Industries Committee of the Bureau this desirability of research into the nature and properties of fuller’s earth was discussed, and Sir Herbert Jackson suggested that it would be useful to have a more detailed statement as to the nature of fuller’s earth than the one given on page 4 of this report, even if such a statement involved speculative views. The following brief statement is therefore put forward, not in any dogmatic ‘spirit, but as a stimulus to research on this problem. Fuller’s earth, like ordinary rock clays, is of a somewhat indefinite composition. When examined under the microscope it is seen to consist partly of amorphous and partly of crystalline matter. The amorphous base of fuller’s earth is probably closely similar to ordinary rock clay in composition, consisting essentially of hydrated silicate of aluminium with incompletely decomposed mineral matter containing alkalies and other bases. The crystalline matter present in fuller’s earth includes various mineral substances, some of which are clearly detrital. The chemical composition of fuller’s earth suggests that the colour of the fresh earth may be due to disseminated iron silicate of a glauconitic character, the oxidation of which would explain the change of colour in fuller’s earth on weathering. Glauconite is a hydrated silicate of aluminium, iron and potash. The crystalline matters present in fuller’s earth probably include free silica and silicates, together with small amounts of the heavier detrital minerals such as zircon. A considerable amount of calcite may be present in some cases, and various other crystalline products such as barytes and zinc-blende which, though perhaps incorporated in some way during deposition, probably owe their present condition to infiltration and other changes since the fuller’s earth was deposited. The origin of fuller’s earth is not yet understood. Dr. A. H. Cox, who has studied this subject recently on the petrological side, states that, when examined microscopically, fuller’s earth presents certain features that at once distinguish it from ordinary detrital clays, and he is of the opinion that it represents a true precipitate, by which he presumably means a chemical precipitate. He thinks this accounts for its occurrence as an extremely uniform and fine-grained deposit interbedded with coarse sands, and points out that in the occurrences known in this country at different stratigraphical horizons, the fuller’s earth is always associated with sandy limestones or highly calcareous sandstones. On the subject of the origin of fuller’s earth, however, there is much room for difference of opinion, and it seems not improbable that fuller’s earth will be ulti- mately proved to have had a detrital origin for the most part. The possibility should be kept in mind that it may consist of secondary (i.e., redistributed) rather than primary detritus. It might be suggested that the comparison of fuller’s earth chemically, petrologically, and otherwise, 15 with certain other blue clays and muds, including those now being de- posited around our coasts, would prove instructive and would perhaps throw some light on its exact nature and origin. The problems connected with fuller’s earth are attractive and many- sided, and deserve attention as the object of purely scientific research. They are difficult problems, and if they could be solved, the results would undoubtedly be of economic importance. The successful prosecution of such research will require the co-operation of the chemist, the physicist, and petrologist, since it is desirable that the mineralogical and chemical composition, physical properties, and technical uses should all be ascer- tained on each of the samples examined. T. C.