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Vol. 13, No. 4
The Non-Biological Oxidation of Elementary Sulfur in Quartz Media’ [PRELIMINARY REPORT]
By W. H. MacIntire, F. J. Gray and W. M. Shaw UNIVERSITY OF TENNESSEG, AGRICULTURAL EXPERIMENT STATION, KNOXVILI;~, TENNESSEE
T h e conversion of native organic sulfur into sulfates in soils is generally considered t o be a n almost exclusively biological process. The oxidation of added elementary sulfur is likewise usually attributed t o t h e action of bacteria. The native organic sulfur phase of sulfate generation, as influenced b y calcium and magnesium materials in varying amounts, has been under investigation a t t h e University of Tennessee Agricultural Experiment Station since July 1914. At t h a t time, forty-six lysimeters were filled with Cumberland loam, twenty-three tanks having soil alone, a n d twenty-three having surface soil above a 1-ft. layer of clay subsoil. Each annual aggregate of sulfate leachings has been determined quantitatively. Divergent effects of calcium and magnesium compounds upon t h e sulfate outgo during t h e first two years were reported upon in a preliminary paper b y t h e writer and associates.2 T h e supplementary study of sulfur additions t o a Cherokee sandy loam was begun in August 1917. Fifteen tanks received sulfur additions. Each 5-tank group received one of t h e three forms of sulfur: namely, iron sulfate, iron pyrite, a n d flowers of sulfur, each in a n amount equivalent t o 1000 lbs. of sulfur per 2,000,000 lbs. of soil. The question of t h e influence of lime and magnesia upon added sulfur was also included in t h e supplementary study. I n this second installation, comprising twenty-two lysimeters, t h e loss of sulfur, as leached sulfates, was determined for each t a n k periodically, as necessitated by t h e unsupplemented rainfall. The d a t a secured demonstrated t h a t t h e flowers of sulfur and iron pyrite were both converted into sulfates with distinct rapidity. It was a t first assumed t h a t t h e oxidation of both the elementary sulfur and t h a t of t h e pyrites was induced in t h e main, if not solely, by organisms. However, some doubt concerning this assumption was introduced about 2 yrs. after t h e inauguration of t h e experiment, when i t was observed t h a t a strong odor of sulfur dioxide was given off from t h e reserve sample of iron pyrites, which had been kept in t h e dark in a n 8-oz. glass bottle, tightly stoppered with a n ordinary No. 6 cork stopper. A 10-g. charge of t h e pyrites was found t o yield soluble sulfate of iron, equivalent t o a determined weight of 0.4172 g. of BaS04, as an-average of seven determinations. T h e same observation has been reported by Allen a n d Johnston3 in 1910. These workers further reported t h a t a n increase of 100 per cent of sulfate of iron was caused b y grinding for a period of 1 hr. They accounted for t h e reaction b y means of t h e equation: FeSs 302 FeSOc SO2 Contact of moist pulverized metallic iron a n d flowers of sulfur was found t o produce iron sulfide,
+
+
1
Received December 11, 1920.
3
“The Exact Determination of Sulfur in Pyrite and Marcasite,” THIS 2 (1910),196.
* W. 13. McIntire, I,. G. Willis and PI.A. Holding, Soil Sci., 4 (1917),231. JOURNAL,
a reaction which was also found t o be recorded.’ These observations suggested t h e possibility t h a t t h e applied elementary sulfur might combine t o a certain extent with t h e iron of t h e soil, forming compounds which, in turn, would undergo oxidation t o sulfates. It even seemed plausible t o assume t h a t t h e presence of iron might be essential t o t h e extensive conversion of elementary sulfur into sulfates. These observations led t o a laboratory study of t h e two major queries: 1-What function, if any, does metallic iron, and what function does iron oxide, or oxides, have upon the conversion of elementary sulfur to sulfates in soils? 2-Will the effects possibly induced by iron, or its oxides, b e independent of biological activation? EXPERIMENTAL
METHOD
It was planned t o study t h e oxidation of elementary sulfur in t h e absence of appreciable quantities of iron, under aerobic and anaerobic conditions, with t h e unaltered medium, t h e sterilized medium, and t h e medium plus inoculation. The purest obtainable quartz was used E% t h e medium for sulfur additions. An unsuccessful attempt was made to secure a n iron-free quartz. T h e finely ground New England quartzite used r a n 99.28 per cent SiOz, 0.34 per cent Fe203, and 0.0096 per cent S. The purest hydrogen-precipitated iron obtainable (0.0475 per cent sulfur) was used as one source of iron. The other iron compound used was limonite, analyzing 39.50 per cent iron and 0.013 per cent soluble sulfate sulfur. Five hundred-cc. Pyrex flasks were used as containers for t h e treated media. The very finely ground, unleached quartz was used in t h e constant amount. of 250 g., with 14 per cent distilled water additions for moisture. Each medium was kept in t h e dark for a period of 60 days after treatment. I n addition t o t h e constant amount of quartz t h e following single or combined constants were used: 0.1251 g. of sulfur; 10.0806 g. of metallic iron; 25.3164 g. of limonite; 0.5076 g. of C. P. precipitated calcium carbonate; 0.5000 g. of C. P. precipitated magnesium carbonate; 0.5181 g. of 100-mesh limestone; and 0.5449 g. of 100-mesh dolomite. The calcium a n d magnesium materials were chemically equivalent. The biological conditions maintained in t h e original quartz-medium experiments were: 1-Unaltered quartz. 2-Quartz sterilized by heat. 3-Inoculation by soil infusion “A,” &Inoculation by soil infusion “B.” These four conditions were maintained under aerobic and anaerobic conditions. The aerobic flasks, both sterile and nonsterile, were stoppered with cotton plugs. T h e anaerobic atmosphere was produced b y a 6-hr. passage of purified carbon dioxide. 1 S. P. Sadtler and V. Coblentz, “Pharmaceutical and Medicinat Chemistry,” 3rd Ed., Vol. I, 574.
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TABLBI S U M M A RSHOWIXG Y SOLUBLE SULFATESENGENDERED FROM CONTACT OF FLOWERS OF SULFUR WITH POWDERED QUARTZ AND VARIOUS ADDITIONS Sulfate increases expressed as lbs. of S per 2,000,000 lbs. of medium. Uniform rate of sulfur additions, equivalent to 1000 lbs. per 2,000,000 lbs. of medium. Total of 118 distilled water extractions after 60 days of contact -Access t o Atmosphere through Cotton PlugsSealed Atmosphere of CO? Thrice Infusion Infusion Thrice Infusion Infusion Soil Soil Average of Unaltered Sterilized Materials Added to Unaltered Sterilized Soil Soil Average of A B Treatment" Quartz Quartz Quartz Quartz A B 250 G. of Quartz Treatment Sulfur only. 213.1 198.1 241.0 237.7 222.5 243.2 138.3 40.7 167.0 147.3 Sulfur and CaCOa ....................... 623.0 210.9 423.9 505.5 440.8 352.4 ... 154.1 239.3 248.6 Sulfur and limestone. .................... 516.4 192.9 404.9 321 . 9 359 .O 412.0 ... 199.5 228.4 280.0 Sulfur and MgCOa 774.3 142.6 245.4 266.1 357.1 34.4 50.3 143.7 65.0 73.4 Sulfur and dolomite.. 598.4 134.4 410.4 482.6 406.6 379.8 146.4 225.7 182.0 233.5 Average for carbonate group 628.0 170.2 371.2 394.0 390.9 294.7 98.4 180.8 178.7 208.8 Sulfur and F e ........................... 89.0 86.9 68.3 63.9 77.0 -39.9 -37.7 -18.0 -23.5 -29.8 70.5 112.6 123.0 84.7 -27.9 -32.2 Sulfur, CaCOa, and Fe . . . . . . . . . . . . . . . . . . 172.1 -19.1 8.2 -21.9 136.4 78.1 129.5 -39.9 -37.2 -36.6 -22.4 -34.0 Sulfur, limestone, 167.8 170.3 , 154.1 58.5 73.8 91.8 94.6 -42.1 -26.8 -20.2 -16.9 -26.5 169.9 112.1 127.9 104.9 128.7 -29.0 -50.8 -48.6 -27.8 -39.1 Average for iron group . . . . . . . . . . . . . . . . 1 5 0 . 6 110.2 86.6 92.1 109.5 -35.8 -36.9 -28.5 -19.8 -30.3 222.9 657.9 453.6 456.0 280.3 312.6 149.2 134.9 219.3 Sulfur and limonite.. .................... 490.7 383.6 361.7 25.1 110.4 220.2 Sulfur, CaCOa, and limonite.. , . . . . . 5 6 0 . 1 3 1 6 . 8 5 3 9 . 9 6 2 4 . 1 510.2 231.7 594.6 592.4 478.5 334.4 403.2 146.5 Sulfur, limestone, and limonite., . . . . . . . . . 496.1 166.7 262.7 270.0 341.6 356.9 412.4 185.2 145.3 154.6 Sulfur, MgCOs, and limonite.. 680.9 139.9 156.3 186.9 673.8 636.1 519.0 343.7 376.0 154.6 143.1 254.4 Sulfur, dolomite, and limonite.. 579.2 532.6 305.4 319.8 561.2 245.7 561.6 475.2 126.0 139.0 Average for limonite group.. 224.6 Grand average-showing effect of chemical treatment given quartz.. 418.9 177.2 331.1 329.2 314.1 184.7 132.2 92.9 106.1 129.6 277.01 218.61 139.41 157.7' 194.41 f N o t including the less-than-check iron group.
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An additional series containing purified hydrogen was also subjected t o experimental treatment, b u t this series is not yet ready for report. T h e sterilization was effected by three successive daily heatings in t h e autoclave, without contact of quartz, and t h e separately sterilized materials used i n t h e several treatments. T h e sterile added materials were mixed throughout t h e dry sterile quartz immediately before t h e addition of t h e constant moisture content, every care being taken t o insure continued sterility. All of t h e stoppered flasks were p u t away in t h e dark, in a room relatively free from fumes, for a period of 60 days. At t h e end of t h e 60d a y period t h e contents of t h e flasks were extracted by addition of cold distilled water t o near-complete volume. After 4 hrs.' shaking a n d standing over night, t h e extracts ,were filtered with double filters through Biichner funnels. Each residue was then thoroughly mixed and returned t o its original flask for a n additional period of contact of 40 days, after which t h e filtration was repeated. The filtrates were analyzed for sulfides, and, if necessary, sodium hydroxide was introduced. They were t h e n acidified and evaporated, t o dryness, i n order t o remove silica. The engendered sulfates, as well as t h e sulfates of all blanks, were determined gravimetrically. Tests were made t o insure t h e fact t h a t t h e precipitates were not barium fluoride. I n addition t o t h e eight series of fifteen flasks each, a n additional set of twelve flasks was r u n simultaneously. Three flasks contained inoculated quartz a n d nitrate nitrogen t o t h e extent of 10 mg. of nitrogen, one flask containing sodium nitrate, one calcium nitrate, a n d one magnesium nitrate. These three nitrate treatments were duplicated with a n increase of nitrate nitrogen t o a basis of 50 mg. The six flasks above described were then duplicated as t o nitrogen treatment, b u t with t h e addition of 10.0806 g. of metallic iron t o each flask. The details of t h e scheme of treatment and t h e summary of available leaching d a t a are set forth in Tables I and 11. The calcium and magnesium materials were not added upon t h e assumption t h a t they would react directly with t h e sulfur, b u t in order t o pre-
vent t h e possible accumulation of free end-product acids. These d a t a represent t h e summation of a number of tables secured from t h e analysis of leachings after t h e first period of 60 days a n d are corrected b y subtraction of t h e soluble sulfates leached initially from t h e single or combined treatments, as determined upon t h e separate materials. Most of t h e sulfates leached from t h e second 40-day period have been determined a n d will be included in t h e more detailed report t o be published at a n early date. The d a t a are given in pounds of sulfate sulfur, per 2,000,000 lbs. of quartz, recovered from t h e added flowers of sulfur, which was applied in amounts equivalent t o 1000 lbs. of sulfur per 2,000,000 lbs. of quartz. Some further studies involving t h e use of waterleached a n d acid-leached quartz media are also being used for further study of t h e transformations following additions of elementary sulfur. The influence of a combination of metallic iron and limonite is also being studied with regard t o antagonism. It has been found t h a t such a combination evolves considerable amounts of heat. An effort is also being made t o determine whether or not t h e generation of sulfur under t h e conditions maintained would have any effect upon t h e solubility of simultaneously added and intimately mixed rock phosphate. DISCUSSIOK O F R E S U L T S
The d a t a of Table I show a number of consistent and striking relationships. I n t h e case of t h e flasks having limited access t o air, t h e unaltered and untreated quartz shows a gain in sulfate, as do also t h e portions sterilized a n d inoculated. The first group of calcium a n d magnesium supplementary materials, t o be considered, in a sense, as checks, shows a distinct increase in sulfates above t h e gain shown by t h e quartz and sulfur alone, induced directly or indirectly, in t h e three conditions other t h a n sterilized. I n t h e metallic iron group t h e consistent depressive action of iron alone is strikingly demonstrated; while t h e oxidizing tendency of t h e supplementary carbonate materials is shown b y t h e excess of sulfates where these materials are included, as contrasted with t h e iron alone.
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I n t h e third, or limonite, group there is demonstrated a n acceleration in sulfur oxidation, particularly as contrasted with t h e depressive tendency exhibited by t h e metallic iron group. This holds t r u e for limonite alone a n d limonite as supplemented by t h e carbonate materials. On comparing t h e four carbonate-limonite additions with t h e four carbonateonly treatments, i t would seem t h a t both materials are, in part, responsible for t h e general tendency toward increase when t h e combined treatments are made. Although t h e heat-sterilized flasks yielded less sulfur t h a n did t h e unaltered quartz, this fact could not be considered as positively indicating eradication of biological agencies by heat. It is possible t h a t t h e repeated heating may have depressed t h e activation of the materials able t o induce chemical oxidation; for i t will be noted t h a t t h e two inoculations did not increase t h e sulfate yield above t h a t of t h e original unaltered quartz. Then, too, such repeated heati n g ~might be considered as dissipating a part, or t h e whole, of a n y oxidizing atmosphere which may be condensed upon t h e surface of the quartz particles. Considering t h e anaerobic carbon dioxide series, we find certain striking results. T h e elementary sulfur in t h e quartz-sulfur flasks appears t o have utilized oxygen from either t h e carbon dioxide of t h e atmosphere, water, or silica. It appears hardly conceivable t h a t silica could be considered as a source of oxygen for the oxidation phenomenon. However, in the case of t h e carbonate materials, t h e combined carbon dioxide may be considered as possibly having either a direct or indirect influence upon t h e acquisition of oxygen b y t h e elementary sulfur. But, since the distilled water used t o maintain a uniform moist u r e contact was freed of gases by boiling, t h e oxygen could have come from no other sources, unless i t be assumed t h a t appreciable quantities of oxygen or air were condensed upon t h e surface of the quartz particles. This hypothesis would necessarily be predicted upon t h e assumption t h a t such a condensed gas is tenaciously held by physical attraction, b u t is, a t the same time, extensively available chemically for t h e oxidation of t h e added materials under conditions of intimate moist contact. None of t h e treatments leached up t o this point have been tested for an occurrence of free hydrogen, but several have been tested for carbon monoxide. I n one case, a quantitative determination gave 280 mg. of carbon monoxide in t h e absence of limonite.
It appears t h a t the magnesium carbonate has a distinct depressive tendency upon t h e oxidation of sulfur in t h e presence of a n atmosphere of carbon dioxide. T h e cause of this particular phenomenon will not be considered a t this time except t o point t o the ready solubility of MgCO8 in carbonated water. It will be noticed, moreover, t h a t this distinctive depressive action of magnesium carbonate is not obtained in a case of the aerobic group. A study of t h e metallic iron group shows t h a t , in every case of the twenty treatments, we find a posi-
1701. 13, No. 4
tive depression t o t h e extent of being below t h e actual determined blank in each instance. The depression induced by iron was decidedly accentuated in t h e anaerobic atmosphere, as compared with t h e aerial atmosphere, no one treatment of which gave a recovery less t h a n t h e corresponding blanks. It would seem t h a t t h e oxygen available, in whatever form, is more readily attached t o t h e metallic iron t h a n t o t h e elementary sulfur. T h e occurrence of ferric hydrated oxide is readily noted when the contents of the flasks are subjected t o extraction and leaching. Again, in noting t h e sulfate recovered from t h e limonite group, we find t h a t the limonite alone, and when supplemented, is responsible for acceleration in t h e formation of leachable sulfates. I n this group, as in t h e corresponding group under aerobic conditions, i t is difficult t o differentiate quantitatively between t h e results induced by t h e limonite and those induced by t h e carbonate, when t h e combination treatments were made. It is apparent, however, t h a t both t h e mineral carbonates a n d calcium carbonate have t h e accelerative tendency exhibited by limonite in t h e generation of sulfates. Here, again, we note t h e same retarding tendency exhibited by the magnesium carbonate in t h e presence of carbonated water t h a t was manifested in t h e case of the magnesium carbonate treatment alone, under the anaerobic condition. It is rather strikingly demonstrated t h a t t h e presence of limonite tends t o restrict, or offset, t h e depressive influence exhibited b y t h e precipitated magnesium carbonate wherein contact with carbon dioxide was maintained, which was so distinctly recorded in t h e first group of calcium and magnesium materials alone. TABLEII-SHOWING
I N F L U E N C E O F I R O N AND OF N I T R A T E NITROGEN UPON OXIDATION O F ELEMENTARY SULFUR
Added at rate of 1000 lbs per 2 000,000 lbs. of medium. Soil mfusion; COZ atmosphere; 60-day aAd 40-day periods of contact Sulfate Sulfur 1,eached .. . ..- after
Removal of Sulfate Sulfur Nitrate NitroLeached. Lbs. gen. Effected per 2,000,000 by First ExtracMaterials Added to Lbs. of Medium tion4O-Day 250 G of Quartz after Period of 60 Days Contact 40 7 188.1 Sttlfur o n l y . . , , .. . .. . . . , 218.0 Sulfur and 10 mg. N as NaNOa. , . . , 173.7 107.2 132.5 Sulfur and 10 mg. N as Ca(N0a)z.. . 222.4 253 . 0 Sulfur and 10 mg. N as M g ( N 0 3 ) ~ . 186.5 202.5 GroliD average - for 10 me. N. 302.2 12.5 Sulfur and 50 mg. N as NaNOa. 236.0 3.2 Sulfur and 50 mg. N as Ca(N0a)z. . 195.3 4.4 Sulfur and 50 mg. N as M g ( N 0 a ) ~ . . 244,5 6.7 Group average for 50 mg. N . . Sulfur 10 mg N as NaN03 and F e . . . -38.5 18.7 116.4 -35.3 Sulfur’ 10 m g N as Ca(N0a)s ‘and F e . +19.1 -33.3 SulIur: 10 mg: N as Mg(NOs)2 and F e . -+14.7 -35.8 Group average for 10 mg. N and Fe . 4-13 0 -12.5 Sulfur 50 mg. N as NaNOs and F e . . 1-15.3 -30.0 Sulfur‘ 50 mg. N as Ca(N0a)z and F e . . +13.6 -34.4 Sulfur’ 50 mg. N as Mg(N0.z)~and F e . GroLp average for 50 mg. N and F e . -25.6 +14,2
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T h e contents of Table I 1 are from the simultaneous supplementary experiment. I n this particular instance, the three forms of nitrate nitrogen, such as might be found in a normal soil, were introduced along with a n infusion from a soil of known sulfofying capacity. It is consistently shown t h a t t h e presence of added nitrate has an effect upon t h e generation of sulfate. The greater depression induced by the larger amounts
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T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
of t h e oxygen-carrying salts indicates t h a t t h e concentration of salts in t h e moisture of t h e medium is a potent factor in t h e speed, if not ultimate extent, of t h e sulfate formation. It is quite possible t h a t this factor of salt concentration in t h e moisture of t h e medium may account for t h e depressive action exhibited by magnesium carbonate in t h e carbon dioxide atmosphere, as compared with t h e anaerobic condition, since magnesium carbonate is exceedingly soluble in carbonated water. The d a t a relative t o t h e amounts of sulfates leached a f t e r t h e second exposure of 40 days, subsequent t o the removal of both added nitrate and generated sulfates, confirmed t h e point indicated b y t h e results from t h e first contact. Here, again, we find t h e depressive tendency of metallic iron prevailing, though nitrates were present. I t is a rather striking fact t h a t these six determinations added t o t h e corresponding d a t a of Table I give us twenty-six determinations of remarkable consistency relative t o t h e influence of metallic iron upon t h e formation of sulfates. I n every one of t h e twenty-six treatments (excepting t h e one instance of a n increase of b u t 1 . 1 Ibs.), involving additions of metallic iron, t h e recovery is below t h e amount actually determined as being present initially in t h e added materials, singly and in combination. It would appear. also, t h a t not only does t h e metallic iron preempt t h e available oxygen, b u t it also effects a reduction of t h e sulfates originally present as impurities in the several materials. T h e problem of the function of surface in effecting oxidation is one which is also being considered. T h e presence of t h e quartz medium exerts a certain definite increase in t h e end-products, within a definite time, over t h e amounts found where t h e reaction takes place in t h e absence of silica. As a n example, a mixture of quartz, sulfur, and limonite, boiled gently over night with distilled water, gave an increase amounting t o 3 . 2 times t h a t obtained when t h e sulfur and limonite were boiled together without quartz. It is hoped t o remove part, or all, of any condensed atmosphere upon t h e quartz particles and then study t h e oxidation induced thereafter. The fact t h a t we have secured t h e extensive oxidation of sulfur added t o quartz in an atmosphere of hydrogen eliminates t h e assumption t h a t t h e phenomenon is necessarily induced b y t h e oxygen of t h e atmosphere, or t h a t of t h e carbon dioxide gas. It should be made plain t h a t it is not our thesis t o prove t h a t sulfofying organisms are not responsible for transformation of sulfur into sulfates in t h e soil mass. This is particularly true with reference t o native or added organic sulfur materials. Granting t h a t t h e transformation of added elementary sulfur into sulfates may be, in part, a function of t h e biological content of t h e soil, nevertheless, t h e quartzmedium d a t a presented seem t o point very conclusively t o t h e fact t h a t added elementary sulfur may be also readily and extensively transformed into sulfates, by independent chemical action under aerobic a n d anaerobic, sterile and nonsterile conditions of
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moist contact at normal temperature, when ferric oxides and alkali-earth carbonates are present. A detailed report of these and other studies along t h e same lines will be offered shortly, together with some consideration of t h e chemical explanations t o be advanced as accounting for t h e oxidation, with such suggestions as t h e work may carry relative t o other oxidation reactions in t h e soil. Annual Tables of Constants Assembled and published by an International Commission acting under the authority of the International Union of Pure and Applied Chemistry. COXMISSIONERS CH. MARIE(France), General Sec’y PAULDUTOIT(Switzerland) G. CARRARA (Italy) ALFREDEGERTON (England) ERXSTCOHEN(Holland) E. W. WASHBURN (United States)
The publication of the “Annual Tables of Constants and Xumerical Data, Chemical, Physical, and Technological,” which was interrupted during the war, has now been resumed. Subscriptions t o Volume IV, containing all numerical data published during the years 1913 to 1916, inclusive, will be received up to M a y 3 1 a t the special reduced rates indicated below. The edition will be limited, and the price will be raised after May 31.
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Vol. IV is divided into two parts, Part I containing the constants from “Compressibility” t o “Electricity” (see Table of Contents, Vol. 111),and Part I1 the remaining constants. Part I will be delivered probably early in July and Part I1 some months later. Subscribers to both volumes will receive Part I on the July delivery. Subscribers whose payments accompany their subscriptions will receive the volumes carriage free. To others delivery will be made by C. 0 . D. express. Orders for Volumes I, 11, and I11 will be received at $7.20 each. Vol. I is, however, not sold separately, owing to t h e limited supply. Volume V, covering the years 1917 to 1920, inclusive, is in preparation and will be ready for distribution late in 1922. Orders from members of the SOCIETY should include the statement: “I hereby certify that I am a member of the AMERICAX
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The British Dyestuffs Committee In accordance with the provisions of the British Dyestuffs Act of 1920, the following committee has been appointed by the Board of Trade t o advise with respect to the granting of licenses under the Act: VERNONCLAY,Joint Managing Director, Robert Clay, Ltd. GEORGE WELSHCURRIE GEORGEDOUGLAS, Managing Director, Bradford Dyers’ Association, Ltd E. V. EVANS,O.B.E., F I . C . , Treasurer, Society of Chemical Industry MARTINONSLOW FORSTER, F.R.S., F I.C., Director, Salter Institute of Industrial Chemistry C. C. RAILTON, Director, Calico Printers’ Association, Ltd. H. B. SHACKLETON, Messrs. Taylor, Shackleton & Co., Shipley THOMAS TAYLOR, Cornbrook Chemical Co , Stockport S. A. H . WHETMORE, British Dyestuffs Corporation, Ltd. W. J. U. WOOLCOCK, C.E.B , M.P., General Manager, Association British Chemical Manufacturers
Pending the appointment of a permanent chairman, Mr. Percy Ashley, C.B., Assistant Secretary, Industries and Manufactures Dept., Board of Trade, will act as chairman of the committee. The secretary is Mr. W. Graham, RI,B.E.
