Se 4 vey en = “ Fa FR ete > erie peers TU pete! Saeco - JOURNAL OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS BOARD OF EDITORS R. W. Batcom, Chairman R. E. Doo.uirrLe C. B. Lipman E. F. Lapp WILuiAM FREAR N. A. Pargrnson,. Associate Editor VOLUME IV 1920-21 1921 ft ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS , gy © BOX 290, PENNSYLVANIA AVENUE STATION, D WASHINGTON, D. CG. \VA\ Copyricut, 1921, BY Tue AssocrIATION OF OFFICIAL AGRICULTURAL CHEMISTS ERRATA. Page 158, paragraph 3, line 3.—After “‘(dry basis)’’ add ‘‘and Canadian lead number, respectively”’. Page 158, heading for Table 2.—Change ‘‘total ash (dry basis)’’ to “Canadian lead number’. Page 314, paragraph 4: Lines 3 and 8.—Change “‘1924 pounds”’ to “2924 pounds’. Line 9.—Change “710 pounds”’ to ‘1079 pounds’’. Line 11.—Change “112 pounds’”’ to “170 pounds’”’. Page 316, line 2.—Change ‘‘40 acres’’ to “30 acres’. Page 317, paragraph 4, lines 3 and 4.—Change “sixtieth”’ to “‘both’’. Page 337, line 5.—Change ‘‘(3)”” to “‘(4)”’ and transfer with text follow- ing to appropriate position for “‘(4)’’. Page 337, line 6—Change ‘‘(4)”’ to “(3)’’ and transfer with text follow- ing to appropriate position for “*(3)”’. Page 340, footnote 1—Change ‘‘3’’ to ‘‘4’’. Page 366, footnote 2.—Change ‘‘16’’ to ‘‘56”’. Page 452, footnote 2.—Change ‘‘8’’ to ‘51’. S 583 CONTENTS PROCEEDINGS OF THE THIRTY-FOURTH ANNUAL CONVENTION, NOVEMBER, 1917. PAGE Officers, Referees, Associate Referees and Committees of the Association of Official Agricultural Chemists, for the Two Years Ending November, 1919.......... Members and Visitors Present, 1917 Meeting. ................0. cece eee eee 5 President.spaddresss sy) Japs EaywOOd eran ere i.e). mrcicrs rerio eirocienia eso test 11 Monpay—MorninG SESSION. Report on Crude Fiber. By G. K. Francis..............--22 2222222 eee eee 39 Report on Stock Feed Adulteration. By B. H. Silberberg..........-......-.-- 41 Report on Water in Foods and Feeding Stuffs. By J. O. Clarke. ............... 48 A New Method for Moisture Determination. By G. F. Lipscomb and W. D. Taher A eS OS SG RIOR. A. Gonicle DAS ea Came en Oita at acnio Double Moisture Determinations in Fertilizer Materials. By J. O. Clarke....... 57 Report on Testing Chemical Reagents. By C. O. Ewing...............-...--- 59 Report on Microanalytical Methods. By B. J. Howard...........-...---+.+--- 60 Monpay—AFTERNOON SESSION. The Effect of Mass and Degree of Fineness on the Percentage of Available Phos- phoric Acid in Precipitated Phosphate. By H. D. Haskins................ 64 Report on Nitrogen. By H. D. Haskins and I. K. Phelps. ...............-..-. 66 Report on the Study of the Effect of Glass Wool in the Ferrous Sulphate-Zinc- SedanViethod for Nitrates. (By. K=-Phelpse ic acccceos acess sees er 69 The Use ot Permanganate in the Kjeldahl Method Modified for Nitrates. By I. K. Q GL Steps ere ere neler MM on ob oie iets salle thcisie Pura ctete lle asecveia re aes 9 Investigation of the Kjeldahl Method for Determining Nitrogen. By I. K. Bhelpsand alten Wig SOGU ty St sete eet eee cc cl = 3 sic-2, =) te ois, sre, Ne vd aloe, Saretovete vats 72 ee port onl Potash =e Bye. Arcelie mink clei na tee ie rae tomes sioteless siete ele 76 A Modified Method for the Determination of Water-Soluble Potash in Wood AWehesiand Treater Dusta yb. DS Masking: 2 )j25.e0- ess s.c2c acs ene s ss 82 PREPOLOMVVALELS. ES Vio NW OBIE Sa ears loles oSiele fe ouarcisjeusiestrencusinys cieetoivacke’s ei clesaveu nate 84 Technique of Determination of Soil Phosphorus. By H. A. Noyes: ............- 93 Delemomelon of Moisture in Field Samples of Soil. By H. A. Noyes and J. F. ORG ee eT e yr eateecee aie he ey crete eee ge erase alisrs, b wisielin etataueltey o's exalts 95 A Study in Soil Sampling. By William Frear and E. 8. Erb..................- 98 Excavation Method for Determining the Apparent Specific Gravity of Soils. By Walliamgh rears Anan ey os) BIE ces cycspege lets ner ereat cis orem oheiateta ete Deas cayenne 103 Nitrogenous Compounds in Soils. By J. K. Plammer..................2.2+--- 106 Report on the Lime Requirement of Soils. By W.H. MacIntire............... 108 Determination of Calcium in the Presence of Phosphates. By J. F. Breazeale.... 124 Report on Insecticides and Fungicides. By O. B. Winter..............-.....-- 134 Re portions Drugs (By WO BIMeny cic = scene ccs oie cefecaine cas eds ce rie © 148 Report on Medicinal Plants. By Arno Viehoever.................00ceeeeeeees 149 reportonyAlKalords., eB yobie CreBuller sess conn occ eee ate ge sis sce te sings eyes 156 TuespAyY—MorNinG SEssIoN. Eveport.on: Maple Products. (Bsyds We omell sone chs sce heer mous iets oi nacho ors, 9 aceon es 157 eportion Honey.. By Sidney Ha Sherwood .. . 22). chen soe ae eee eee 272 Presentationof Gavel: sBycR2 NoBrackett5,:.2) 920-6 ee eee eee 273 WEDNESDAY—AFTERNOON SESSION. Report of Committee to Cooperate with Other Committees on Food Definitions. By William: Brear «1. (5 och0 cit vd Bh SR oe Shae Gollims. .. 2). 2 nn. oun ee sige ee eee 454 Physico-Chemical Methods for Determining the Grade of Flour. By C. H. Bailey. 456 Reporuonsy wines mvs Vig tumbler tc: city pacers sa. oO siaate ence sees Geaals oa 459 TuESDAY—AFTERNOON SESSION. Report on Distilled hiquors.~ By. J. Te Palmiores w/o. cc cocci. 0c ices ee tees ewes 465 LeEpontOUAVANe ATS wes N) WPA IEeHOeD ean. aie cleeee dese coinicc. Namlee oe Sheers 466 Reportion!Hlavorng;Eixtractsy. (ByyAG i. Paull 3.9. s..bk < debe jac nc dew o's wera 468 Errors in Gravimetric Vanillin Determinations in Vanilla Extracts. By H. J. \WIGNTABTT PR eee One g Gibco 6 De Oeie Cha RICE eT ERE CIO r re ena ine 479 Reponwon Dairy: Products. By dws Hortvet. «occa .5 cake cc cnee isle acta cenies 482 The Cryoscopic Examination of Milk. By Julius Hortvet..................... 491 Report on Meat and Meat Products. By Ralph Hoagland.................... 499 Report on the Separation of Nitrogenous Compounds in Meat Products. By L. Recep WUT EG INCH Tete ee stereo acs I gst Me we Staricha eyes lajnv states nto eels Mivisteas 502 ReportioniMest Boxtracts. (By Co Re Moulton. .-c)-08 ccc. one nceee eos cece 506 Report on Eggs and Egg Products. By CG. BE. Marsh.....................-.+-- 507 Discussion of Report of Referee on Egg Products. By H. W. Redfield.......... 516 renortion) Gelatin’ — ByiGs ReiSmith sees te hoseaeeicc teens Swen eau 520 report onjEdible Bats;and Oils:s By Ri Kerra: ae) gee soee toes ce el en 523 RERGnBONSpICeES =a By Liebe oindalle. 0-02 seted acerca es ere eo 524 eponuont Cotes... UByib-cAe Tepper... ccso enue rae eee ee ecaare 526 Remunmonwhens bye bs Mia bailey Ne. 8c: boss than oe ae ec ete 534 RepontomBaking Powder. By H.E: Patten... 2.056. .s0 bac ce ec nevees 538 WEDNEsSDAY—MorNING SESSION. Report of the Committee on Editing Methods of Analysis. By R. E. Doolittle... 540 Report of Special Committee on the Baumé Scale. By R. E. Doolittle.......... 551 vi CONTENTS PAGE Report of Secretary-Treasurer for the Two Years Ending November 19, 1919. By GT, Alsberg.. 40: 0... saa. vs <3 552 Report of the Board of Editors. By C. L. Alsberg.....................0--200- 554 Report on Form of Report and Recommendations by Referees. By W. W. Skin- 11) eee IS Sin on Sais a Scie dic cibchalece peece CASS coe cele eee eae CE eee 560 Report of Committee on Recommendations of Referees. By B. B. Ross......... 561 Report of Committee A on Recommendations of Referees. By A. J. Patten... .. 562 Report of Committee B on Recommendations of Referees. By H. C. Lythgoe... 567 Report of Committee C on Recommendations of Referees. By R. E. Doolittle... 575 WEDNESDAY—AFTERNOON SESSION. Report of Committee to Cooperate With Other Committees on Food Definitions. By Wallan (Brean so 3.4.4 502 hae Ac alan sigs aed dee Sa elt es ie ene 586 Report of Committee on Methods of Sampling Fertilizers to Cooperate with a Similar Committee of the American Chemical Society. By C. H. Jones.... 594 A Trial with Two Types of Fertilizer Samplers. By L. D. Haigh............... 597 The Determination of Borax in Fertilizer Materials and Mixed Fertilizers. By G: BE. Lipseomb; Cl ER. Inmantand JS: Watkins. 5.2.72 6. cnee heer eee 599 Report of Committee on Resolutions. By H. B. McDonnell................... 602 Obituary on Albert Frederick Seeker. By R. E. Doolittle and P. B. Dunbar.... 602 Index to’ Volame EVs: Hoa sek Sao tier esta tere ete hse esern ae eC ome eee te 605 PROCEEDINGS OF THE THIRTY-FOURTH ANNUAL CONVENTION OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS, 1917. OFFICERS, REFEREES, ASSOCIATE REFEREES AND COM- MITTEES OF THE ASSOCIATION OF OFFICIAL AGRI- CULTURAL CHEMISTS, FOR THE TWO YEARS ENDING NOVEMBER, 1919. Honorary President. H. W. Witey, Woodward Building, Washington, D. C. President. P. F. Trowsrince, Agricultural Experiment Station, Agricultural College, N. Dak. Vice-President. H. C. Lytucoer, State Department of Health, Boston, Mass. Secretary-Treasurer. C. L. AtsBerG, Box 744, 11th Street Station, Washington, D. C. Additional Members of the Executive Committee. B. B. Ross, Polytechnic Institute, Auburn, Ala. G. G. Frary, State Food and Drug Department, Vermilion, S. Dak. Referees. Phosphoric acid: (Not appointed.) Nitrogen: 1. K. Phelps, Bureau of Chemistry, Washington, D. C. Potash: T. E. Keitt, Agricultural Experiment Station, Ga. Soils: C. B. Lipman, University of California, Berkeley, Calif. Inorganic plant constituents: J. H. Mitchell, Clemson Agricultural College, Clemson College, S. C. Insecticides and fungicides: O. B. Winter, Agricultural Experiment Station, E. Lansing, Mich. Water: J. W. Sale, Bureau of Chemistry, Washington, D. C. Foods and feeding stuffs: G. L. Bidwell, Bureau of Chemistry, Washington, D. C. Dairy producis: Julius Hortyet, State Dairy and Food Department, Old Capitol, St. Paul, Minn. Saccharine products: W.L. Owen, Penick & Ford, Ltd., New Orleans, La. Drugs: G. W. Hoover, U. S. Food and Drug Inspection Station, Transportation Build- ing, Chicago, Ill. 1 2 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Testing chemical reagents: L. F. Kebler, Bureau of Chemistry, Washington, D. C. Microanalytical methods: B. J. Howard, Bureau of Chemistry, Washington, D. C. Food preservatives: A. F. Seeker, U. S. Food and Drug Inspection Station, U. S. Ap- praiser’s Stores, New York, N. Y. (Since deceased.) Coloring matters in foods: W.E. Mathewson, Bureau of Chemistry, Washington, D. C. Metals in foods: W. D. Collins, Bureau of Chemistry, Washington, D. C. Fruits and fruit products: D. B. Bisbee, U. S. Food and Drug Inspection Station, Old Custom House, St. Louis, Mo. Canned vegetables: W. D. Bigelow, National Canners Association, 1739 H Street, N. W., Washington, D. C. Cereal foods: J. A. LeClerc, Miner-Hillard Milling Co., Wilkes-Barre, Pa. Wines: J. M. Humble, U. S. Food and Drug Inspection Station, U. S. Custom House, Cincinnati, Ohio. Soft drinks (bottlers’ products): W. W. Skinner, Bureau of Chemistry, Washington, D. C. Distilled liquors: J. 1. Palmore, Bureau of Chemistry, Washington, D. C. Beers: (Not appointed.) Vinegars: W. A. Bender, Douglas Packing Company, Rochester, N. Y. Flavoring extracts: A. E. Paul, U.S. Food and Drug Inspection Station, Transportation Building, Chicago, Ill. Meat and meat products: Ralph Hoagland, Bureau of Animal Industry, Washington, DAG: Eggs and egg products: C. E. Marsh, State Department of Health, Boston, Mass. Gelatin: C. R. Smith, Bureau of Chemistry, Washington, D. C. Edible fats and oils: R. H. Kerr, Bureau of Animal Industry, Washington, D. C. Spices and other condiments: H. E. Sindall, Austin, Nichols & Co., Inc., New York, N.Y. Cacao products: Leicester Patton, U. S. Food and Drug Inspection Station, Federal Building, Buffalo, N. Y. Coffee: H. A. Lepper, Bureau of Chemistry, Washington, D. C. Tea: E. M. Bailey, Agricultural Experiment Station, New Haven, Conn. Baking powder: H. E. Patten, Provident Chemical Works, St. Louis, Mo. Associate Referees. Phosphoric acid: Basic slag, to cooperate with committee on vegetation tests on the availability of phosphoric acid in basic slag: (Not appointed.) Nitrogen: Special study of the Kjeldahl method: H. W. Daudt, Jackson Laboratory, E. I. Du Pont Company, Wilmington, Del. Potash: (Not appointed.) Soils: Nitrogenous compounds: (Not appointed.) Lime absorption coefficient: W. H. McIntire, Agricultural Experiment Station, Knoxville, Tenn. Inorganic plant constituents: W. L. Latshaw, State Agricultural College, Manhattan, Kans. Insecticides and fungicides: J. J. T. Graham, Bureau of Chemistry, Washington, D. C. Water: L. H. Enslow, Miraflores Filtration Plant, Ancon, Panama, C. Z. 1920| OFFICERS, REFEREES, ASSOCIATE REFEREES AND COMMITTEES 3 Foods and feeding stuffs: Sugar: A. H. Bryan, Arbuckle Bros., Old Slip and Water Streets, New York, N. Y. (Since deceased.) Crude fiber: L. D. Haigh, University of Missouri, Columbia, Mo. Stock feed adulteration: Miss B. H. Silberberg, Bureau of Chemistry, Washing- ton, D. C. Organic and inorganic phosphorus: J. B. Rather, Standard Oil Company, Chem- ical Laboratory, Brooklyn, N. Y. Water: J. O. Clarke, U. S. Food and Drug Inspection Station, Old Custom House, Savannah, Ga. Dairy products: Separation of nitrogenous substances in milk and cheese: L. L. Van Slyke, Agri- cultural Experiment Station, Geneva, N. Y. Saccharine products: Maple products: J. F. Snell, Macdonald College, Quebec, Canada. Honey: (Not appointed.) Sugar house products: F. W. Zerban', Sugar Experiment Station, New Orleans, La.; W. O. Whaley?, Penick & Ford, Ltd., New Orleans, La.; D. D. Sullivant?, Penick & Ford, Ltd., New Orleans, La. Drugs: Medicinal plants: Arno Viehoever, Bureau of Chemistry, Washington, D. C. Alkaloids: A. R. Bliss, jr., School of Medicine, Emory University, Atlanta, Ga. Synthetic products: C. D. Wright, Bureau of Chemistry, Washington, D. C. Balsams and gum resins: E. H. Grant, Wm. S. Merrell Co., Cincinnati, Ohio. Enzyms: J. F. Brewster, Bureau of Chemistry, Washington, D. C. Fruits and fruit products: H. J. Wichmann, U. S. Food and Drug Inspection Station, Tabor Opera House Building, Denver, Colo. Meat and meat products: Separation of nitrogenous compounds in meat products: Walter Ritchie!, Uni- versity of Missouri, Columbia, Mo. L. C. Mitchell’, Wilson & Co., Chemical Laboratory, Chicago, Il. Meat extracts: H. H. Mitchell', University of Illinois, Urbana, Il. C. R. Moulton’, University of Missouri, Columbia, Mo. PERMANENT COMMITTEES. Cooperation with Other Committees on Food Definitions. William Frear (State College, Pa.), Chairman. Julius Hortvet, St. Paul, Minn. C. D. Howard, Concord, N. H. Recommendations of Referees. (Figures in paréntheses refer to year in which appointment expires.) B. B. Ross (Auburn, Ala.), Chairman. Suscommitree A: A. J. Patten (1918), (Agricultural Experiment Station, E. Lansing, Mich.), Chairman, C. C. McDonnell (1922), B. B. Ross (1920). [Phosphoric acid 1 Associate referee for the year ending November, 1918. 2 The work on sugar house products for the year ending November, 1919, was divided between W. O. Whaley and D. D. Sullivant. ? Associate Referee for the year ending November, 1919. 4 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 (basic slag, to cooperate with committee on vegetation tests on the availability of phosphoric acid in basic slag), nitrogen (special study of the Kjeldahl method), potash, soils (nitrogenous compounds, lime absorption coefficient), inorganic plant constituents, insecticides and fungicides, and water.] SuspcomMitrEE B: H. C. Lythgoe (1920), (State Department of Health, Boston, Mass.), Chairman, J. M. Bartlett (1918), C. A. Browne (1922). [Foods and feeding stuffs (sugar, crude fiber, stock feed adulteration, organic and inorganic phosphorus, water), dairy products (separation of nitrogenous substances in milk and cheese), saccharine products (maple products, honey, sugar house products), drugs (me- dicinal plants, alkaloids, synthetic products, balsams and gum resins, enzyms), testing of chemical reagents, and microanalytical methods.] SuscomMitrEE C: R. E. Doolittle (1920), (Transportation Building, Chicago, IIl.), Chairman, W. W. Randall (1918), J. P. Street (1922). [Food preservatives, color- ing matters in foods, metals in foods, fruits and fruit products, canned vegetables, cereal foods, wines, soft drinks (bottlers’ products), distilled liquors, beers, vinegars, flavoring extracts, meat and meat products, (separation of nitrogenous com- ’ pounds in meat products, meat extracts), eggs and egg products, gelatin, edible fats and oils, spices and other condiments, cacao products, coffee, tea, baking powder. } Board of Editors. C. L. Alsberg (Box 744, 11th Street Station, Washington, D. C.), Chairman. C. B. Lipman (1918). L. L. Van Slyke (1920). R. E. Doolittle (1919). E. F. Ladd (1921). SPECIAL COMMITTEES. Editing Methods of Analysis. R. E. Doolittle (Transportation Building, Chicago, Ill.), Chairman. B. L. Hartwell. A. J. Patten. G. W. Hoover. A. F. Seeker (Since deceased). W. A. Withers. Vegetation Tests on the Availability of Phosphoric Acid in Basic Slag. C. B. Williams (College of Agriculture and Mechanic Arts, W. Raleigh, N. C.), Chairman. J. A. Bizzell. H. D. Haskins. B. L. Hartwell. C. G. Hopkins. Committee on Methods of Sampling Fertilizers to Cooperate with a Similar Committee of the American Chemical Society. C. H. Jones (Agricultural Experiment Station, Burlington, Vt.), Chairman. E. G. Proulx. B. F. Robertson. Committee on Revision of Methods of Soil Analysis. C. B. Lipman (University of California, Berkeley, Calif.), Chairman A.W. Blair. E. C. Shorey. W. H. McIntire. R. Stewart. 1920| MEMBERS AND VISITORS PRESENT, 1917 MEETING 5 MEMBERS AND VISITORS PRESENT, 1917 MEETING. Albrech, M. C., The R. T. French Company, Rochester, N. Y. Allison, F. E., Bureau of Markets, Washington, D. C. Almy, L. H., 1833 Chestnut Street, Philadelphia, Pa. Alsberg, C. L., Bureau of Chemistry, Washington, D. C. Anderson, M. S., Bureau of Soils, Washington, D. C. Appleman, C. O., State College of Agriculture, College Park, Md. Atkinson, F. C., American Hominy Co., Indianapolis, Ind. Bailey, C. H., University Farm, St. Paul, Minn. Bailey, H. S., Southern Cotton Oil Company, Savannah, Ga. Bailey, L. H., Bureau of Chemistry, Washington, D. C. Balch, R. T., Bureau of Chemistry, Washington, D. C. Bartlett, G. M., Joseph Campbell Co., Camden, N. J. Bartlett, J. M., Agricultural Experiment Station, Orono, Me. Baston, G. H., Bureau of Markets, Washington, D. C. Bates, Frederick, Bureau of Standards, Washington, D. C. Baughman, W. F., Bureau of Chemistry, Washington, D. C. Beal, W. H., States Relations Service, Washington, D. C. Bennett, Miss B. M., States Relations Service, Washington, D. C. Bidwell, G. L., Bureau of Chemistry, Washington, D. C. Bigelow, W. D., National Canners Association, 1739 H Street, N. W., Washington, D.C. Blair, A. W., Agricultural Experiment Station, New Brunswick, N. J. Blanck, F. C., National Canners Association, Easton, Md. Bohart, G. H., National Canners Association, 1739 H Street, N. W., Washington, D. C. Bohn, R. M., Advance Malt Products Co., 305 South La Salle Street, Chicago, Ill. Borden, N. H., Sherwin-Williams Co., Chicago, Il. Boyle, Martin, Bureau of Chemistry, Washington, D. C. Boyles, F. M., McCormick & Co., Baltimore, Md. Brackett, R. N., Clemson Agricultural College, Clemson College, S. C. Bradbury, C. M., Department of Agriculture and Immigration, Richmond, Va. Bradley, L. W., State Department of Agriculture, Atlanta, Ga. Brattain, P. H., Corby Co., Langdon, D. C. Breckenridge, J. E., American Agricultural Chemical Co., Carteret, N. J. Brewster, J. F., Bureau of Chemistry, Washington, D. C. Broughton, L. B., State College of Agriculture, College Park, Md. Brown, B. E., Bureau of Plant Industry, Washington, D. C. Brown, H. H., Pegepscot Paper Co., Brunswick, Me. Browne, C. A., New York Sugar Trade Laboratory, 80 South Street, New York, N. Y. Buckner, G. D., Agricultural Experiment Station, Lexington, Ky. Campbell, V. H., Gibbs Preserving Co., Baltimore, Md. Carothers, J. N., Bureau of Soils, Washington, D. C. Cathcart, C. S., Agricultural Experiment Station, New Brunswick, N. J. Charron, A. T., Official Provincial Laboratory, St. Hyacinthe, Canada. Chesnut, V. K., Bureau of Chemistry, Washington, D. C. Churchill, J. B., 80 South Street, New York, N. Y. Clarke, W. F., Bureau of Chemistry, Washington, D.C. Clay, C. L., State Board of Health, New Orleans, La. Coleman, D. H., Bureau of Markets, Washington, D. C. 6 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Collins, W. D., Geological Survey, Washington, D. C. Cook, F. C., Bureau of Chemistry, Washington, D. C. Craig, R. S., City Health Department, Baltimore, Md. Custis, H. H., Bureau of Animal Industry, Washington, D. C. Daudt, H. W., Jackson Laboratory, E. I. Du Pont Co., Wilmington, Del. Dayidson, J., Bureau of Chemistry, Washington, D.C. Davis, R. A., Post Office Department, Washington, D. C. DeBord, G. G., Department of Medicine and Hygiene, Harvard Medical School, Boston, Mass Deuel, H. J.. Home Economic Laboratory, White Bear Lake, Minn. Doolittle, R. E., Transportation Building, Chicago, IIl. Doyle, Miss A. M., 1365 Oak Street, N. W., Washington, D. C. Dubois, W. L., Berlin Arcade Building, Milwaukee, Wis. Du Mez, A. G., Hygienic Laboratory, Washington, D. C. Dunbar, P. B., Bureau of Chemistry, Washington, D. C. Dyer, D. A., Bureau of Animal Industry, Washington, D. C. Edmonds, J., Davison Chemical Co., Baltimore, Md. Eimer, W. R., 205 Third Avenue, New York, N. Y. Ellett, W. B., Agricultural Experiment Station, Blacksburg, Va. Emery, W. O., Bureau of Chemistry, Washington, D. C. Emmons, F. W., Washburn-Crosby Co., Minneapolis, Minn. Enslow, L. H., Miraflores Filtration Plant, Ancon, Panama, C. Z. Ewing, C. O., United Drug Company, Boston, Mass. Fellers, C. R., Sanitary Inspector, New Brunswick, N. J. Ferris, L. W., Bureau of Chemistry, Washington, D. C. Fitzgerald, F. F., National Canners Association, 1739 H Street, N. W., Washington, D. C. Flint, E. R., States Relations Service, Washington, D. C. Frary, G. G., State Food and Drug Commission, Vermilion, S. Dak. Frear, William, Agricultural Experiment Station, State College, Pa. French, D. M., Alexandria Fertilizer & Chemical Co., Alexandria, Va. Frisbie, W. S., State Department of Agriculture, Lincoln, Nebr. Fry, W. H., Bureau of Soils, Washington, D. C. Fuller, A. V., Bureau of Animal Industry, Washington, D. C. Fuller, H. C., Institute of Industrial Research, Washington, D. C. Furber, F. B., Lederle Laboratories, New York, N. Y. Garby, C. D., Bureau of Chemistry, Washington, D. C. Gardiner, R. F., Bureau of Soils, Washington, D. C. Gascoyne, W. J., Gascoyne & Co., Inc., Baltimore, Md. Geagley, W. C., State Food and Drug Department, Lansing, Mich. Geidel, C. D., State Dairy and Food Department, Old Capitol, St. Paul, Minn. Gillespie, L. J., Bureau of Plant Industry, Washington, D. C. Goodrich, C. E., Bureau of Chemistry, Washington, D. C. Gordon, W. O., Industrial Appliance Co., Chicago, Ill. Gowen, P. L., National Canners Association, Easton, Md. Grab, E. G., National Fruit Product Co., Washington, D. C. Graham, J. J. T., Bureau of Chemistry, Washington, D. C. Grant, D. H., Bureau of Chemistry, Washington, D. C. 1920) MEMBERS AND VISITORS PRESENT, 1917 MEETING 7 Grant, E. H., Wm. S. Merrell Co., Cincinnati, Ohio. Gray, M. A., Chemist, Minneapolis, Minn. Griffin, E. L., Bureau of Chemistry, Washington, D. C. Hand, W. F., Agricultural and Mechanical College, Agricultural College, Miss. Harris, H. L., Pacific Coast Borax Co., 100 William Street, New York, N. Y. Hart, B. R., 530 St. Paul Street, Baltimore, Md. Hartwell, B. L., Agricultural Experiment Station, Kingston, R. I. Haskins, H. D., Agricultural Experiment Station, Amherst, Mass. Haywood, J. K., Bureau of Chemistry, Washington, D. C. Hazard, I. W., Red Wing Preserving Co., Fredonia, N. Y. Hazen, William, Bureau of Soils, Washington, D. C. Heath, W. H., Bureau of Chemistry, Washington, D. C. Hellmuth, E. A., National Canners Association, 1739 H Street, N. W., Washington, D. C. Hoagland, D. R., Agricultural Experiment Station, Berkeley, Calif. Holmes, A. D., Jackson Laboratory, E. I. Du Pont Co., Wilmington, Del. Hoover, G. W., U. S. Food and Drug Inspection Station, Transportation Building, Chicago, Il. Hortvet, Julius, State Dairy and Food Department, St. Paul, Minn. Houghton, H. W., Hygienic Laboratory, Washington, D. C. Howes, C. C., Davison Chemical Co., Baltimore, Md. Hoyt, C. F., 318 Federal Building, Salt Lake City, Utah. Hubbard, W.S., U.S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, New York, N. Y. Hurst, L. A. Bureau of Plant Industry, Washington, D. C. Huston, H. A., 42 Broadway, New York, N. Y. Ingle, M. J., Albion, N. Y. Irwin, W. H., Swift & Co., Chicago, Il. Irwin, Mrs. W. H., Swift & Co., Chicago, Ill. Jackson, R. F., Bureau of Standards, Washington, D. C. Jacobs, B. R., Bureau of Chemistry, Washington, D. C. Jamieson, G. S., Bureau of Chemistry, Washington, D. C. Jarrell, T. D., Bureau of Chemistry, Washington, D. C. Johns, C. O., Bureau of Chemistry, Washington, D. C. Johnson, J. M., Hygienic Laboratory, Washington, D. C. Jones, C. H., Agricultural Experiment Station, Burlington, Vt. Jones, W. P., Union Trust Building. Washington, D. C. Kebler, L. F., Bureau of Chemistry, Washington, D. C. Keenan, G. L., Bureau of Chemistry, Washington, D. C. Keister, J. T., Bureau of Chemistry, Washington, D. C. Kellogg, J. W., State Department of Agriculture, Harrisburg, Pa. Klein, David, Hollister-Wilson Laboratories, Chicago, Il. Knight, H. L., States Relations Service, Washington, D. C. Knight, O. D., Insecticide and Fungicide Board, Washington, D. C. Krazbill, H. R., Bureau of Plant Industry, Washington, D. C. Kunke, W. F., Bureau of Chemistry, Washington, D. C. 8 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Langenbeck, Karl, Agricultural Lime Bureau of the National Lime Manufacturers, Washington, D. C. Lathrop, E. C., 8096 Du Pont Building, Wilmington, Del. LeClerc, J. A., Miner-Hillard Milling Co., Wilkes-Barre, Pa. LeCompte, T. R., Bureau of Soils, Washington, D. C. Lepper, H. A., Bureau of Chemistry, Washington, D. C. Lewis, H. F., University of Maine, Orono, Me. Linder, W. V., Bureau of Internal Revenue, Washington, D. C. Lipman, C. B., University of California, Berkeley, Calif. Lodge, F. S., Armour Fertilizer Works, Chicago, Ill. Lynch, W. D., Bureau of Chemistry, Washington, D. C. Lyons, Mrs. M. A., Bureau of Chemistry, Washington, D. C. (Since deceased.) Lythgoe, H. C., State Department of Health, Boston, Mass. McCall, A. G., Agricultural Experiment Station, College Park, Md. McDonnell, C. C., Bureau of Chemistry, Washington, D. C. McDonnell, H. B., Agricultural Experiment Station, College Park, Md. McGeorge, W. T., U. S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, San Francisco, Calif. McIntire, W. H., Agricultural Experiment Station, Knoxville, Tenn. Magnuson, H. P., Bureau of Soils, State Farm, Lincoln, Nebr. Magruder, E. W., F. S. Royster Guano Co., Norfolk, Va. Makemson, W. K., Bureau of Markets, New York, N. Y. Mallory, G. M., Bureau of Internal Revenue, Washington, D. C. Mason, G. F., H. J. Heinz Co., Pittsburgh, Pa. Mathewson, W. E., Bureau of Chemistry, Washington, D. C. Menge, G. A., Hires Condensed Milk Co., 913 Arch Street, Philadelphia, Pa. Middleton, E. S., National Canners Association, 1739 H Street, N. W., Washington, DG: Miller, C. F., Bureau of Soils, Washington, D. C. Miller, H. M., National Canners Association, Los Angeles, Calif. Mitchell, A. S., Bureau of Chemistry, Washington, D. C. Monarch, J. L., Bureau of Chemistry, Washington, D. C. Morgan, W. J., Bureau of Chemistry, Washington, D. C. Mory, A. V. H., N. K. Fairbanks Co., Cincinnati, Ohio. Monch, J. C., Bureau of Chemistry, Washington, D. C. Nealon, E. J., Bureau of Chemistry, Washington, D. C. Nelson, E. K., Bureau of Chemistry, Washington, D. C. Nollau, E. H., E. I. Du Pont Co., Wilmington, Del. Oberhelman, G. O., Bureau of Chemistry, Washington, D. C. O'Neill, A. T., State College of Agriculture, College Park, Md. Palkin, Samuel, Bureau of Chemistry, Washington, D. C. Palmer, H. E., Bureau of Chemistry, Washington, D. C. (Since deceased.) Palmore, J. I., Bureau of Chemistry, Washington, D. C. Parkins, J. H., F. S. Royster Guano Co., Norfolk, Va. Parkinson, Miss N. A., Bureau of Chemistry, Washington, D. C. Patten, A. J., Agricultural Experiment Station, E. Lansing, Mich. Patten, H. E., Bureau of Chemistry, Washington, D. C. 1920} MEMBERS AND VISITORS PRESENT, 1917 MEETING 9 Patterson, H. J., Agricultural Experiment Station, College Park, Md. Phelps, F. P., Bureau of Standards, Washington, D. C. Phelps, I. K., Bureau of Chemistry, Washington, D. C. Pingree, M. H., American Agricultural Chemical Co., Baltimore, Md. Pope, W. B., 1416 Newton Street, N. W., Washington, D. C. Powdermaker, Miss Florence, States Relations Service, Washington, D. C. Pozen, M. A., Health Department, Washington, D. C. Price, T. M., 1811 Irving Street, Washington, D. C. Proulx, E. G., Agricultural Experiment Station, La Fayette, Ind. Pulizzi, T. O., Bureau of Chemistry, Washington, D. C. Quaintance, C. F., Coors Porcelain Co., Golden, Colo. Rabak, Frank, Bureau of Plant Industry, Washington, D. C. Randall, W. W., State Department of Health, 16 W. Saratoga Street, Baltimore, Md. Rask, O. S., Bureau of Chemistry, Washington, D. C. Rather, J. B., Agricultural Experiment Station, Fayetteville, Ark. Read, Miss E. A., Bureau of Chemistry, Washington, D. C. Redfield, H. W., U. S. Food and Drug Inspection Station, U.S. Appraiser’s Stores, New York, N. Y. Reed, J. B., Bureau of Chemistry, Washington, D. C. Remington, R. E., Agricultural Experiment Station, Fargo, N. Dak. Remsburg, C. G., State College of Agriculture, College Park, Md. Roark, R. C., General Chemical Company, Baltimore Works, Baltimore, Md. Robb, J. B., State Department of Agriculture, Richmond, Va. Roberts, O. S., Agricultural Experiment Station, La Fayette, Ind. Robinson, C. H., Dominion Experimental Farms, Ottawa, Canada. Rodes, William, Agricultural Experiment Station, Lexington, Ky. Ross, B. B., Polytechnic Institute, Auburn, Ala. Ross, S. H., Cudahy Packing Co., E. Chicago, Ind. Ross, W. H., Bureau of Soils, Washington, D. C. Round, L. A., State House, Providence, R. I. Rudnick, Paul, Armour & Company, Chicago, Ill. Runkel, Homer, Bureau of Chemistry, Washington, D. C. Runyan, E. G., Hutchins Building, Washington, D. C. Ruprecht, R. W., F. W. Lunnell & Co., Philadelphia, Pa. Sale, J. W., Bureau of Chemistry, Washington, D. C. Schreiner, Oswald, Bureau of Plant Industry, Washington, D. C. Seeker, A. F., U. S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, New York, N. Y. (Since deceased.) Seidell, Atherton, Hygienic Laboratory, Washington, D. C. Sellers, W. S., American Can Company, New York, N. Y. Shorey, E. C., 2705 North Harrison Street, Wilmington, Del. Shrader, J. H., Bureau of Plant Industry, Washington, D. C. Shulenberger, F. W., Eimer & Amend, New York, N. Y. Sievers, A. F., Bureau of Plant Industry, Washington, D. C. Silberberg, Miss B. H., Bureau of Chemistry, Washington, D. C. Sindall, H. E., Austin, Nichols & Co., Inc., New York, N. Y. Sive, B. E., Bureau of Standards, Washington, D. C. Smalley, F. M., Southern Cotton Oil Co., Savannah, Ga. Smith, C. R., Bureau of Chemistry, Washington, D. C. 10 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Smith, E. E., Bureau of Chemistry, Washington, D. C. Smith, H.R., U. S. Food and Drug Inspection Station, Park Avenue Building, Balti- more, Md. Smith, J. G., Bureau of Soils, Washington, D. C. Smither, F. W., Bureau of Standards, Washington, D. C. Spears, H. D., Agricultural Experiment Station, Lexington, Ky. Spencer, G. C., Bureau of Chemistry, Washington, D. C. Stillwell, A. G., Stillwell Laboratories, New York, N. Y. Street, J. P., 405 Indiana Street, Indianapolis, Ind. Sullivan, A. L., State Food and Drug Commission, 16 W. Saratoga Street, Baltimore, Md. Sutton, C. G., B. B. Culture Laboratory, 176 Palisade Avenue, Yonkers, N. Y. Taber, W. C., U. S. Food and Drug Inspection Station, Park Avenue Building, Balti- more, Md. Taylor, G. B., Bureau of Animal Industry, Washington, D. C. Taylor, J. N., Bureau of Animal Industry, Washington, D. C. Thatcher, A. S., Loose-Wiles Biscuit Co., Long Island City, New York, N. Y. Thomas, E. O., Norfolk, Va. Thompson, E. C., Director of Laboratories, New York, N. Y. Thornton, E. W., State Department of Agriculture, Raleigh, N. C. Todd, A. R., State Food and Drug Department, Lansing, Mich. Toll, J. D., The American Fertilizer, Philadelphia, Pa. Tolman, L. M., Wilson & Company, Chicago, Il. Treuthardt, E. L. P., Munitions Building, Washington, D. C. Trowbridge, P. F., Agricultural Experiment Station, Agricultural Ccllege, N. Dak. Valaer, Peter, jr., Bureau of Internal Revenue, Washington, D. C. Van Slyke, L. L., Agricultural Experiment Station, Geneva, N. Y. Veitch, F. P., Bureau of Chemistry, Washington, D. C. Viehoever, Arno, Bureau of Chemistry, Washington, D. C. Vollertsen, J. J., Morris & Company, Chicago, Ill. Walton, G. P., Bureau of Chemistry, Washington, D. C. Weber, F. C., Bureau of Chemistry, Washington, D. C. Weems, J. B., State Department of Agriculture, Richmond, Va. Wessling, Miss H. L., States Relations Service, Washington, D. C. Wherry, E. T., Bureau of Chemistry, Washington, D. C. White, W.S., City Food and Drug Inspection, Cleveland, Ohio. Wihlfahrt, J. E., Fleischmann Co., New York, N. Y. Wiley, H. W., Woodward Building, Washington, D. C. Wiley, S. W., Wiley & Co., Inc., Baltimore, Md. Wilson, J. B., Bureau of Chemistry, Washington, D. C. Withers, W. A., College of Agriculture and Mechanic Arts, Raleigh, N. C. Wright, C. D., Bureau of Chemistry, Washington, D. C. Yanoysky, Elias, Norwalk Tire and Rubber Co., Norwalk, Conn. PRESIDENT’S ADDRESS'?. INSECTICIDE AND FUNGICIDE LEGISLATION IN THE UNITED STATES, WITH ESPECIAL REFERENCE TO THE FEDERAL INSECTICIDE ACT OF 1910. By J. K. Haywoop (Bureau of Chemistry, Washington, D. C.), President. MEMBERS OF THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS: I have read carefully the addresses of past presidents of this asso- ciation and find they have so fully covered the work of the association that I feel I can not add anything that will be of interest to you. I have. therefore, taken the liberty of departing, to some extent, from the time-honored custom of addressing you relative to the direct work of this association—either past, present or future—and have chosen for my subject “Insecticide and Fungicide Legislation in the United States, with Especial Reference to the Federal Insecticide Act of 1910”. While this subject is one which does not specifically deal with the work of the association, I believe that it will interest many, if not all of you. since it is closely allied to our work and is of direct interest to all who are engaged in the enforcement of insecticide and fungicide laws. I will not attempt to follow in detail the numerous insecticide and fungicide laws in the various States which have been enacted and re- pealed, but will attempt to explain the State laws as they existed seven years before the passage of the Insecticide Act of 1910; in a general way, the history of the Insecticide Act of 1910, the provisions of the act, and the method of its enforcement; and the State laws as they exist at the present time, seven years after the enactment of the Insecticide Act of 1910. EARLY STATE INSECTICIDE AND FUNGICIDE LAWS. In 1903, seven years before the passage of the Insecticide Act of 1910, only six States had passed insecticide laws*, namely, California, Louisi- ana, New York, Cregon, Texas and Washington. In so far as I can learn, the first insecticide law passed in the United States was Act No. 131 of the General Assembly of the State of Louisiana‘, 1 Presented Tuesday morning, November 20, 1917, as special order of business for 11.30 o’clock. 2 Since this address was prepared, the writer has discovered that certain States had passed insecticide and fungicide laws which should properly have been included in the address. Reference is therefore made to the following State laws: Colorado, Connecticut, Kentucky, Ohio, and Wisconsin [U. S. Dept. Agr., S. R. A., Insecticide, 21: (1918)]. Subsequent to November, 1917, a considerable number of new State insecticide and fungicide laws have been passed which will shortly be reported in the Service and Regu- ety, Memiomnpsesents of the Insecticide and Fungicide Board of the United States Department of griculture 3 U.S. Bur. Chem. Bull. 76: (1903), 57. 4 Acts of Louisiana, 1890, No. 131, 171; U.S. Bur. Chem. Bull. 76: (1903), 58. 11 12 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 relative only to Paris green, approved by the governor July 10, 1890, and becoming effective September 1, 1890. This law, among other pro- visions, required the board of agriculture or the commissioner of agri- culture to distribute circulars each season, setting forth the brands of Paris green and their percentage of arsenic as claimed by the dealer, and directed that brands containing 50 per cent or more of arsenic be classed as “strictly pure” and brands containing less than 50 per cent of arsenic be classed as “‘impure’’. It further directed that the commissioner of agriculture prepare labels for Paris green marked ‘“‘Guaranteed Strictly Pure” or “Guaranteed Impure”, and containing certain other information. These labels were to be furnished to the manufacturer on payment of a certain sum, if said manufacturers had complied with the various pro- visions of the act. It was made the duty of every person offering Paris green for sale as an insecticide to attach one of these labels to each of their packages of Paris green, a violation of this provision being pun- ishable by a fine. It will thus be noted that the law, to all intents and purposes, established a standard for Paris green, which standard re- quired that pure green contain 50 per cent of arsenic. It is probable that the law really meant 50 per cent of white arsenic (As»O;) and should have so stated, since even the purest Paris green does not contain so much as 50 per cent of metallic arsenic. The next State insecticide law passed in the United States was an act to amend the agricultural law of the State of New York! to prevent fraud in the sale of Paris green. This act became a law March 23, 1898 by the approval of the governor. It required that State manufacturers and dealers in original packages of Paris green file a certificate with the commissioner of agriculture, setting forth the brand of Paris green sold, the number of pounds contained in each package offered for sale, the name of the manufacturer and the place of manufacture, and the amount of arsenic that the Paris green contained. This statement was consid- ered a guarantee to the purchaser that every package of Paris green contained not less than the amount of arsenic set forth in the statement. It further directed that the commissioner of agriculture furnish dealers and State manufacturers of Paris green, who had complied with the above-mentioned provision of the act, with a certificate which would authorize them to deal in Paris green in New York State. The law re- quired that all Paris green, or any product analogous to it, sold or offered for sale in the State as such, contain at least 50 per cent of arsenious oxid, thus establishing a legal standard for this article. Fines for viola- tions of the act were included and a method of enforcing the law out- lined. ‘ Laws of New York, 1898, 1: ch. 113, 215; U.S. Bur. Chem. Bull. 76: (1903), 59. 1920) HAYWOOD: PRESIDENT ’S ADDRESS 13 In Bulletin 204 of the Geneva (New York) Agricultural Experiment Station, published December 1910, it is stated: AMENDMENT TO THE PARIS GREEN LAW. In accordance with the suggestions made by us last year, that portion of the Paris green law which related to the definition of Paris green was changed. The essential portion of the amended law embodying this change is as follows: Paragraph 112. Composition of Paris green or analogous products. Paris green, or any product analogous to it, when sold, offered or exposed for sale, as such, in this state, shall comply with the following requirements: First. It shall contain arsenic in combination with copper, equivalent to not less than fifty per centum of arsenious oxid. Second. It shall not contain arsenic in water-soluble forms equivalent to more than three and one-half per centum of arsenious oxid. Upon looking up this supposed amendment in the New York State statutes, I failed to find it, and have been informed by the Chief of the Bureau of Plant Industry of the New York Department of Agriculture that, while the amendment was prepared, it did not become a law. In 1899 two States, Oregon and Texas, passed insecticide laws or combined insecticide and fungicide laws. The Oregon! law was approved by the governor February 17, 1899, and became effective at once. This law made it unlawful for any person or corporation doing business in the State to sell Paris green, arsenic, London purple. sulphur or any spray material or compound for spraying purposes, in quantities ex- ceeding one pound, without providing with each package sold a certifi- cate signed by the seller, guaranteeing the quality and per cent of purity of the materials. It required that all of the materials mentioned conform to the certificate furnished, and provided a fine for a violation of the act. A method of carrying out the provisions of the act was also outlined. The Texas? law was approved March 25, 1899, and became effective at once. This law was entitled ““AN ACT for the better protection of the farmer in the purchase of commercial fertilizers and commercial poisons used for destroying bollworms and other pests’. Relative to insecticides, it required that before any commercial poison, or any chemical or mixture used as a commercial poison, such as London purple, arsenic, Paris green or any poison used for the purpose of destroying the bollworm or other pests, be sold or offered for sale in the State, a fair sample be taken by the manufacturer, agent, importer or party selling the product. be sent to the professor of chemistry of the Agricultural and Mechanical College under seal, who was in turn to have the sample analyzed after he had been paid an analysis fee of fifteen dollars by the consignor. It was directed that the analysis be printed in the form of a label, which 1 General Laws of Oregon, 1899, H. B. 238, 98; U.S. Bur. Chem. Bull. 76: (1903), 61. ? General Laws of Texas, 1899, ch. 46, 64; U.S. Bur. Chem. Bull. 76: (1903), 61. 14 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 was to bear the name of the manufacturer, the brand of the commercial poison, the essential ingredients contained in the commercial poison and the money value of said poison, and was to be furnished to the manufacturer or dealer at a certain cost. It was made mandatory for each package or quantity of commercial poison to bear the above-men- tioned label, and a fine was provided for a violation of any of the pro- visions of the act. The law also authorized the professor of chemistry to take samples of commercial poisons for analysis to compare them with samples furnished by the manufacturer, and authorized agricul- turists or farmers or purchasers of commercial poisons in the State to take samples under official rules and regulations and forward them for free analysis to the professor of chemistry above-mentioned. In 1901 two more States, Washington and California, passed insecti- cide laws or combined insecticide and fungicide laws. The Washington! law was approved by the governor February 26, 1901, and apparently became effective at once. This law declared it unlawful for any person, firm or corporation doing business in the State of Washington to sell or offer for sale adulterated or low-grade Paris green, arsenic, London purple, sulphur or any spray material or compound for spraying pur- poses. The law set the following standard for Paris green, that it con- tain not less than 50 per cent of arsenic trioxid in combination and not more than 4 per cent of water-soluble arsenic trioxid; and also the following standard for commercial arsenic, that it contain not less than 96 per cent of arsenic trioxid. A fine for a violation of the act was pro- vided, as well as a method for its enforcement. The California? act became a law by constitutional limitation Feb- ruary 28, 1901, and only applied to Paris green to be used as an insecti- cide. It provided that all manufacturers in the State and all dealers in original packages of Paris green, which was used as an insecticide and was manufactured outside the State, submit a sample of the Paris green to the State Agricultural Experiment Station before it was offered or exposed for sale. The sample was to be accompanied by a statement giving the brand of Paris green, the number of pounds in each package to be placed on the market, the name of the manufacturer, place of manufacture, and the amount of combined arsenic contained in the Paris green. This statement was to be considered as constituting a guarantee to the purchaser that the Paris green contained not less com- bined arsenic than the amount stated. It further specified that the Director of the State Agricultural Experiment Station give all parties who had complied with the above-mentioned provision of the act a ! Session Laws of Washington, 1901, ch, 22, 19; U. 8. Bur, Chem. Ball. 76: (1903), 63. “sane and Amendments to the Codes of California, 1901, ch. 53, 69; U.S. Bur. Chem. Bull. 76: 903), 57 1920] HAYWOOD: PRESIDENT’S ADDRESS 15 certificate authorizing them to deal in Paris green in California. It further provided that no person should be entitled to deal in Paris green unless he held such a certificate. The law prescribed the following standard for Paris green: That it contain at least 50 per cent of arsenious oxid and not contain more than 4 per cent of the same in the uncom- bined state. Other provisions of the law provided penalties and a method for its enforcement. THE FEDERAL INSECTICIDE AND FUNGICIDE ACT, KNOWN AS “THE INSECTICIDE ACT OF 1910”. HISTORY. It may reasonably be claimed that the Insecticide Act of 1910 was the incentive for the more comprehensive and more intelligent State legislation relative to insecticides and fungicides such as exists in the United States at the present time. The credit of suggesting Federal legislation relative to this subject is to be given to the Association of Economic Entomologists of the United States, and more especially to Professor E. D. Sanderson of that association. On January 7, 1968 Pro- fessor Sanderson, Director of the New Hampshire Agricultural Experi- ment Station, wrote to Dr. H. W. Wiley, then Chief of the Bureau of Chemistry, Department of Agriculture, stating that at the December 1907 meeting of the Association of Economic Entomologists, the com- mittee on proprietary insecticides, of which he was chairman, had been instructed to ascertain if there were any possibility of securing an inter- pretation of the Federal Food and Drugs Act which would bring pro- prietary insecticides and fungicides within its scope and, if not, to de- termine whether it was feasible to secure an amendment to the law so that it would cover proprietary insecticides and fungicides. On January 14, 1908 Professor Sanderson was informed by Dr. Wiley that the Federal Food and Drugs Act did not cover insecticides and that in his opinion the matter could best be handled by a special insecticide law. Cn February 3, 1908 Professor Sanderson requested that Dr. Wiley formulate a Federal insecticide law. This request was favorably con- sidered by Dr. Wiley, and the preparation of the proposed law was entrusted to the writer, the proposed law being submitted to Professor Sanderson March 4, 1908. Since this was the first draft of the present Federal Insecticide Act, which has been followed to a large extent in subsequent State legislation, it is believed that it will be of some historic interest, and it is therefore printed at the end of this address. It will be noted that the law, as originally drawn up, differed principally from the present law in the following particulars: (1) It applied only to insecti- cides; (2) it provided in certain cases for larger fines than are provided for in the present law; (3) it directed that the act be enforced by the 16 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Bureau of Chemistry; (4) it defined original unbroken package; (5) it stated that the amount of arsenious oxid in Paris green must be 55 per cent: (6) it stated that arsenic in water-soluble forms in lead arsenate must not be equivalent to more than 1 per cent of arsenic oxid; (7) it did not allow the addition of water to lead arsenate under certain re- strictions; (8) it did not declare a product adulterated if it contained substances injurious to vegetation. After this law was submitted to Professor Sanderson, he requested that it be rewritten to cover fungicides. This was done, and the amended law sent to him March 14, 1908. Certain further correspondence was conducted between Professor San- derson and the Bureau of Chemistry, relative to the desirability of incorporating a section in the law to prevent the sale of insecticides or fungicides which would injure vegetation. It was finally decided to in- corporate the paragraph which now constitutes the last paragraph in Section 7 of the act. The proposed law as finally corrected, with the exception of the clause relative to injuring vegetation, was introduced in the Senate April 6, 1908 (60th Congress, 1st Session), as Senate Bill 6515. Con- taining the clause relative to injuring vegetation, it was introduced in the House April 20 (calendar day April 25), 1908, by Mr. E. A. Hayes as House Bill 21262, and April 20 (calendar day April 27), 1908, by Mr. F. O. Lowden (60th Congress, Ist Session) as House Bill 21318. On June 6, 1908 Professor Sanderson wrote to various manufacturers, entomologists and agricultural chemists, inviting them to attend a meeting in New York City on June 18, 1908 to discuss the proposed law introduced as Senate Bill 6515 and House Bill 21318, for the purpose of securing an agreement, so that all could unite upon desirable legislation. The writer was present at this conference. At the meeting certain changes in the bills were agreed to and the presentation of these amendments before the proper authorities was entrusted to a committee composed of Professor E. D. Sanderson, Director of the New Hampshire Agricul- tural Experiment Station, Durham, N. H.; Professor H. E. Summers, Iowa State Entomologist, Ames, Iowa; J. P. Street, Chemist, Con- necticut Agricultural Experiment Station, New Haven, Conn.; R. G. Harris, Grasselli Chemical Company, Cleveland, Ohio; and H. F. Baker, President of the Thomsen Chemical Company, Baltimore, Md. This committee met and organized as an executive committee. A change in the standard for lead arsenate, outlined in the original proposed bill and incorporated in the House and Senate bills above mentioned, was suggested by certain interested parties. Accordingly, a meeting of manufacturers with the executive committee was called in New York on December 8, 1908. The executive committee was instructed to request that the standard for lead arsenate, appearing in 1920) HAYWOOD: PRESIDENT’S ADDRESS 17 the original bill, be dropped and that the standard for this article, ap- pearing in the present Insecticide Act of 1910, be substituted. House Bill 21318 was referrred to the Committee on Interstate and Foreign Commerce in the House, but was not considered by the com- mittee during that session of Congress. Senate Bill 6515 was referred to the Committee on Agriculture and Forestry and was reported by Mr. H. E. Burnham with amendments on February 1, 1909 (Report No. 895). The amended bill differed principally from the bill as origi- nally introduced in the Senate in that it dropped the definition of “‘orig- inal unbroken package’, changed the total amount of arsenious oxid re- quired in Paris green from 55 to 50 per cent, replaced the original stand- ard for lead arsenate by the standard as it appears in the present Insecti- cide Act of 1910, permitted the addition of water to lead arsenate under certain restrictions, and contained a clause relative to certain products subject to the act, declaring them to be adulterated if they contained substances injurious to vegetation. The bill was next introduced as House Bill 2218 in the 61st Congress, 1st Session, on March 18, 1909, by Mr. E. A. Hayes, but still contained some of the provisions objected to by all those interested in the passage of the bill. It was again introduced in the 61st Congress, 2nd Session, Feb- ruary 15, 1910, by Mr. F. O. Lowden as House Bill 20989, in practically the same form as the present Insecticide Act of 1910, except that House Bill 20989 provided that the law be enforced by the Bureau of Chemistry, whereas the present law provides that the law be enforced by such existing bureau or bureaus as the Secretary of Agriculture may desig- nate. In the Senate the bill was again introduced as Senate Bill 6131 by Mr. T. E. Burton in the 61st Congress, 2nd Session, on February 4, 1910, and referred to the Committee on Agriculture and Forestry. The bill as introduced was practically the same as the amended Senate Bill 6515, reported by Mr. Burnham on February 1, 1909 (Report No. 895). It was reported to the Senate by Mr. Simon Guggenheim March 23, 1910 with amendments (Report No. 436), bringing the Senate Bill in accord with House Bill 20989. Senate Bill 6131 was passed by the Senate April 4, 1910 (with slight amendments), and referred to the Committee on Interstate and Foreign Commerce in the House on April 5, 1910. It was reported to the House with amendments on April 12, 1910 (Report No. 990). The only amend- ment worthy of note made in the bill by the House Committee was an amendment to Section 4, evidently intended to direct that the enforce- ment of the law be carried on by such existing bureau or bureaus of the Department of Agriculture as the Secretary of Agriculture might direct, instead of by the Bureau of Chemistry. The change made in Section 4 18 ASSOCIATION OF OFFICIAL ARGICULTURAL CHEMISTS [Vol. IV, No. 1 was ambiguous. Therefore this section was changed on the floor of the House to read as it appears in the present Insecticide Act of 1910. The bill finally passed the House on April 18, 1910. It was referred back to the Senate and passed that body as amended by the House on Apri! 19, 1910. It was approved by the President, April 26, 1910, and became effective on and after the first day of January, 1911. DISCUSSION OF THE ACT AND METHOD OF ITS ENFORCEMENT. The Insecticide Act of 1910 is a Federal! enactment designed to prevent the manufacture, sale or transportation in interstate commerce of adulterated or misbranded insecticides, fungicides, lead arsenates, or Paris greens; to prevent the importation of such misbranded and adul- terated articles into the United States, and the exportation of such articles from the United States. Under the provisions of the act the Government is empowered to proceed criminally against parties who ship misbranded or adulterated insecticides, fungicides, lead arsenates or Paris greens in interstate commerce; against parties who manufacture, sell or offer for sale any of such misbranded or adulterated articles in the District of Columbia or any of the Territories; against parties who export such articles; and against parties who import such articles, and having imported, deliver or offer to deliver in original unbroken packages. The Government is further empowered to make seizures of any of such misbranded or adulterated articles which are being transported from one State, Territory or district to another for sale, or which, having been so transported, remain unloaded, unsold, or in original unbroken packages, and furthermore may seize any such misbranded or adulter- ated articles which are manufactured, sold or offered for sale in the District of Columbia or any Territories of the United States. The act further authorizes the Government to exclude from the country any such adulterated or misbranded articles, or any such arti- cles as are forbidden entry into, or forbidden to be sold, or restricted in sale in the country in which they are made or from which they are exported, or any such article which is otherwise dangerous to the health of the people of the United States. Under the criminal section of the act any person who shall be con- victed of a violation of the law may be fined, for the first offense not to exceed two hundred dollars; and for each subsequent offense not to exceed three hundred dollars, or may be sentenced to imprisonment not to exceed one year, or by both such fine and imprisonment, in the discretion of the court. Some of the principal features of this act are as follows: is os Statutes at Large, 1909-11, 36: (I), 331; U.S. Dept. Agr., Office of the Secretary, Circ. 34, rev.: 917), 12. 1920) HAYWOOD: PRESIDENT S ADDRESS 19 (a) Definite standards for lead arsenates and Paris greens are stated, and it is required that all lead arsenates and Paris greens subject to the act shall conform to these rigid specifications. (b) All insecticides and fungicides (other than lead arsenates and Paris greens) which contain inert ingredients shall bear a statement upon the face of the principal label of each and every package giving the name and percentage amount of each and every inert ingredient contained therein and the fact that it is mert, or, in lieu of this, a state- ment of the name and percentage amount of each and every active ingredient which has insecticidal or fungicidal properties, together with the total percentage of inert ingredients. (c) For insecticides (other than lead arsenates and Paris greens) and for fungicides which contain arsenic or compounds of this metal, a statement must be made on the face of the principal label of the total arsenic, expressed as per cent of metallic arsenic, and total arsenic in water-soluble forms, similarly expressed. (d) No statement, design or device appearing on the label of an insecticide, fungicide, Paris green or lead arsenate shall be false or misleading in any particular. It will at once be seen that all false or exaggerated claims relative to the efficacy of the article constitute misbranding, and the Government is empowered to institute criminal or seizure proceedings as outlined above. (e) All insecticides and fungicides (other than lead arsenates and Paris greens) must be up to the standard under which they are sold (f) No substance or substances shall be contained in any insecticide or fungicide (other than lead arsenates and Paris greens) which shall be injurious to the vegetation on which such articles are intended to be used. The above provisions are the most important ones in the act. While there are various other requirements not so important, it is by a strict en- forcement of these provisions specifically mentioned that the consumer is largely protected against those products which bear misleading claims, which are absolute fakes, and which, while killing insects and fungi, may be injurious to the vegetation on which they are intended to be used. The law is enforced by a board of four members: A representative from the Bureau of Chemistry; from the Bureau of Plant Industry; from the Bureau of Entomology: and from the Bureau of Animal Industry. Working under the direction of the representative from the Bureau of Chemistry are chemists, bacteriologists and microscopists, who make examinations of the insecticides, fungicides and disinfectants (other than those used primarily on horses, cattle, sheep, swine, or goats) to deter- 20 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 mine their composition, and whether or not the claims for the disinfect- ants are misleading. The representative from the Bureau of Plant Industry has a corps of plant pathologists, who test the efficacy claims made on the various fungicide labels and determine further whether or not such fungicides are injurious to the vegetation upon which they are to be used. Under the direction of the representative from the Bureau of Ento- mology there is a staff of entomologists, who test all entomological claims appearing upon the labels and in the literature and, in certain cases, determine whether the insecticides submitted to them are injurious to vegetation when used as directed. Working under the direction of the representative from the Bureau of Animal Industry are chemists and bacteriologists, who examine and determine the composition of the various insecticides, fungicides and disinfectants which are to be used primarily on horses, cattle, sheep, swine or goats, and also determine whether the claims made upon the label for such articles are misleading. In addition to the various scientists actually employed to enforce the Insecticide Act of 1910 in the four bureaus involved, various experts in their respective bureaus are freely consulted and aid the board in determining whether or not the claims for the various products which come under the act are misleading. Among the scientists consulted are pharmacologists and medico-chemical experts in the Bureau of Chem- istry, entomologists who are experts along special lines in the Bureau of Entomology, plant pathologists who are experts along special lines in the Bureau of Plant Industry, and veterinarians, animal pathologists and zoologists in the Bureau of Animal Industry. The board has an executive officer, whose duty it is to direct the activities of all inspectors of the board and see that the various insecti- cides and fungicides which appear upon the market are collected for examination; to attend to all fiscal and business affairs of the board; and to take all necessary action for carrying out the recommendations of the board, including arrangements for hearings, collection of evidence and preparation of cases for reference to the Solicitor of the Department. The exact method of collecting and examining samples may be of interest. The inspectors travel throughout the United States on carefully prepared itineraries, and collect samples of insecticides and fungicides for examination and test to determine whether or not they are in violation of the act. These samples are transmitted to the Insecticide and Fungi- cide Board at Washington, under the seal of the inspectors, with complete records identifying the sample with a specific interstate shipment. These samples are assigned by the board to one or more of the four groups mentioned above that are engaged in the enforcement of the act. If 1920| HAYWOOD: PRESIDENT S ADDRESS 21 these samples are not used primarily on horses, cattle, sheep, swine or goats, they are submitted to the scientists working in the Bureau of Chemistry, for chemical, bacteriological and microscopical examination; if the samples bear insecticidal claims they are also submitted to the entomologists of the board for tests; if they bear plant pathological claims they are further submitted to the plant pathologists of the board for test; and, if they are samples which are for use primarily on horses, cattle, sheep, swine or goats, they are submitted to the chemists, bac- teriologists and consulting scientists of the Bureau of Animal Industry. If, upon examination, any samples are found to violate the provisions of the law, appropriate charges are prepared covering such violations. These charges are submitted to the board, and, if it is considered that there has been a substantial violation of the law, the manufacturer is cited to a hearing and given an opportunity to show any fault or error in the findings of the Department of Agriculture. If, upon examination, no violation of the law is shown, the case is placed in permanent abey- ance. If a non-flagrant violation of the law is shown, the matter is brought to the attention of the manufacturer by correspondence, and he is given an opportunity to correct his labels without resort to the courts. After a manufacturer has answered a citation, a full report of the hear- ing, together with all the papers in the case, is again submitted to the board for decision as to whether the case shall be placed in permanent abeyance, taken up by correspondence, or prosecuted. If prosecution is decided upon, the executive officer of the board assembles the various reports upon the sample, completes the evidence if necessary, and transmits the case to the Solicitor of the Department of Agriculture with the recommendation of the board. On the basis of the facts and charges presented to him, the Solicitor decides from the legal point of view whether or not in his opinion the law has been violated. If he concludes that the law has been violated, the case is then transmitted to the Secre- tary of Agriculture for his action. If he concurs in the findings of the board and the Solicitor, the case is transmitted to the Department of Justice and is forwarded by this Department to the proper United States Attorney for prosecution. Upon the conclusion of cases referred to the courts for prosecution, notices of judgment are prepared and published for the information and benefit of the public. Not only is the law enforced in this manner, but the Insecticide and Fungicide Board issues from time to time Service and Regulatory Announcements and Decisions, interpreting the various provisions of the act for the benefit of shippers and giving them information to aid them in bringing their labels and products into conformity with the provisions of the act. Various basic scientific investigations neces- sary for the enforcement of the law are carried on, and in some 22 ASSGCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 instances the results of the work are published. Thousands of in- vestigations have been made and are being made by the entomologists and plant pathologists of the board to determine whether certain par- ticular ingredients entering into the composition of insecticides and fungicides are active or inert against various classes of insects and fungi. Investigations are also made to determine whether or not specific sub- stances are injurious to the vegetation for which the manufacturer recommends them. The chemists of the board study the methods of manufacturing insecticides and fungicides and the basic reactions that occur in their preparation, develop new insecticides and fungicides, and investigate and evolve new analytical methods for their examination. PRESENT STATE INSECTICIDE AND FUNGICIDE LAWS. (Including laws relative to disinfectants.) At the present time, seven years after the passage of the Insecti- cide Act of 1910, twenty-one States have passed laws, now in force, relative either to insecticides or fungicides (including disinfectants), or both. These States are: California, Colorado, Idaho, Kentucky, Louisiana, Maine, Maryland, Michigan, Minnesota, Montana, New Hampshire, New Jersey, New York, North Dakota, Ohio, Oregon, Pennsylvania, Washington, Wisconsin, Connecticut and Iowa. Some of these laws were passed before the passage of the Federal Insecticide Act of 1910, but most of them were passed after the Federal law became effective, and are in the main more or less patterned after this law. No attempt will be made to discuss these various State laws in detail, since it was not contemplated that this address would attempt to give all the facts relative to the various State laws. However, reference will be mede to all of these laws and the more important features contained therein. In 1904 the State of Louisiana! passed a Paris green law, which was approved by the governor July 6, 1904, became effective August 9, 1904, and is still in force. The law provides for its enforcement by the Louisiana State Board of Agriculture and Immigration, and for the annual distribution by the board of circulars setting forth the brands of Paris green and their percentage of arsenic as claimed by the dealer, and classes them as “‘strictly pure” if they contain 50 per cent or more of arsenic, and “‘impure”’ if they contain less than 50 per cent of arsenic. It is further required that the Commissioner of Agriculture and Immi- gration prepare labels for Paris green marked ‘“‘Guaranteed Strictly Pure” or “Guaranteed Impure’’ and sell these to dealers for a certain sum, and that dealers in Paris green for insecticidal purposes use these 1 Acts of Louisiana, 1904, No. 174, 355; U. S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 114. enw 1920] HAYWOOD: PRESIDENT’S ADDRESS 23 labels to designate their quality of Paris green. It is provided that any person manufacturing, dealing in, selling or soliciting orders in the State of Louisiana for the sale of Paris green shall, when he has agreed to sell any lot of Paris green, notify in writing the Chief State Inspector of Fertilizers of the sale and all the necessary facts relative to the trans- action. The inspector of fertilizers, in turn, is directed to sample the Paris green and forward the sample to the State chemist for analysis. According to the law, no fraudulent Paris green shall be sold in the State, and the price of fraudulent green shall not be collected by any process of law. It is further enacted that Paris green sold in the State or for use in the State, which has not been inspected or stamped, shall be presumed to be fraudulent. The law also makes it the duty of the manufacturer or dealer in original packages of Paris green in the State to give certain facts to the commis- sioner of agriculture relative to his product, among which shall be a guarantee of the amount of arsenic in the green, which shall be considered a guarantee to the purchaser, and the law further requires that, upon the filing of such a statement, the commissioner issue a certificate to the manufacturer or dealer, licensing him to sell Paris green in the State. Penalties are provided for a violation of the act. It will be noted that the law, to all intents and purposes, established a standard for Paris green of 50 per cent of arsenic, which probably means 50 per cent of white arsenic, since even the purest Paris green does not contain so much as 50 per cent of metallic arsenic. In 1905 the State of North Dakota! passed a formaldehyde law, which became effective February 17, 1905, and is still in force. Among other provisions, it requires that formaldehyde when sold, offered or exposed for sale as a fungicide, shall contain at least 40 per cent by weight of formaldehyde and be considered adulterated if it contains less than 38 per cent. Penalties are provided for a violation of the law and a method for its enforcement is outlined. In 1907 Colorado passed a horticultural inspection law, which was approved April 9, 1907, went into effect in 1909, was amended in 19172, and is still in force. Among other provisions, this law states: Sec. 10. It shall be deemed a violation of this Act for any one to sell in Colorado, insecticide poisons such as Paris green. London purple, white arsenic, arsenate of lime, arsenate of lead, acetate of lead, arsenate of zinc, cyanid of potassium, hellebore, pyrethrum powder, or any other materials or preparations sold or offered for sale, for the control of insect pests or plant diseases, that are diluted or mixed with other sub- stances, unless the kind and amount of the adulterations or mixtures are conspicuously printed in the English language upon each and every package sold. Upon all packages i. ae of North Dakota, 1913, 2: ch. 97; 2346. U.S. Dept. Agr., S. R. A., Insecticide, F mish: 2 Laws of Colorado, 1917, ch. 131, 473; U.S. Dept. Agr., S. R. A., Insecticide, 21: (1918), 435. 24 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 of arsenate of lead or arsenite of zinc sold in paste form, the percentage of water, by weight, must be guaranteed. The State Entomologist may inspect, examine and make analyses of insecticide, fungicide or other materials held or offered for sale within the State for the purpose of determining their purity, their strength and their value for the destruction of insects or plant diseases in any stage of their development. He shall have free access during all reasonable business hours upon or into any premises or structures to make examina- tions of insecticides or fungicide materials, and upon tendering payment therefor at the current value, may take any sample or samples for examination, analyses, or tests, the results of which may be published for the information of the public. Penalties are provided for violations of the act and a method for its enforcement is also outlined. In 1907 a law was passed by the State of Pennsylvania! regulating the sale of Paris green in said State. The law was approved May 29, 1907, and became effective September 1, 1907. Since the law has been repealed and a more comprehensive one passed to take its place, it will not be discussed. In 1908 the State of Kentucky? passed a law known as “An Act for Preventing the Manufacture and Sale of Adulterated or Misbranded Food, Drugs, Medicines and Liquors and Providing Penalties for Viola- tions Thereof’, which was approved March 13, 1908, became effective for drugs on and after January 1, 1909, and is still in force, as amended March 23, 1916. This law is largely patterned after the Federal Food and Drugs Act’, but is, of course, adapted for State use. Under the definition of “‘drug’’, it includes Paris green and all other insecticides and fungicides, so that the various provisions of the act which apply to drugs also apply to Paris green and all other insecticides and fungicides. Besides defining adulteration and misbranding, providing for penalties and a method of enforcing the law, etc., it provides for the publication of the analyses and the results of the inspection of samples taken or submitted for examination, under certain restrictions. On March 23, 1916, an amendment‘ to this law was passed which went into immediate effect, and was designed to provide funds for the enforcement of the law. In 1908 the State of New York® passed a law for the prevention of fraud in sale of Paris green and other substances, which became effective May 18, 1908, and is still in force. The law is applicable to Paris green, arsenate of lead, sulphur, lime sulphids, miscible combina- tions of mineral or vegetable oils, sulphate of copper, Bordeaux mixture, or any insecticide or fungicide, or essential ingredient thereof, used for ' Laws of Pennsylvania, 1907, No. 235, 309; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 145. * Acts of Kentucky, 1908, ch. 4, 10; U.S. Dept Agr., S. R. A., Insecticide, 13: (1916), 110. 2U. S. Statutes at Large, 1905-7, 34 (I): ch. 3915, 768; U.S. Dept. Agr., Office of the Secretary, Cire. 21, rev.: (1913), 18. TE Weer = no Assembly of Kentucky, 1916, ch. 44, 486; U.S. Dept. Agr., S. R. A., Insecticide, ® Laws of New York, 1908, 1: ch. 279, 766; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 134. nm Om 1920] HAYWOOD: PRESIDENTS ADDRESS 25 the control of insects, or fungous diseases or any other purpose, within the State. It requires that State manufacturers and dealers in original packages of the above-mentioned commodities file a certificate with the Commissioner of Agriculture setting forth the brands of the commodities, the number of pounds contained in each package offered for sale, the name of the manufacturer and place of manufacture, the percentages and chemical compositions of all essential substances or ingredients. It further requires that all packages of preparations containing arsenic, free or in combination, bear a statement of the percentage of arsenious oxid or its equivalent, soluble or insoluble in distilled water, and that all packages of all the commodities covered by the act bear a label giving all the facts, which are directed to be filed with the Commissioner of Agriculture. The law directs that the Commissioner of Agriculture furnish pur- chasers of original packages of the commodities covered by the law which are manufactured outside the State and are intended to be sold or offered for sale, and manufacturers of the commodities within the State who have complied with the above-mentioned proyision of the act, with a certificate which will authorize them to deal in the com- modities covered by the law in New York State. The law provides that any person who fails to file the statement shall not be entitled to deal, within the State, in the commodities covered by the law. The law requires that all Paris green, or products analogous to it, sold, offered cr exposed for sale in the State, contain at least 50 per cent of arsenious oxid, and defines insecticides and fungicides in much the same way as they are defined in the Insecticide Act of 1910. The procedure to be followed in taking samples and having them examined is outlined. In 1909 the State of Minnesota! passed an act to prevent deception in the sale of Paris green and other insecticides, which became effective from and after August 1, 1909, and is still in force. The law applies to Paris green and other insecticides, and “‘insecticide”’ is defined by the act as Paris green and any other substance or mixture of substances intended to be used for preventing, destroying, repelling or mitigating any and all insects which may infest vegetation. The law requires that Paris green contain at least 50 per cent of arsenious oxid in combination with copper, not more water-soluble arsenic than the equivalent of 3.5 per cent of arsenious oxid, and no substance that injuriously affects its quality or strength, and requires that lead arsenate contain at least 50 per cent of actual lead arsenate, 12.5 per cent of arsenious oxid®, no more water- soluble arsenic than the equivalent of 1 per cent of arsenic oxid, and no 1 Laws of Minnesota, 1909, ch. 62, 60; ch. 100,91; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 2 Probably intended for 12.5 per cent of arsenic oxid. 26 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 added substance that will injuriously affect the quality or strength of the lead arsenate. It is required that the label of the insecticide state in English the name and residence of the manufacturer or distributor or party for whom the insecticide is manufactured, and state the name and, with substantial accuracy, the percentage of each ingredient contained therein. A penalty for the violation of the act and a method for its enforcement are provided. In 1910 the State of Maryland! passed an act relative to foods, drugs, disinfectants, etc., which was approved April 5, 1910, and became effective from and after July 1, 1910. The law is modeled after the Federal Food and Drugs Act, but is adapted for State use and contains the following provision relative to disinfectants: That for the purposes of this Act an article shall be deemed to be misbranded: * * * * * * * As to disinfectants: If in the case of disinfectants manufactured or sold in this State, the manufacturers, sales agents or dealers fail to show on the labels the carbolic acid coefficient or relative germicidal strength of such disinfectants as compared with pure carbolic acid; provided, however, that deodorants and antiseptics having no germicidal strength must be plainly labeled and sold as such and such preparations as have no such germicidal strength, shall not be labeled ‘disinfectants’. Penalties for violations of the act and a method for its enforcement are provided. During 1911 six States, Montana, Oregon, Idaho, Maine, Wisconsin and California, passed laws relative to the control of insecticides or fungicides, or both. The Montana? law was approved February 15, 1911, became effective at once, and is still in force. It follows closely the provisions of the Insecticide Act of 1910, but is adapted for State use. A law relative to lime-sulphur solutions and compounds was filed in the office of the Cregon® Secretary of State on February 21, 1911, became immediately effective, and is still in force. It requires that no lime and sulphur solution or compound fer spraying purposes shall be sold or offered or exposed for sale unless it has a specific gravity of 30° Baumé or more, and contains only products which arise from boiling lime and sulphur in water without the addition of salt or other soluble substances. It further requires that each package of the above-mentioned products be labeled to show the contents of the compound or solution and the gravity thereof. A penalty is provided for a violation of the act. 1 Laws of Maryland, 1910, ch. 156, 146; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 120. ? Laws of Montana, 1911, ch. 26, 38; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 127. 3 General Laws of Oregon, 1911, ch. 146, 198; UF. S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 144. 1920] HAYWOOD: PRESIDENT’S ADDRESS 27 The Idaho law relative to insecticides is an amendment to the horti- cultural law of Idaho'. The law was amended in 1911? (approved and effective March 8, 1911) to add Sections 1326-C and 1326-D relative to lime-sulphur solution and further amended in 1913* (approved and effective February 24, 1913) to add Sections 1326-G and 1326-H rela- tive to lead arsenate, and make changes in Sections 1326-C and 1326-D relative to lime-sulphur solution. Following are the only provisions of the act which are of interest in connection with this paper: Sec. 1326-C. All spray solution known as a lime and sulphur liquid shall be con- spicuously labeled as to the strength of the solution showing a guaranteed strength of lime and sulphur combined in solution as sulphates and sulphids, of which solution not less than seventy per cent (70 per cent) by weight shall be sulphur, and such label or labels shall also contain a direction as to the proportions of water to be used in any mixture containing a four per cent (4 per cent) solution by weight of lime and sulphur combined as sulphates and sulphids, of which solution not less than seventy per cent (70 per cent) by weight shall be sulphur. Any violation of the provisions of this section shall constitute a misdemeanor and shall be punished as provided in Section 1324. Sec. 1326-G. ¥ - ‘4 = - oe All arsenate of lead sold for the purpose of being manufactured into arsenate of lead solution shall contain not more than fifty per cent water, not less than twelve and one- half per cent arsenic oxid, not more than three-fourths of one per cent water-soluble arsenic oxid. Any violation of the provisions of this section shall constitute a mis- demeanor and shall be punished as provided in Section 1324. It will be noted that the standard for lime-sulphur solution stated in this act is an impossible standard for lime-sulphur solution, since lime and sulphur do not combine merely to form sulphates and sulphids, but combine to form sulphids, thiosulphates, sulphates and possibly sulphites. A solution of lime-sulphur can not possibly contain 70 per cent by weight of sulphur. The Maine? law, known as “An Act to amend and unify the laws regulating the sale of agricultural seeds, commercial feeding stuffs, com- mercial fertilizers, drugs, foods, fungicides and insecticides’, was ap- proved March 28, 1911, and became effective January 1, 1912. Action was taken to amend and unify the Jaw® in 1913, and the law which is now in force became effective January 1, 1914. This law, in so far as it applies to insecticides and fungicides, is modeled closely after the Federal Insecticide Act of 1910, but is adapted for State use. It differs prin- cipally from the Federal act in that it requires a statement on the label of the number of net pounds in the package and in that the manufacturer is not given the choice of stating on his label the names and percentage amounts of each and every active ingredient and the total percentage 1 Idaho Revised Codes, 1908, 1: 605; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 108. ? Idaho Session Laws, 1911, ch. 58, 159; U. S. Dept. ‘Agr., S.R. AS Insecticide, 13: (1916), 108. 3 Ibid., 1913, ch. 18, 87-8; U. S. Dept. Age. S. R. A., Insecticide 13: (1916), 109. ‘« Laws of Maine, 1911, ch. 119, 114; U Dept. Agr., . R. A., Insecticide, 13: (1916), 117. § [bid., 1913, ch. 140, 180; ch. 164, 214; U.S. Dept. es S.R. A., Insecticide, 13: (1916), 117. 28 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 of inert ingredients, in lieu of stating the names and percentage amounts of each and every inert ingredient. The section of the Maine law covering this matter reads as follows: For the purpose of this act an article shall also be deemed to be misbranded. * * * * * * * In case of fungicide and insecticide: * * * + * * * Sixth. If it consists partially or completely of an inert substance or substances which do not prevent, destroy, repel, or mitigate insects or fungi and does not have the percentage amount of such inert ingredient plainly and correctly stated on the label. The Maine law also specifically authorizes the Commissioner of Agri- culture to fix and publish standards of purity, quality or strength, when such standards are not fixed by law. The Oregon! law, which is still in force, known as “AN ACT Pro- hibiting the sale of misbranded insecticides, Paris green, lead arsenate, or fungicide, etc.’’, was filed in the office of the Secretary of State Febru- ary 23, 1911, and by reason of its not containing an emergency clause, went into effect May 20, 1911, ninety days from the end of the session of the Legislature Assembly at which it was enacted. The law contains a provision repealing the former State insecticide act of Oregon, men- tioned at the beginning of this paper. This law is closely modeled after the Federal Insecticide Act of 1910, but is adapted for State use. The section of the law requiring a statement relative to inert ingredients on the label is different from a similar section in the Federal act and reads as follows: That for the purpose of this act an article shall be deemed to be misbranded— * * * * * * * In the case of insecticides (other than Paris greens and lead arsenates) and fungi- cides: * * * third, if it consists partially or completely of an inert substance or substances, which do not present [prevent], destroy, repel, or mitigate insects or fungi, and does not have the names and percentage amounts of each and every one of such inert ingredients plainly and correctly stated on the label. Also, this law contains the following important provision which does not appear in the Federal Insecticide Act: That for the purpose of this act an article shall be deemed to be misbranded— In the case of insecticides, Paris greens, lead arsenates, and fungicides: * * * fourth, if the label does not state the chemical formula of the compound or compounds which shall constitute the insecticide, Paris green, lead arsenate or fungicide, contained within the package. The Wisconsin? law was approved and became effective in June 1911, and is still in force as amended in 1915. It is modeled closely after the Federal Insecticide Act, but is adapted for State use. A slight mistake } General Laws of Oregon, 1911, ch. 205, 328; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 142. ? Wisconsin Statutes, 1911, ch. 61, 991; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 150. 1920} HAYWOOD: PRESIDENT’S ADDRESS 29 was made in quoting one section of this law in Service and Regulatory Announcement, Insecticide, No. 13, U. S. Department of Agriculture, which was due to an error in the Wisconsin State leaflet issued by the entomologist of Wisconsin, giving the text of the law. Under the section ‘“Misbranding defined.—Section 1494—10y. 2. (b)”’, the provision relative to active and inert ingredients should read: In the case of insecticides (other than Paris green and lead arsenates) and fungi- cides: * * * third, if it consists partially or completely of an inert substance or substances which do not prevent, destroy, repel or mitigate insects or fungi, and does not have the names and percentage amounts of each and every one of such inert in- gredients plainly and correctly stated on the label; that in lieu of naming and stating the percentage amount of each and every inert ingredient the producer may at his discretion state plainly upon the label the correct names and percentage amounts of each and every ingredient of the insecticide or fungicide having insecticidal or fungi- cidal properties, and make no mention of the inert ingredients, except in so far as to state the total percentage of inert ingredients present. In 1915 the following amendments were made in this law!: A section known as Section 1494-2 was passed, which reads in part as follows: Section 1494-2. It shall be the duty of the state entomologist to enforce the laws relating to * * * the inspection of insecticides and fungicides. Section 1494—10q was repealed. Section 1494-10w was amended to read as follows: A fee not to exceed five dollars may be collected for the examination or analysis of each sample of insecticide or fungicide submitted by any manufacturer, wholesaler, jobber or dealer. Such fees shall be paid into the * * * State treasury. The California? law, as first passed, became effective July 1, 1911, but was amended? in 1913, so that at the present time it is in force in the form reported in Service and Regulatory Announcement, Insecticide, No. 13%. It specifically repeals the 1901 California Paris green law, previously mentioned in this paper. The law, as at present in force, is largely modeled after the Federal Insecticide Act of 1910; however, it contains certain additional important provisions. It requires that commercial insecticides and fungicides and materials to be used for insecticidal or fungicidal purposes bear a label stating the name, brand and trade-mark, the name and address of the manufacturer, importer or dealer, the place of manufacture, a correct general statement of the nature and composition, and the total percentage of the substance or substances alleged to have insecticidal or fungicidal properties. It further directs that the provisions of Section 7 of the act, relative to 1 Laws of Wisconsin, 1915, ch. 413, 518; U.S. Dept. Agr., S. R. A., Insecticide, 21: (1918), 446. 2Statutes and Amendments to the Codes of California, 1911, ch. 653, 1248. 3 Jbid., 1913, ch. 211, 363; ch. 612, 1141. 4U.S. Dept. Agr.,S. R. A., Insecticide, 13: (1916), 102. 30 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 adulteration, shall not apply to an article if the standard of strength, quality or purity be plainly stated on the container, even though the standard differs from that determined by Section 7 of the act. The law also exempts certain insecticidal and fungicidal substances from the application of the act, outlines a method of taking samples and directs that results of analyses and other important information be published at least yearly. On September 1, 1911, a Texas! fertilizer law became effective, which is stillin force. This law, in Section 19, repeals Chapter 46 of the General Laws of 1899, previously mentioned. The State of Texas, therefore, has no insecticide law at the present time. In 1912 “AN ACT to regulate the sale of insecticides’ was passed by the State of New Jersey?, was approved March 19, 1912, became immedi- ately effective, and is now in force. The law, with provisions adapting it to State use, is largely modeled after the Federal Insecticide Act of 1910, except that it is not nearly so comprehensive. The law applies only to insecticides and not to fungicides, and does not include most of the misbranding provisions contained in Section 8 of the Federal In- secticide Act. It does require, however, that every manufacturer of insecticides in the State, and every dealer in original packages of insecti- cides manufactured outside the State, shall each year submit to the State chemist a statement giving the brand or brands of insecticides to be sold, the name of the manufacturer and place of manufacture and the minimum amount of total arsenic and maximum amount of water- soluble arsenic. If the insecticide does not contain arsenic, the professed standard must be stated. The law further requires that the statement furnished shall be printed and attached to each package sold by the retail dealer and that it shall be considered a guarantee of the composi- tion of the material. It is further directed that if the material is sold in bulk, this guarantee must be attached to the container and a copy of the guarantee given upon a request from the purchaser. The State chemist is directed to issue a certificate to the party filing the above- mentioned statement, which authorizes the party to deal in the brand of insecticide named. A method of enforcing the act and penalties for its violation are provided, and the State chemist is directed to publish the analyses and other pertinent facts at least annually. In 1913 the State of North Dakota® passed an insecticide and fungicide act, which was approved February 21, 1913, became effective July 1, 1913, and is still in force. This law is patterned very closely after the 1 General Laws of Texas, 1911, ch. 109, 218. * Laws of New Jersey, 1912, ch. 89, 122; U.S. Dept. Agr.,S. R. A., Insecticide, 13: (1916), 132. aoe Laws of North Dakota, 1913, 2: ch. 97, 2346; U.S. Dept. Agr., S. R. A., Insecticide, 13: bs »), oO. = ae © eS a - 1920) HAYWOOD: PRESIDENT’S ADDRESS 31 Federal Insecticide Act of 1910. Penalties are provided, as well as a method for the enforcement of the act. In 1913 the State of Ohio! passed “AN ACT to regulate the manufac- ture and sale of insecticides and fungicides in Chio”’, which was approved April 16, 1913, and is still in force in a very slightly modified form. The changes made in the 1913 law consist in using the term “Secretary of Agriculture” wherever the words “The Agricultural Commission of Ohio” are used and in dropping the following words in Section 14, “Any unexpended balance shall be credited to the agricultural fund”. This law is modeled after the Federal Insecticide Act of 1910, but contains certain important additional provisions. !t requires that every package of insecticide, fungicide or essential ingredients thereof, sold or manufactured in the State, bear a statement giving the net pounds of solids, the net pounds of paste arsenate of Jead on a 50 per cent water basis, the number of gallons of liquids, the name, brand, trade-mark, name of manufacturer and place of manufacture, and the percentages and chemical compositions of all essential substances or ingredients. In the case of lime-sulphur solution, it is required that the label state the degree Baumé and the per cent of sulphur. All the aboye informa- tion is to be considered as constituting a guarantee to the purchaser. A standard is given in the acti, both for paste arsenate of lead and powdered arsenate of lead. The law provides penalties for violations of the act and contains provisions outlining the method of enforcement. In 1913 the State of Michigan? passed “AN ACT For preventing the manufacture, sale or transportation of adulterated or misbranded Paris greens, lead arsenates and other insecticides, and also fungicides, and for regulating traffic therein”, which was approved May 7, 1913, and is still in force. This law is modeled very closely after the Federal Insecti- cide Act, but differs from it in one important particular. Instead of the wording of the Federal act relative to the statement of inert ingredients or active and inert ingredients, the Michigan law simply says: For the purpose of this act an article shall be deemed to be misbranded, * * * * * * * In the case of insecticides (other than Paris green and lead arsenates) and fungicides: * * * * * * * Third, If it does not state plainly upon the label the correct names and percentage amounts of each and every ingredient of the insecticide or fungicide having insecticidal or fungicidal properties and the total percentage of inert ingredients present. Penalties are provided and a method of enforcing the law outlined. In 1915 the State of Washington? passed “AN ACT Relating to horticulture and horticultural plants and products, etc.’’, which was 1 Legislative Acts and Joint Resolutions of Ohio, 1913, 103: H. B. No. 230, 161; U. S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 139. 2 Public Acts of Michigan, 1913, No. 254, 476; U.S. Dept. Agr.,S. R. A., Insecticide, 13: (1916), 124. 3 Laws of Washington, 1915, ch. 166, 494; U.S. Dept. Agr., a A., Insecticide, 13: (1916), 146. 32 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 approved by the governor March 19, 1915, became immediately effec- tive, and is still in force. This act, in so far as it applies to insecticides and fungicides, is modeled closely after the Federal Insecticide Act. Penalties are provided and a method of enforcing the act is outlined. In 1915 the State of New Hampshire! passed “AN ACT To regulate the sale and to standardize the strength and purity of fungicides and insecticides’, which was approved April 14, 1915, became effective September 1, 1915, and is still in force. This law is modeled after the Federal Insecticide Act, but differs from it in the following important particulars: Section 1 of the act reads as follows: Every lot or package of fungicide or insecticide which is manufactured, sold, dis- tributed, or offered or exposed for sale in this State shall have affixed in a conspicuous place on the outside thereof a plainly printed statement clearly and truly stating the net ounces or pounds in the package or container, the name or trade-mark under which the article is sold, the name and address of the manufacturer or shipper, the place of manufacture, and also a statement of the chemical or physical composition of the material as follows: First, in case of Paris green and lead arsenate, the minimum per centum of total arsenic and the maximum per centum of water-soluble arsenic which it contains; second, in the case of fungicides and insecticides, other than Paris green and lead arsenate, the name and per centum of active ingredients, or the quality or strength under which the material is sold, and in addition the per centum of inert materials which it contains, as hereinafter provided. The act, in Section 7, has the same requirements relative to a state- ment of total and water-soluble arsenic and inert ingredients or active and inert ingredients, as the Federal Insecticide Act. The act also specifically requires a statement on the label of the weight or measure and contains a standard for powdered lead arsenate. Penal- ties are provided and a method of enforcing the act outlined. In 1917 Connecticut, Iowa and Pennsylvania passed laws relative to insecticides or fungicides (including disinfectants), or both. The Connecticut? law relates only to disinfectants and is as follows: AN ACT concerning the testing and labeling of disinfectants. Be it enacted by the Senate and House of Representatives in General Assembly convened: The receptacle containing any disinfectant for external use, the phenol coefficient of which can be determined by a bactericidal test, manufactured, sold, or offered for sale within the State shall bear a label showing the carbolic acid coefficient or relative germicidal value of such preparation as compared with pure carbolic acid. The rela- tive germicidal value of a disinfectant shall be determined by the application of either the Rideal-Walker or the Hygienic Laboratory method. Any such disinfectant shall be misbranded if the statement contained on the label is false. Any person who shall misbrand any disinfectant within the meaning of this act or shall sell or offer the same for sale shall be fined not more than one hundred dollars, or imprisoned not more than sixty days, or both. 1 Laws of New Hampshire, 1915, ch. 118, 135; U.S. Dept. Agr., S. R. A., Insecticide, 13: (1916), 130. ? Public Acts of Connecticut, 1917, ch. 314, 230; U.S. Dept. Agr.,S. R. A., Insecticide, 21: (1918), 437. 1920] HAYWOOD: PRESIDENT’S ADDRESS 33 The Iowa! law, entitled “AN ACT to prevent the manufacture and sale of adulterated or misbranded insecticides and fungicides within the State’, was approved April 25, 1917, became effective July 4, 1917, and is still in force. The law is modeled after the Federal Insecticide Act, but contains certain different important provisions, as follows: It requires that insecticides and fungicides sold in package form be labeled to show the quantity of contents in terms of weight, measure or numerical count and provides that reasonable variations shall be permitted and tolerances established by the State Dairy and Food Commissioner. The law also has the following requirement relative to lime-sulphur: All spray solution known as a lime and sulphur liquid shall be conspicuously labeled as to the strength of the solution, showing a guaranteed strength of lime and sulphur combined in solution as sulphates and sulphids, of which solution not less than seventy per cent, 70 per cent, by weight shall be sulphur, and such label or labels shall also contain a direction as to the proportions of water to be used in any mixture containing a four per cent, 4 per cent, solution by weight of lime and sulphur combined as sulphates and sulphids, of which solution not less than seventy per cent, 70 per cent, by weight shall be sulphur. Every package of such compound or solution sold, offered or exposed for sale shall be plainly labeled with black faced type, in letters of not less than one-half of an inch in height, stating the contents of the compound or solution and the gravity test thereof. It will be noted that the standard stated for lime-sulphur solution is an impossible standard, since lime and sulphur do not combine to form only sulphates and sulphids, but to form sulphids, thiosulphates, sul- phates and possibly sulphites. Also, lime-sulphur solution can not possibly contain 70 per cent by weight of sulphur. The law provides for penalties and a method for its enforcement. In the pharmacy laws of the State of Iowa? a drug is defined as follows: Section 4999—a38. The term ‘‘drug’’, as used in this act, shall include all medicines and preparations recognized in the United States Pharmacopeceia or National Formulary for internal or external use, and any substance or mixture of substances intended to be used for the cure, mitigation or prevention of disease of either man or other animals, or for the destruction of parasites. Therefore, any substance used for the destruction of parasites is sub- ject to the various drug provisions of the pharmacy laws of the State of Iowa. The Pennsylvania’ law, known as “AN ACT Preventing the manu- facture, sale, or transportation within the Commonwealth of adulterated or misbranded Paris greens, lead arsenates, lime-sulphur compounds, and other insecticides and fungicides, and regulating traffic therein; providing for inspection of such materials, and imposing penalties’, was 1 Laws of Iowa, 1917, ch. 385, 416; U.S. Dept. Agr., S. R. A., Insecticide, 21: (1918), 438. 2 Supplement to the Iowa Code, 1913, ch. 10-B, 1817. 3 Laws of Pennsylvania, 1917, No. 124, 224; U.S. Dept. Agr., S. R. A., Insecticide, 21: (1918), 443. 34 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 approved May 17, 1917, became effective June 1, 1917, and is still in force. This law repeals the Pennsylvania Paris green law of May 29, 1907, previously mentioned. The law is modeled after the Federal Insecticide Act, but contains the following important additional pro- visions: Section 2. That it shall be unlawful for any person to defraud any other person by misrepresenting the value of any treatment applied to trees, shrubs, vines, or other plant material, or to any animal, for preventing, destroying, repelling, or mitigating any insects, fungus, or bacterial disease, or for accelerating its growth or productive power. The act requires that the quantity of contents be plainly and correctly marked on the outside of the package, in terms of weight, measure, or numerical count. The act does not follow the wording of the Federal Insecticide Act in certain respects, but is changed so as to make the meaning plainer. Fines are provided and a method of enforcing the act outlined. As a whole, this act is probably the most comprehensive and effective insecticide and fungicide law that is now in force. FIRST DRAFT OF PRESENT FEDERAL INSECTICIDE ACT OF 1910. AN ACT For preventing the manufacture, sale, or transportation of adulterated or misbranded Paris greens, lead arsenates, and other insecticides and for regulating traffic therein, and for other purposes. Be il enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That it shall be unlawful for any person to manufacture within any Territory or the District of Columbia any Paris green or lead arsenate or other insecticide which is adulterated or misbranded, within the meaning of this Act; and any person who shall violate any of the provisions of this section shall be guilty of a misdemeanor, and for each offense shall, upon conviction thereof, be fined not to exceed five hundred dollars or shall be sentenced to one year’s imprisonment, or both such fine and imprisonment, in the discretion of the court, and for each subsequent offense and conviction thereof shall be fined not less than one thousand dollars or sentenced to one year’s imprisonment, or both such fine and imprisonment, in the discretion of the court. Sec. 2. That the introduction into any State or Territory or the District of Columbia from any other State or Territory or the District of Columbia, or from any foreign country, or shipment to any foreign country of any Paris green or lead arsenate or other insecticide which is adulterated or misbranded, within the meaning of this Act, is hereby prohibited; and any person who shall ship or deliver for shipment from any State or Territory or the District of Columbia to any other State or Territory or the District of Columbia, or to a foreign country, or who shall receive in any State or Territory or the District of Columbia from any other State or Territory or the District of Columbia, or foreign country, and having so received, shall deliver, in original unbroken packages, for pay or otherwise, or offer to deliver to any other person, any such article so adulterated or misbranded within the meaning of this Act, or any person who shall sell or offer for sale in the District of Columbia or the Terri- tories of the United States any such adulterated or misbranded Paris green, or lead arsenate or other insecticide or export or offer to export the same to any foreign country, 1920) HAYWOOD: PRESIDENT’S ADDRESS 35 shall be guilty of a misdemeanor, and for such offense be fined not exceeding two hundred dollars for the first offense, and upon conviction for each subsequent offense not exceed- ing three hundred dollars or be imprisoned not exceeding one year, or both, in the discretion of the court; Provided, That no article shall be deemed misbranded or adul- terated within the provisions of this Act when intended for export to any foreign country and prepared or packed according to the specifications or directions of the foreign purchaser when no substance is used in the preparation or packing thereof in conflict with the laws of the foreign country to which said article is intended to be shipped; but if said article shall be in fact sold or offered for sale for domestic use or consumption, then this proviso shall not exempt said article from the operation of any of the other provisions of this Act. Sec. 3. That the Secretary of the Treasury, the Secretary of Agriculture, and the Secretary of Commerce and Labor shall make uniform rules and regulations for carry- ing out the provisions of this Act, including the collection and examination of specimens of Paris greens, lead arsenates and other insecticides, manufactured or offered for sale in the District of Columbia, or in any Territory of the United States, or which shall be offered for sale in unbroken packages in any State other than that in which they shall have been respectively manufactured or produced, or which shall be received from any foreign country, or intended for shipment to any foreign country, or which may be submitted for examination by the Director of the Experiment Station, or agent of any State, Territory, or the District of Columbia, or at any domestic or foreign port through which such product is offered for interstate commerce, or for export or import between the United States and any foreign port or country. Sec. 4. That the examinations of specimens of Paris greens, lead arsenates and other insecticides shall be made in the Bureau of Chemistry of the Department of Agriculture, or under the direction and supervision of such Bureau, for the purpose of determining from such examination whether such articles are adulterated or misbranded within the meaning of this Act; and if it shall appear from any such examination that any of such specimens are adulterated or misbranded within the meaning of this Act, the Secretary of Agriculture shall cause notice thereof to be given to the party from whom such sample was obtained. Any party so notified shall be given an opportunity to be heard, under such rules and regulations as may be prescribed as aforesaid, and if it appears that any of the provisions of this Act have been violated by such party, then the Secre- tary of Agriculture shall at once certify the facts to the proper United States district attorney, with a copy of the results of the analysis or the examination of such article duly authenticated by the analyst or officer making such examination, under the oath of such officer. After judgment of the court, notice shall be given by publication in such manner as may be prescribed by the rules and regulations aforesaid. Sec. 5. That it shall be the duty of each district attorney to whom the Secretary of Agriculture shall report any violation of this Act, or to whom any Director of Experi- ment Station, or agent of any State, Territory, or the District of Columbia shall present satisfactory evidence of any such violation, to cause appropriate proceedings to be commenced and prosecuted in the proper courts of the United States, without delay, for the enforcement of the penalties as in such case herein provided. Sec. 6. That the term “insecticide” as used in this Act shall include any substance or mixture of substances intended to be used for destroying, repelling or mitigating any and all insects which may infest vegetation, man or other animals, or households, or be present in any environment whatsoever. The term “Paris green” as used in this Act, shall include the product sold in commerce as ‘Paris green”’ and chemically known as “‘aceto-arsenite of copper”. The term “lead arsenate” as used in this Act, 36 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 7 shall include the product or products sold in commerce as lead arsenate and consisting chemically of products derived from arsenic acid (H;AsO,;) by replacing one or more hydrogen atoms by lead. The term “original unbroken package” or “unbroken pack- age’, as used in this Act, shall signify the original package, carton, case, can, box, barrel, bottle, phial or other receptacle put up by the manufacturer, to which the label is attached, or which may be suitable for the attachment of a label, making one complete package of the Paris green, lead arsenate or other insecticide. The original package contemplated includes both the wholesale and the retail package. Sec. 7. That for the purpose of this Act an article shall be deemed to be adulterated— In the case of Paris green: First. If it does not contain at least 55 per cent of arsenious oxid. Second. If it contains arsenic in water-soluble forms equivalent to more than three and one-half per cent of arsenious oxid. Third. If any substance has been mixed and packed with it so as to reduce or lower or injuriously affect its quality or strength. Tn the case of lead arsenate: First. If it contains more than 50 per cent of water. Second. If it contains arsenic in water-soluble forms equivalent to more than one per cent of arsenic oxid. Third. If any substance has been mixed and packed with it so as to reduce or lower or injuriously affect its quality or strength. In the case of insecticides, other than Paris green: First. If its strength or purity falls below the professed standard or quality under which it is sold. ; Second. If any substance has been substituted wholly or in part for the article. Third. If any valuable constituent of the article has been wholly or in part abstracted. Sec. 8. That the term ‘“‘misbranded” as used herein shall apply to all Paris greens, lead arsenates, or other insecticides, or articles which enter into the composition of insecticides, the package or label of which shall bear any statement, design, or device regarding such article, or the ingredients or substances contained therein which shall be false or misleading in any particular and to any Paris green, lead arsenate or other insecticide which is falsely branded as to the State, Territory or country in which it is manufactured or produced. That for the purpose of this Act an article shall be deemed to be misbranded— In the case of Paris green, lead arsenates and insecticides other than Paris greens: First. If it be an imitation or offered for sale under the name of another article. Second. If it be labeled, or branded so as to deceive or mislead the purchaser, or if the contents of the package as originally put up shall have been removed in whole, or in part and other contents shall have been placed in such package. Third. If in package form, and the contents are stated in terms of weight, or measure, they are not plainly and correctly stated on the outside of the package. In the case of insecticides other than Paris greens: First. If it contains arsenic in any of its combinations or in the elemental form and the total amount of arsenic present (expressed as per cent of metallic arsenic) is not stated on the label. Second. If it contains arsenic in any of its combinations or in the elemental form and the amount of arsenic in water-soluble forms (expressed as per cent of metallic arsenic) is not stated on the label. Third. If it consists partially, or completely of*an inert substance, or substances, 1920] HAYWOOD: PRESIDENT S ADDRESS 37 which do not destroy, repel, or mitigate insects, and does not have the names and per- centage amounts of each and every one of such inert ingredients plainly and correctly stated on the label: Provided, however, that in lieu of naming and stating the percent- age amounts of each and eyery inert ingredient the producer may at his discretion plainly state upon the label the correct names and percentage amounts of each and every ingredient of the insecticide having insecticidal properties and make no mention of the inert ingredients, except in so far as to state the total percentage of inert ingredients present. Sec. 9. That no dealer shall be prosecuted under the provisions of this Act when he can establish a guaranty signed by the wholesaler, jobber, manufacturer, or other party residing in the United States, from whom he purchases such articles, to the effect that the same is not adulterated or misbranded within the meaning of this Act, designating it. Said guaranty, to afford protection, shall contain the name and address of the party or parties making the sale of such articles to such dealer, and in such case said party or parties shall be amenable to the prosecutions, fines, and other penalties which would attach, in due course, to the dealer under the provisions of this Act. Sec. 10. That any Paris green, lead arsenate or other insecticide that is adulterated or misbranded within the meaning of this Act, and is being transported from one State, Territory, District, or insular possession to another for sale, or, having been transported, remains unloaded, or in original unbroken packages, or if it be sold or offered for sale in the District of Columbia or the Territories, or insular possessions of the United States, or if it be imported from a foreign country for sale, or if it is intended for export to a foreign country, shall be liable to be proceeded against in any district court of the United States within the district where the same is found, and seized for confiscation by a process of libel for condemnation. And if such article is condemned as being adulter- ated or misbranded within the meaning of this Act, the same shall be disposed of by destruction or sale, as the said court may direct, and the proceeds thereof, if sold, less the legal costs and charges, shall be paid into the Treasury of the United States, but such goods shall not be sold in any jurisdiction contrary to the provisions of this Act or the laws of that jurisdiction: Provided, however, That upon the payment of the costs of such libel proceedings and the execution and delivery of a good and sufficient bond to the effect that such articles shall not be sold or otherwise disposed of contrary to the provisions of this Act, or the laws of any State, Territory, District, or insular possession, the court may by order direct that such articles be delivered to the owner thereof. The proceedings of such libel cases shall conform, as near as may be, to the proceed- ings in admiralty, except that either party may demand trial by jury of any issue of fact joined in any such case, and all such proceedings shall be at the suit of and in the name of the United States. Sec. 11. The Secretary of the Treasury shall deliver to the Secretary of Agriculture upon his request from time to time samples of Paris green, lead arsenates and other insecticides which are being imported into the United States or offered for import, giving notice thereof to the owner or consignee, who may appear before the Secretary of Agriculture, and have the right to introduce testimony, and if it appear from the examination of such samples that any Paris green or lead arsenate or other insecticide offered to be imported into the United States is adulterated or misbranded within the meaning of this Act, or is otherwise dangerous to the health of the people of the United States, or is of a kind forbidden entry into, or forbidden to be sold or restricted in sale in the country in which it is made or from which it is exported, or is otherwise falsely labeled in any respect, the said article shall be refused admission, and the Secretary of the Treasury shall refuse delivery to the consignee and shall cause the destruction of any goods refused delivery which shall not be exported by the consignee within three 38 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 months from the date of notice of such refusal under such regulations as the Secretary of the Treasury may prescribe: Provided, That the Secretary of the Treasury may deliver to the consignee such goods pending examination and decision in the matter on execution of a penal bond for the amount of the full invoice value of such goods, together with the duty thereon, and on refusal to return such goods for any cause to the custody of the Secretary of the Treasury, when demanded, for the purpose of excluding them from the country, or for any other purpose, said consignee shall forfeit the full amount of the bond: And provided further, That all charges for storage, cartage, and labor on goods which are refused admission or delivery shall be paid by the owner or consignee, and in default of such payment shall constitute a lien against any future importation made by such owner or consignee. Sec. 12. That the term “Territory” as used in this Act shall include the insular possessions of the United States. The word “person” as used in this Act shall be construed to import both the plural and the singular, as the case demands, and shall include corporations, companies, societies, and associations. When construing and enforcing the provisions of this Act, the act, commission, or failure of any officer, agent, or other person acting for or employed by any corporation, company, society, or association, within the scope of his employment or office, shall in every case be also deemed to be the act, omission, or failure of such corporation, company, society, or association as well as that of the person. Sec. 13. That this Act shall be in force and effect from and after the , nineteen hundred and s day of FIRST DAY. MONDAY—MORNING SESSION. The thirty-fourth annual convention of the Association of Official Agricultural Chemists was called to order by the President, J. K. Hay- wood of Washington, D. C., on the morning of November 19, 1917 at 10.15 at the New Willard, Washington, D. C. No referee on the subject of foods and feeding stuffs was appointed and no report on this subject was presented. No report on sugar in foods and feeding stuffs was made by the asso- ciate referee. REPORT ON CRUDE FIBER. By C. K. Francis! (Agricultural Experiment Station, Stillwater, Okla.), Associate Referee. A sample of wheat shorts and one of cottonseed meal, together with a piece of muslin for use in filtering, were sent to each collaborator. Deter- minations of crude fiber were made by the one filtration method and by the official method. The results are shown in the following table. Examination of the table shows that the results obtained by the one filtration method were considerably higher than those obtained by the official method. Moreover, results by the one filtration method are not so concordant as those by the official method. With the one filtration method it was particularly difficult for the collaborators to check each other. CONCLUSIONS. In the opinion of the collaborators, no saving in time is effected by using the one filtration method, and the failure of the results to check with those obtained by the official method raises a doubt as to whether the proposed method can be used with satisfaction. 1 Present address, Cosden & Company, Tulsa, Okla. 39 40 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Determination of crude fiber. WHEAT SHORTS COTTONSEED MEAL ANALYST Official Proposed Official Proposed method method method method per cent per cent per cent per cent Percy O’Meara, Agricultural Experiment Sta- 5.42 6.02 11.97 12.37 tion, E. Lansing, Mich. 5.22 5.62 12.28 12.31 2 5.53 oe es 12.59 ANVGEAGE Wicomico ceseeeLe eo Sesh Gis dee 5.32 5.72 12.12 12.42 T. E. Friedemann, Agricultural Experiment 5.18 6.17 12.50 13.97 Station, E. Lansing, Mich. 5.35 5.85 12.30 14.12 5.00 6.15 fe 12.60 5.95 ae Average: trece oe neta ee ne eee 5.17 6.03 12.40 13.56 Wm. Weber, State Department of Agricul- 5.24 7.61 11.92 13.73 ture, Harrisburg, Pa. 5.09 6.32 11.76 13.29 AV GLARE. 52 cae Se te ene CE reel eae 5.16 6.96 11.84 13.51 E. R. Harrouff, Agricultural Experiment Sta- 5.30 6.30 12.62 12.00 tion, College Station, Texas. RG 6.70 12.65 12.95 5.90 6.46 sens 13.82 5.60 6.25 cis 14.60 Sac 15.70 Average. 0a ts ae eas 5.50 6.42 12.63 13.81 W. L. Dubois, Hershey Chocolate Co., 5.49 712 11.92 14.23 Hershey, Pa. 6.01 6.07 13.97 14.73 Averaged omses raat aaa 8b O8 LEE 5.75 6.59 12.94 14.48 W. D. Richardson, Swift & Company, Chi- 6.03 6.43 12.58 13.02 cago, Ill. 5.95 6.35 12.85 13.34 Average:.<.s s <.cnjaraaibie a Se eae ce ine 6.11 6.34 12.61 13.21 E. H. Berry, U.S. Food and Drug Inspection 5.15 6.40 12.45 13.58 Seon, Transportation Building, Chicago, 5.05 6.43 12.65 14.00 ANELABES facto cael ee eee ete 5.10 6.41 12.55 13.79 Cornelia Kennedy, University of Minnesota, 5.80 6.14 12.68 14.61 University Farm, St. Paul, Minn. 5.84 5.75 13.21 14.17 AV ELE RG 05. 6.00.00. Osis Ree 5.82 5.94 12.94 14.39 1920) SILBERBERG: REPORT ON STOCK FEED ADULTERATION 41 Determination of crude fiber —Concluded. WHEAT SHORTS COTTONSEED MEAL _ ANALYST | Official Proposed Official Proposed method method method method per cent per cent per cent per cent R. A. Thuma, University of Minnesota, Uni- 6.18 6.67 13.46 13.74 versity Farm, St. Paul, Minn. 6.15 6.63 | 13.67 14.17 SESE IR SORES Con tote k Soe nema 6.16 6.65 13.56 13.95 L. D. Elliott, U.S. Food and Drug Inspection 5.69 | 6.32 12.20 15.75 Station, U.S. Appraiser’s Stores, San Fran- 5.50 | 6.27 | 12.05 15.51 cisco, Calif. ARV CLARE oie steTs 6% S4: Sic gach ates Stee 5.60 6.30 12.13 15.63 J. H. Roop, Purdue Agricultural Experiment 5.50 5.87 11.70 12.47 Station, La Fayette, Ind. 5.48 5.57 11.62 13.67 5.50 6.00 12.45 13.30 IR VEXAD CURR, ofoe i aiersitia. 2 he,2 ern se oles 5.49 5.81 11.92 13.14 REPORT ON STOCK FEED ADULTERATION. By B. H. Sirpersere (Bureau of Chemistry, Washington, D. C.), Associate Referee. The work during the past year on feed adulteration consisted of two parts: the first part on scratch feed based somewhat upon the recom- mendations in the 1916 report on feed adulteration; the second dealing with a method for the determination of hulls in cottonseed meal. PART I. The work on scratch feeds will be considered first. —Two samples were prepared in the following manner and sent to each collaborator: The weed seeds and chaff were carefully cleaned out of some good quality commercial scratch feed which contained no grit. Each jar of both samples was then prepared separately. Three per cent of com- mercial grit and 2 per cent of a weed seed mixture were added to each jar of Sample 1. Six per cent of commercial grit and 8 per cent of a weed seed mixture were added to each jar of Sample 2. The weed seed mixture contained the following seeds, which represent large, medium- sized and small seeds: 42 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Agrostemma githago (corn cockle) ; Vaccaria vaccaria; Polygonum convolvulus (wild buckwheat) ; Chaetochloa glauca (pigeon grass) ; Chenopodium album (lamb’s quarters). The collaborators were asked to make quantitative determinations of both grit and weed seeds, making two analyses if possible, using for one about 10 grams, and for the other about 20 grams. Later, through the work of A. J. Patten, one of the collaborators, and the results of experimentation, the fact was developed that the method used for mixing and drawing out the sample was of considerable importance. The samples were so clean and the ingredients for the most part of such size that the personal factor in making the separations was practically eliminated. The factors which would tend to cause a variation in re- sults were thus narrowed down to two—the method of mixing and sampling, and the size of sample used—principally the former. The results obtained on this year’s work would hardly justify drawing defi- nite conclusions in regard to either of these points. However, for the time being, it would appear advisable to follow the recommendations of the former referee that, with a coarse scratch feed, no less than 20 grams be used for a sample, although if a thoroughly satisfactory method of sampling were devised, it might be possible to obtain accurate results on a smaller sample. As to the method of mixing and sampling, the results indicate that some mechanical method of mixing and sampling, in which the personal factor is reduced to a minimum, is practically a necessity for concordant results. Table 1 shows that in one instance an analyst obtained very good results by mixing on sampling cloth, reducing by quartering, ctc., on a sample weighing only 9.8 grams. But by the same method of mixing and on a sample weighing about twice as much, the same analyst obtained results 25 per cent off on grit and 40.5 per cent off on weed seeds. In another case an analyst obtained correct results by this method of mixing on a sample weighing 37.0 grams, but the same analyst, on a sample weighing 19.8 grams, was 6.6 per cent off on grit and 15 per cent off on weed seeds, while on a sample weighing 10.38 grams, about the same amount as that on which the other analyst mentioned obtained very good results, his are 40.3 per cent off on grit and only 1 per cent off on weed seeds. One analyst who used the sampling cloth for mixing and sampling was 74.0 per cent off on weed seeds and grit combined on a sample weighing 15.26 grams, and another analyst using this method of mixing and a sample weighing slightly more (16.63 grams) was 91.2 per cent off. While these figures are taken from results on Sample 1, those on Sample 2 would lead to the same conclusion, that mixing and quarter- ing on a sampling cloth is not a reliable method of drawing out a sample. 1920] SILBERBERG: REPORT ON STOCK FEED ADULTERATION 43 Another method proposed is to separate the sample into three por- tions by passing it through 10 and 20 mesh sieves. This makes it easier to mix each portion more uniformly. Then, after mixing each of the three portions, weigh and take one-tenth of each for a sample. While this method has not been given so thorough a test as it would seem to merit, the results obtained so far indicate that, while it gives very sat- isfactory results in some instances, uniformly reliable results are not obtained. TABLE 1. Collaborative resulis on Sample 1, scratch feed, containing 3 per cent of grit and 2 per cent of weed seeds. REPORTED WEIGHT METHOD OF SAMPLING AND ANALYST OF : Weed SAMPLE Grit 1s Mixed on sampling cloth, reduced by quartering until | grams percent | per cent of desired size: A. J. Patten, Agricultural Experiment Station, Bbansmps Mich) eet coe poate oes see: 9.787 3.00 1.79 R. B. Deemer, State Chemist, Department of Agri- | 10.38 4.3 2.2 eulture)Darhayette, indi: 2,25 44-62 Aeon 10.76 4.6 3.2 Swift & Company, Chicago, Ill. PATIANT VEE peta hoo sletofs, Ficic a. « oiSic.2 6 3 Syncs ales oe Ae 15.26 8.70* BlySta Beer elas Coote tcc isc hee eee 16.63 9.56* ihe die LEAIOGII Bis Ses Se eee rah ieee ee 19.60 2.25 1.19 ee Ey 8D) CEI CT os. roxexe.c/oica ols, < 205162 cists sins oe Sam evasive 19.8 2.8 2.3 20.98 2.2 2.0 37.0 3.0 2.0 Sample separated into three portions with 10 and 20 mesh sieves, each portion weighed, mixed, and one- tenth of each taken for examination: eriepbatten= 4.00. see PSOE Rae ose belt e ate 14.764 2.98 2.02 et Ele OU Berbers. stooge aioe ae 8 eee AMMONIUM CITRATE SOLUTION MADE AMMONIUM CITRATE SOLUTION MADE = NEUTRAL TO COCHINEAL AS INDICATOR NEUTRAL TO LITMUS SOLUTION Ba g (OFFICIAL) AS INDICATOR g =| z g EO | a Cal ero eg [lett 5 a. | pecen eseare = i Sof | go | suf || soe || Seis || Soe i) = ° aos aos Bos aos = aos aos oa de : e8s | o85 | 285 || 283 S| 228 | e848 2 p ie =e 3.8 Ole a2 22 Se a = 3 SEE ste SEE ok | seg SEE =z] 2 z = Sse | 22 | 22 || ess S| 328 | 32s P 2 ° Seah | 2A Sah 26% Sam % Sa Bae = < = < = < < = | per cent) percent) per cent | per cent | per cent | per cent per cent | per cent | per cent | per cent 1 | 5.12 | 42.92] 29.70 | 13.22 | 38.84] 4.08 31.01 | 11.91 | 36.80 | 6.12 2 | 4.15 | 42.92] 31.77 | 11.15 | 39.78 | 3.14 32.89 | 10.03 | 37.72 | 5.20 3 | 4.49 | 42.92] 31.01 | 11.91 | 39.60} 3.32 32.59 | 10.33 | 36.95 | 5.97 (64) 1920| HASKINS: PHOSPHORIC ACID IN PRECIPITATED PHOSPHATE 65 TABLE 2. Analyses of precipitated phosphate material ground to pass a 100 mesh sieve. AMMONIUM CITRATE SOLUTION MADE AMMONIUM CITRATE SOLUTION MADE 8 NEUTRAL TO COCHINEAL AS INDICATOR NEUTRAL TO LITMUS SOLUTION =) (OFFICIAL) AS INDICATOR B a) ~ = & a Z z bck bet beh brio || act bed ark be °° 7] o ° .] ° ) ° 3 i} ° ° ° = z 228 anf an 2 anf 2 2 a 2 am 2 ae i ° ° ROS BOs aoa BOs AOS R50 aod aoa = sf oa ots of oot oa o oS so 4 = mee orate Zoe ae Zoe Qa Oat OG Fy 3 58 | S58 | Sse | SES || SES | BES | BES | Bee : 2 | gee | 382 | e382 | 232 || $82 | 282 | $82 | 38s i) ) S°8& 26% Sah 26, 28m 22 % 2°58, 23% Fi < 5 < 4 < a < a per cent per cent | percent | per cent | per cent per cent | per cent | percent | per cent 1 42.92 32.64 | 10.28 | 39.83 | 3.09 34.35 | 8.57 37.97 | 4.95 2 42.92 33.28 9.64 | 40.27 | 2.65 35.09 | 7.83 38.17 | 4.75 3 43.02 40.47*| 2.55*) 40.26 | 2.76 34.65 | 8.37 38.27 | 4.75 * Two hundred mesh sieve; 1 gram charge. litmus solution as indicator; also, to study the effect of the two solutions on the product ground to pass a 100 mesh sieve. Unusual care was taken in standardizing the solutions of neutral citrate of ammonia. Considerable difference exists in the two solutions standardized by the two indicators, cochineal and litmus. The results obtained by the two solutions did not seem to be constant in all cases, a somewhat higher available phosphoric acid having been obtained by the citrate solution, standardized with litmus, in all cases where a 2-gram charge was employed. On the other hand, the citrate solution, standardized with cochineal, gave invariably higher results with a 1- gram charge, irrespective of the degree of fineness of the phosphate. The available phosphoric acid obtained by both solutions was appre- ciably higher when used on the phosphate ground to pass a 100 mesh sieve. Finer grinding did not increase the availability of the phosphoric acid to any great extent. The most striking results obtained in the study are noticed in the very much higher yield of available phosphoric acid in all cases where a l-gram charge was used. This would indicate that in a product con- taining such a large proportion of available phosphoric acid (nearly 40 per cent) a 2-gram charge produces a highly saturated citrate solution, resulting in a correspondingly low phosphoric acid availability. It is believed that the subject is of sufficient importance to warrant recogni- tion by the association. RECOMMENDATION. It is reeommended— That the referee on phosphoric acid for 1918 be instructed to make a study of the analysis of precipitated phosphate with a view to modifying 66 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 the present official method, or to substituting therefor some suitable method for the estimation of available phosphoric acid in this class of materials. E. O. Thomas (Paul-Gale-Greenwood Building, Norfolk, Va.), pre- sented a paper giving some results obtained for “Insoluble Phosphoric Acid in Crganic Base Goods”', using the official method?. No report was presented by the committee on basic slag, to coop- erate with the committee on vegetation tests on the availability of phosphoric acid in basic slag. REPORT ON NITROGEN. By H. D. Haskuns (Agricultural Experiment Station, Amherst, Mass.), Referee, and I. K. Purtps (Bureau of Chemistry, Washington, D. C.), Associate Referee. Collaborators were asked to study the West Coast refraction method for the analysis of nitrate of soda and the use of sodium sulphate in place of potassium sulphate in the Gunning method. No samples were submitted but each collaborator was requested to use samples from his own collection. Determination of nitrogen in nitrate of soda by the Ulsch-Street, zine iron, modified Kjeldahl and the ferrous sulphate-zine- soda methods in addition to the West Coast refraction method was requested. WEST COAST REFRACTION METHOD. Moisture—Weigh approximately 10 grams of the material (60 mesh) accurately, spread out on a tared watch glass and dry in a hot air oven at 160°C. for exactly 5 hours; cool in a desiccator and weigh. The loss in weight represents moisture. Insoluble residue —Dissolve approximately 50 grams of the material in 200-300 ce. of hot water and filter, preferably on a weighed Gooch crucible. Make the filtrate up to 1000 cc. and preserve it for the subsequent determinations of the other impurities. Dry the crucible and contents at 120—-130°C. to constant weight. The net weight represents the total insoluble matter. Sodium chlorid.—Titrate 100 cc. of the solution, equivalent to 5 grams of material, with N/10 silver nitrate solution. Before beginning the titration add 1-2 mg. of sodium carbonate to sharpen the end point with the potassium chromate indicator, (1 cc. of a saturated potassium chromate solution). The silver nitrate solution must be added slowly so that the red precipitate of silver chromate disappears as fast as it is formed; otherwise, there is danger of its being occluded in the silver chlorid. The end point is taken at the first permanent reddish tint. One cc. of N/10 silver nitrate equals 0.005846 gram of sodium chlorid. The report should read: ‘‘Total chlorids equivalent to per cent of NaCl’. AJ. Ind. Eng. Chem., 1917, 9: 865. Assoc. Official Agr. ‘Chemists, Methods, 1916, 4. 1920) HASKINS: REPORT ON NITROGEN . 67 Sodium sulphate—In the determination of sulphates use exactly 100 cc. of the filtrate from the insoluble residue determination. Expel nitric acid by evaporation with an excess of hydrochloric acid. Precipitate the sulphuric acid with 10 cc. of 10% barium chlorid solution. Barium sulphate multiplied by 0.60859 equals sodium sul- phate. The result should be stated in terms of sodium sulphate. Potassium orid—Determine the percentage of potassium oxid according to the official method, reporting the results as “Potash equivalent to potassium nitrate”’. RESULTS OF COLLABORATIVE WORK ON NITROGEN. TABLE 1. Determination of nitrogen in nitrale of soda. FERROUS SS ZINC IRON Bee SULPHATE- WEST COAST ANALYST STREET KJELDAHL or METHOD METHOD METHOD eee METHOD per cent per cent per cent per cent per cent W. D. Richardson, Swift & 14.30 14.59 14.15 14.50 14.66 Co., Chicago, Il. 14.53 14.57 7° 14.29 14.57 14.66 14.39 ~ +464 ~~ 44.15 14.51 tee 14.39 14.59 14.29 14.44 IAVELARC® Nelo colemie-s s 14.40 14.60 14.22 14.50 14.66 15.41 15.41 15.41 15.41 15.34 15.27 15.27 15.41 15.41 15.48 15.26 15.44 15.41 15.41 15.35 15.41 15.44 15.34 15.55 Mere: IAVERSPE sw ahts tes, «sise.6.8 15.34 15.39 15.39 15.44 15.39 L. S. Walker, Agricultural 15.41 15.74 15.17 15.19 16.60 Experiment Station, 15.45 15.63 15.17 15.27 16.58 Amherst, Mass. 15.29 15.61 14.93 Sans ae ANVEQARE RS sislok «aie cei 15.38 15.66 15.09 15.23 16.59 15.21 15.41 15.19 14.88 15.33 15.21 15.41 15.11 14.90 15.34 15.31 15.29 14.91 eect Baers INVerages . 2.6 ase. ae 15.24 15.37 15.07 14.89 15.34 15.27 15.82 15.07 15.13 15.65 15.31 15.74 14.95 15.11 15.63 15.48 15.68 Oe, sas ae eee 5 sane 15.80 JAY Gh 15.35 15.76 15.01 15.12 15.64 It was estimated that the time required for the determination of the impurities in the case of the West Coast method was at least three times more than for the direct nitrogen determination by any one of the other methods. It does not seem to your referee that the method has sufficient 68 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 merit to warrant further study, especially as the association has two official and one tentative method for the analysis of nitrate salts. SUBSTITUTION OF SODIUM SULPHATE FOR POTASSIUM SULPHATE IN THE GUNNING METHOD. Four collaborators have reported results on these methods and quite a variety of substances of difficult oxidation were included in the work. TABLE 2. Determination of nitrogen by the Gunning method. ANALYST J. W. Kellogg, State De- partment of Agriculture, Harrisburg, Pa. Averages: ni.toc ema sora WD Richardson. -e eae Asverages Sissi. Soe cae J. J. Vollertsen, Morris & Company, Chicago, Ill. Average... Saateeccs occ So Walker:. 2c oacsc gee AVEQORC.... Fakta eae oe * Average of 20 samples. + Average of 2 samples. MATERIAL Cottonseed meal............ Animal tankage............ Low grade fertilizer......... Ghop)feed.. «32°. Ss ee an te Jersey. peat: © = s:<.2 5s secioese Cottonseed meal............ Gastorspomacese sacs eee Rartanipomace (4.06.19 ieni Dried blood). osc .h seeks. Leather scrap 2.0 oca-- oot Basel goods s2):)20.20 osc cis Se High grade tankage......... Cottonseed meal............ Leather tankage............ Garbage tankage........... eatheriscrap Joss snot Degreased garbage tankage. . . Cottonseed meal*........... Castor: pomace}.... 22-20 son S- Pest Rees ita atone ete Millet straw and seed....... Nitrolene (treated leather)... . Wooliwastey: 2: .Soereeee se Barnyard manuref.......... Goatimanure®.. see Sheep manure.............. Tannery waste........c225-e6 NITROGEN USING POTASSIUM SULPHATE NITROGEN USING SODIUM SULPHATE 1920) PHELPS: EFFECT OF GLASS WOOL 69 DISCUSSION OF RESULTS. Fifty-one samples have been tested in this study, including twenty- one different types of material, many of which are among the most difficult of oxidation. The average percentage of nitrogen obtained on the fifty-one samples by using potassium sulphate was 4.18 per cent; by using the sodium sulphate, 4.17 per cent. In view of these results, it does not seem necessary to accumulate further data on the subject. RECOMMENDATIONS. It is recommended— (1) That work on the West Coast refraction method be discontinued. (2) That the referee for 1918 study the Lunge nitrometer method, which is invariably used by the manufacturers of explosives, for the analysis of nitrate of soda. (3) That the use of sodium sulphate in place of potassium sulphate in the Gunning method be made official. REPORT ON THE STUDY OF THE EFFECT OF GLASS WOOL IN THE FERROUS SULPHATE-ZINC-SODA METHOD FOR NITRATES. By I. K. Puetps (Bureau of Chemistry, Washington, D. C.). From the very few reports which have been made by the collaborators on this method, it has been impossible to draw any definite conclusions. Furthermore, the opinions of various collaborators, obtained by corre- spondence, seem to be at variance. As this method is at present a tentative one, it is recommended that a further study be made before it is either rejected or accepted as official. THE USE OF PERMANGANATE IN THE KJELDAHL METHOD MODIFIED FOR NITRATES. By I. K. Puetps (Bureau of Chemistry, Washington, D. C.). Although very few reports have been made on this study, it has been possible to draw certain definite conclusions regarding the addition of potassium permanganate to the products of boiling with sulphuric acid and mercury. Two series of experiments were outlined. In the first series the directions of the official method were given!. Inasmuch as considerable 1 Assoc. Official Agr. Chemists, Methods, 1916, 8. 70 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 latitude is allowed by these directions, a second series was conducted in which the directions for certain procedures were more specific. Ac- cordingly, the following additional directions were given for this series: (a) Allow the acid mixture and nitrate to stand for 2 hours. (b) Allow the mixture to stand for 4 hours or more (note actual time) after the addition of the thiosulphate. (c) Heat with a low flame for 15 minutes. (d) Digest in the presence of mercury for 3 hours. (e) Use 300 cc. of water instead of 200 cc. for diluting the sulphuric acid mixture. At the end of the boiling with mercury and sulphuric acid, the direc- tions specified the following procedure: If permanganate is to be added, remove the flask from the flame and, holding it upright, add 0.5 gram of finely divided permanganate as directed under each of the following experiments: (a) Omit the addition of the permanganate. (b) Immediately upon the removal of the flask from the flame, add the permanganate as rapidly as possible. (c) Beginning immediately upon the removal of the flask from the flame, gradually add the permanganate in such a manner that 1 minute is required to complete the addition. (d) After allowing the contents of the flask to cool for 5 minutes, add the perman- ganate as rapidly as possible. (e) After allowing the contents of the flask to cool for 5 minutes, gradually add the permanganate in such a manner that 1 minute is required to complete the addition. The cooling, the addition of water, sulphid and sodium hydroxid, and the distillation were made in the usual manner, except as specified under the preceding directions. The results of the first series were not considered because of the divergence in the procedure of the collaborators as allowed in the direc- tions. In this connection it should be mentioned that certain procedures of the official method should be further studied and the directions made more specific. It has been the experience of the referee that more accurate and more concordant results are obtained and the period of hydrolysis shortened if potassium sulphate is added with the mercuric oxid and if the use of permanganate is omitted. It seems desirable, therefore, that a critical study of such a method should be made. Furthermore, the experience of the referee indicates that it is desirable to study in more detail the effect of the time of standing of the nitrate with the sulphuric acid- salicylic acid mixture, before and after adding the thiosulphate; the preliminary heating with the low yellow flame; the vigorous heating before adding mercury and potassium sulphate; and the final vigorous heating in the presence of these catalysts. In this connection it might be pointed out to advantage that complete hydrolysis of many com- 1920) PHELPS: PERMANGANATE IN KJELDAHL METHOD 71 pounds is not assured when the sulphuric acid mixture becomes colorless. Moreover, it seems desirable to study the effect of substituting sodium sulphate for potassium sulphate. In the following experiments 0.2 gram of sodium nitrate, containing 0.03296 gram of nitrogen, was allowed to stand for 2 hours with the sulphuric acid-salicylic acid mixture. After the addition of sodium thio- sulphate, the mixture was allowed to stand for 4 hours. The preliminary heating with a low yellow flame required 15 minutes. After 5 minutes’ vigorous boiling the mercuric oxid was added and the mixture boiled for 3 hours. The results of the second series are given in tabulated form. Nitrogen in sodium nitrate. TREATMENT WITH PERMANGANATE ANALYST habs Immediate After 5 minutes GANATE Rapia | Minato 0] napia | Minato t gram gram gram gram gram J. J. Vollertsen, Morris & Com- | 0.03288 | 0.03206 | 0.03206 | 0.03330 | 0.03248 pany, Chicago, Ill. 0.03288 | 0.03206 | 0.03248 | 0.03288 | 0.03288 W. D. Richardson, Swift & Com- | 0.03313 | 0.03299 | 0.03292 | 0.03285 | 0.03292 pany, Chicago, Il. 0.03306 | 0.03250 | 0.03229 | 0.03285 | 0.03292 L. J. Jenkins, Bureau of Chemistry, | 0.03280 | 0.03252 | 0.03273 | 0.03266 | 0.03280 Washington, D. C. 0.03280 | 0.03266 | 0.03252 | 0.03280 | 0.03280 H. W. Daudt, Bureau of Chemistry, | 0.03284 | 0.03266 | 0.03258 | 0.03274 | 0.03280 Washington, D. C. 0.03293 | 0.03275 | 0.03278 | 0.03276 | 0.03280 It is to be noted that, when the permanganate is added immediately after the flame is extinguished, whether rapidly or slowly, the amounts of nitrogen recovered are lower than when the permanganate is omitted. When 5 minutes are allowed to elapse before the addition of the per- manganate, the results approach more closely those obtained when the permanganate is omitted. These results agree so well with the results of William Frear!, and are in such close accord with the experience of a large number of collabo- rators, whose opinions have been expressed in correspondence as well as in conversation, that the following recommendation is made: RECOMMENDATION. It is reeommended— That as the use of potassium permanganate in the Kjeldahl method modified for nitrates may cause the loss of nitrogen it should be omitted. 1 J. Assoc. Official Agr. Chemists, 1919, 3: 220. 72 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 INVESTIGATION OF THE KJELDAHL METHOD FOR DETER- MINING NITROGEN. By I. K. Paetrs (Bureau of Chemistry, Washington, D. C.), Associate Referee on Special Study of the Kjeldahl Method, and H. W. Daupt' (Bureau of Chemistry, Washington, D. C.). The hydrolysis of pyridin compounds and other refractory compounds was discussed in 19162. Approximately 0.3 gram of pyridin zinc chlorid was hydrolyzed for each analysis, digesting for 2} hours with a boiling mixture of 25 cc. of sulphuric acid, 0.7 gram of mercuric oxid and 10 grams of potassium sulphate. When sodium sulphate was substituted for an equal weight of potassium sulphate the results obtained were below the theory, the error equaling as much as 10 per cent of the total nitrogen. In order to investigate the effect of varying proportions of potassium sulphate, or of sodium sulphate and sulphuric acid in the presence of mercury, return condensers, constructed entirely of lead, were placed in the neck of the flask during hydrolysis. These served not only to prevent the vaporization of sulphuric acid, but also to retain the acid ammonium sulphate even when excessive quantities of potassium sulphate were employed. It was found that, with the return condensers constructed of lead, amounts of potassium sulphate and sulphuric acid in the presence of mercury determine the completeness of the hydrolysis. For instance, in the presence of 0.7 gram of mercuric oxid, when 25 cc. of commercial “96 per cent C. P.” acid and 10 grams of potassium sulphate were used, incomplete decomposition was obtained, but, when 15 cc. of sulphuric acid were used with amounts of potassium sulphate varying from 10 to 30 grams, excellent results were obtained. When more potassium sul- phate was employed, the results were somewhat lower. Sodium sulphate seemed to give varying results. Recent investigations have been made indicating the proportions of sulphuric acid and potassium sulphate or sodium sulphate which may be employed in hydrolyzing mixtures in open flasks without causing volatilization of ammonia from the acid ammonium sulphate. In these experiments the flasks rested in a 23 inch perforation in an asbestos sheet xs inch thick and were supported 4 inches above the top of the burner. The source of heat was a Bunsen flame 7 inches in height, having a cold cone 3 inches in height. No losses in ammonia were observed when the mixture, containing 25 cc. of sulphuric acid and 10 grams of potassium or 8.2 grams of sodium sulphate, was heated for 1 Present address, Jackson Laboratory, E. F DE Pont Co., Wilmington, Del. 2 J. Assoc. Official Agr. Chemists, 1920, 3: 1920| PHELPS: KJELDAHL METHOD FOR DETERMINING NITROGEN 73 24 hours. When 15 cc. of acid with the same amounts of sulphate were used, the losses were very small in some cases and in others negligible. With larger amounts of either of the sulphates, losses occurred in each case becoming large with 20 grams or more of potassium sulphate. When 16.3 grams of sodium sulphate were used, the loss was smaller than that which occurred with the molecular equivalent (20 grams) of potassium sulphate. Further investigations with the use of the lead condensers show the effect of water on the hydrolysis of pyridin zine chlorid. By using 92.5 per cent sulphuric acid it was found impossible to hydrolyze 0.4 gram of pyridin zinc chlorid completely in 25 hours, even with the mixtures of sulphuric acid, mercuric oxid and potassium sulphate found efficient in previous work. With 100 per cent sulphuric acid, the hydrolysis was found to be complete in all cases where suitable proportions of mercuric oxid, potassium sulphate and acid were maintained. In the presence of 0.7 gram of mercuric oxid and 10 grams of potassium sulphate, hydrolysis of 0.4 gram of pyridin zine chlorid was complete in 23 hours, when either 15 or 20 cc. of acid were used, but not when 25 cc. were used. In the presence of 0.2 gram of mercuric oxid, hydrolysis was complete only when 15 ce. of acid were used with 15 or 20 grams of potassium sulphate. With sodium sulphate, hydrolysis was complete only in the presence of 0.7 gram of mercuric oxid, 15 cc. of sulphuric acid and amounts of sodium sulphate varying from 8.2 grams to 16.3 grams. When 20 cc. of acid were used with 8.2 grams of sodium sulphate, the equivalent of 10 grams of potassium sulphate, hydrolysis was not complete. In no case was hydrolysis complete in the time stated (23 hours) in the presence of 0.2 gram of mercuric oxid and sodium sulphate. Experiments on the hydrolysis of pyridin zine chlorid in open flasks indicated that the hydrolysis of 0.4 gram was complete in 24 hours with a boiling mixture of 0.7 gram of mercuric oxid, 10 grams of potassium sulphate and 25 ce. of sulphuric acid. With 15 cc. of acid the results were slightly lower than theory, owing to volatilization of nitrogen. This was indicated by the small amounts of sulphuric acid left after hydrolysis, as well as by the experiments cited earlier. When 8.2 grams of sodium sulphate were substituted for 10 grams of potassium sulphate, hydrolysis was incomplete with 25 cc., but complete with either 15 or 20 ce. of acid. Upon investigation of the influence of the time necessary for hydrolysis, it was found that it varied with different proportions of acid and potas- sium or sodium sulphate. For instance, with condensers and with 0.7 gram of mercuric oxid and 15 ce. of sulphuric acid, the hydrolysis of 0.4 gram of pyridin zinc chlorid with 10 grams of potassium sulphate was far from complete in 1 hour, but complete in 13 hours, while with 15 74. ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 grams of potassium sulphate it was practically complete in 1 hour. Hydrolysis with 0.7 gram of mercuric oxid, 12.2 grams of sodium sul- phate and 15 cc. of sulphuric acid was incomplete in 15 hours, but complete in 23 hours. In a number of experiments conducted with open flasks in the presence of 0.7 gram of mercuric oxid and 10 grams of potassium sulphate, hy- drolysis with 25 cc. of sulphuric acid required 2 hours, while with 20 cc. of acid only 14 hours were required. With 8.2 grams of sodium sul- phate, instead of 10 grams of potassium sulphate, and 15 or 20 ce. of sulphuric acid, 2 hours were required, while 13 hours showed complete hydrolysis. It is to be noted that with the use of the open flasks another factor, the rate of volatilization of acid, is introduced. This effect depends mainly on the intensity of heating and to a less extent on the time of boiling. The hydrolysis of certain organic compounds of various constitutions was reported in 1916'. In the presence of 0.7 gram of mercuric oxid, 10 grams of potassium sulphate and 25 cc. of sulphuric acid, weights of the compounds varying from 0.2 to 0.4 gram were hydrolyzed completely by heating in open flasks at the boiling point for 2} hours. The use of sodium sulphate in the place of potassium sulphate has been applied to the compounds given below. Reliable results were obtained when these compounds were boiled for 23 hours with mixtures of 0.7 gram of mer- curic oxid, 8.2 grams of sodium sulphate and 20 ce. of sulphuric acid. Below are grouped the compounds studied. Glucosamin hydrochlorid. Isoquinolin derivatives: Tetramethylammonium derivative: Papaverin. Tetramethylammonium iodid. Narcotin. Pyrol derivative: Morphin. Isatin. Hydrastinin. Pyrolidin derivatives: Purin derivative: Atropin. Caffein. Cocain. Imidazole or glyoxalin derivative: Pyridin derivatives: Lophin. Nicotin zinc chlorid. Quinoxalin derivative: Nicotinic acid. Quinoxalin hydrochlorid. Piperidin derivative: Quinazolon derivatives: 8-Eucaine hydrochlorid. 2-Methy! 4-quinazolon. Quinolin derivatives: 2-Methyl 3-phenyl 4-quinazolon. Hydroxyquinolin. Cinchonidin. Strychnin. Brucin. When 25 cc. of acid were used with 8.2 grams of sodium sulphate and 0.7 gram of mercuric oxid, the hydrolysis in many cases was not complete 1 J. Assoc. Official Agr. Chemists, 1920, 3: 306. 1920| PHELPS: KJELDAHL METHOD FOR DETERMINING NITROGEN 75 as with nicotinic acid, nicotin zinc chlorid and hydroxyquinolin. With this mixture, the completeness of hydrolysis depends very markedly on the amount of acid volatilized. The influence of reagents and apparatus was also investigated. Am- monia free water, redistilled from alkaline permanganate solution through a metal Kjeldahl connecting bulb soldered to a block tin condensing tube, was used in this work. The bulb was connected with the flask by means of a cork stopper entirely covered with tin foil. In all experiments where it was desired to avoid the influence of glass or of rubber stoppers, the above apparatus was used. It was noted that the pure reagents of com- merce for the estimation of nitrogen by the Kjeldahl hydrolysis contribute small amounts of ammonia reacting substances. Rubber stoppers in the Kjeldahl flask during hydrolysis! are believed to contribute am- monia reacting substances. Again, rubber stoppers used in connect- ing the Kjeldahl flask to the condenser contribute ammonia reacting substances. The ammonia reacting substances contributed by a rubber stopper held in the neck of a flask during the acid hydrolysis are suf- ficiently large to be appreciable in ordinary routine Kjeldahl deter- minations, unless very closely defined conditions are followed. The error is, furthermore, variable and the use of stoppers unnecessary. Even the especially purified reagents contain traces of such substances. The glass, also, contributes a small amount of alkaline reacting sub- stances. The magnitude of the error due to the alkaline reacting substances is, however, so small that all of these may be neglected except in work in which high precision is necessary. The conclusion is obyious that, in all routine work involving determinations by the Kjel- dahl method, it is necessary to deduct from the result obtained the amount corresponding to the ammonia reacting substances contributed by reagents and apparatus in use in the particular experiments. The results recorded in this investigation were obtained even when greater precautions were taken than is customary in routine work. It is very obyious that under less carefully controlled conditions in routine work the errors, which are here called inappreciable, will become large enough to affect seriously the accuracy of the results obtained. ~ When hydrolysis is made in open flasks, the proportions of sulphuric acid-and potassium or sodium sulphate which may cause loss of am- monia by volatilization have been indicated. The proportions of sul- phurie acid, mercuric oxid and potassium or sodium sulphate giving complete hydrolysis of a refractory compound (pyridin zine chlorid) have been shown. These proportions contain slightly more acid than those which may cause loss of ammonia by volatilization. This difference in proportions is so slight, however, that hydrolysis in open flasks of 1J. Ind. Eng. Chem., 1916, 8: 639. 76 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 refractory compounds must be conducted with closely controlled con- ditions. This is particularly true in the case of sodium sulphate because amounts of sodium sulphate in excess of those proportionate to the suitable amounts of potassium sulphate are necessary. The differences in the behavior of the two sulphates is probably due to differences in the tendencies of the acid sulphates to retain water. Consequently, the hydrolysis of very refractory compounds with sodium sulphate is not at present recommended, although with very closely controlled condi- tions excellent results can be obtained. The influence of the reagents and the apparatus on the accuracy of the modified Kjeldahl method has been indicated. REPORT ON POTASH. By T. D. Jarretu!, (State College of Agriculture, College Park, Md.), Referee. The following samples and instructions were sent to collaborators: Sample No. 1—Commercial potassium chlorid. Sample No. 2.— A mixture of acid phosphate and sulphate of potash-magnesia (con- taining about 9% of potassium oxid). Sample No. 3.—A mixture of acidulated garbage tankage, acid phosphate and com- mercial muriate of potash (containing about 7% of potassium oxid). SAMPLE No. 1. Determine the potash by the official? and the following method: PERCHLORATE METHOD. Dissolve the potash as in the official method. Acidify with about 5 cc. of hydrochloric acid. While the solution is hot, precipitate the sulphate by adding, drop by drop, in slight excess normal barium chlorid solution acidified with hydrochloric acid. Cool, make to volume and shake. Allow the precipitate to settle and filter. Transfer an aliquot, corresponding to 0.25 gram of sample, to an evaporating dish, add 5 cc. of perchloric acid (sp. gr. 1.12); evaporate on a steam or sand bath until it fumes strongly, take up the residue with 5 cc. of water, add a second 5 cc. of perchloric acid and again evaporate the solution carefully until all free hydrochloric acid is driven off and dense white fumes of perchloric acid appear. If the solution goes to dryness and a hard mass remains, take up with a few drops of perchloric acid. When a water bath is used for the evaporation, finally place the dish on a hot plate and heat carefully until hydrochloric acid is driven off. After cooling, add 20 ce. of 95% alcohol and stir well. Allow to stand for 30 minutes. Decant the alcohol through a Gooch crucible having a fairly thick pad (about } inch thick) of as- bestos and wash twice by decantation with 95% alcohol containing 0.2% perchloric acid, made by adding 1 cc. of perchloric acid (sp. gr. 1.12=20%) to 100 cc. of 95% alcohol. Transfer the precipitate to a Gooch crucible with the 95% alcohol containing perchloric acid and wash until the entire filtrate amounts to 75 cc. Finally wash twice } Present address, Bureau of Chemistry, ees DAG: * Assoc. Officiul Agr. Chemists, Methods, 1916, - 1920) JARRELL: REPORT ON POTASH 77 with alcohol-ether (1 part 95% alcohol to 1 part ethyl ether), using 3-5 cc. each time to wash out all perchloric acid. Dry for 30 minutes at 120-130°C., then weigh. Dis- solve the potassium perchlorate from the Gooch crucible with about 200 cc. of hot water and dry to constant weight in an air oven. Allow to cool and weigh. The loss in weight is potassium perchlorate (KCIO,). SAMPLE NO. 2 AND NO. 3. Determine the potash by the official! and the following methods: MODIFIED OFFICIAL METHOD. This is the same as the official method except that the addition of 2 cc. of concentrated hydrochloric acid to the potash solution is omitted. After washing 2.5 grams on the filter paper with boiling water, add directly to the hot solution ammonium hydroxid and ammonium oxalate and proceed as in the official method. PERCHLORATE METHOD. Weigh 2.5 grams of the sample upon a 12.5 cm. filter paper and wash with successive small portions of boiling water into a 250 cc. graduated flask to a volume of about 200 cc. Allow to cool, make to the volume and shake. Do not add ammonium hydroxid or ammonium oxalate. Transfer 50 cc. of the solution to a porcelain or silica dish (do not use platinum), add an excess of a 3% solution of barium hydroxid and without filtering evaporate to dryness over a sand bath. Gently ignite the residue over a Bunsen burner below redness for about 5 minutes. Extract the residue with 25 cc. of boiling water, breaking up the material as much as possible. Filter into an evaporating dish of about 175 cc. capacity, and wash with boiling water until the filtrate amounts to about 150 ce. Add 5 ce. of perchloric acid, evaporate carefully on the sand bath until it fumes strongly, take up with 5 cc. of water, add a second 5 cc. of perchloric acid, evaporate, cool, and proceed as already outlined. It is requested that the modified official method be tested thoroughly (i. e. omitting the addition of 2 cc. of concentrated hydrochloric acid to the potash solution) on some high potash content samples, using acid phosphate, kainit, commercial potassium chlorid. commercial potassium sulphate, and manure salts. Since these mixtures can not be obtained on the market at present, it is suggested that the collaborator prepare them in his laboratory. TaBe 1. Collaborators’ results* of potash determination expressed as potassium ozid. SAMPLE No. 1 SAMPLE NO. 2 SAMPLE NO. 3 | Modified | Modified ANALYST P official | official Official Perchlo— Official peer ate Perchlo- Official | Method Perchlo- method sis method ae ra method | hydro- |. rate method suigge method chloric | method aci acid omitted omitted | per cent | percent | per cent | per cent | per cent | per cent | per ceni | per cent T. D. Jarrell, | 50.22 | 50.70 9.67 9.73 9.41 7.58 7.63 7.18 College of Ag- riculture, Col- lege Park, Md. * Results reported are averages. 1 Assoc. Official Agr. Chemists, Methods, 1916, 12. 78 ANALYST E. F. Berger, Ag- ricultural periment Sta- tion, E. Lan- sing, Mich. per cent Tasie I.—Continued. Collaborator’s results of potash determination expressed as potassium ozid. SAMPLE No. 1 SAMPLE No. 2 Official method per cent 51.45 | 51.07 Official method Modified official method hydro- chloric acid omitted Perchlo- Official me rete aa method ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 SAMPLE NO. 3 chloric acid omitted per cent 9.68 per cent 9.63 Percy O'Meara, Agricultural Experiment Station, E. Lansing, Mich. W. D. Richard- son, Swift & Company, Chicago, Il. D. L. French, Dearborn Chemical Co., Chicago, Ill. 50.15 | 50.22 9.26 10.00 9.53 per cent | per cent 9.65 9.67 7.55 7.50 per cent 7.56 7.67 7.55 | 7.29 50.90 | 50.47 9.38 R. F. Keeler, Ag- ricultural Ex- periment Sta- tion, Geneva, N 49.90 | 49.83 9.62 9.30 7.62 7.60 6.71* 7.44 G. J. Kuhlman, Department of Agriculture, Harrisburg, Pa. 50.68 | 49.44 J.T. Foy, Clem- son Agricul- tural College, Clemson Col- lege, S. C. Wm. Rodes, Agricultural Experiment Station, Lex- ington, Ky. 50.91 | 49.90 49.64 9.96 10.02 8.82 7.38 7.67 7.14 7.47 7.60 C. G. Remsburg, State College of Agriculture, College Park, Md. General Average. 50.98 | 50.16 * Omitted from general averages. 9.58 9.63 9.79 9.69 9.41 9.33 7.35 7.52 7.35 7.45 7.54 7.30 1920} JARRELL: REPORT ON POTASH 79 In Tables 2 and 3 additional results of collaborators working upon special mixtures and raw materials are reported. TABLE 2. Comparative results of potash determination expressed as polassium ozid. MODIFIED OFFI- CIAL METHOD. ANALYST DESCRIPTION OF MIXTURE {Oped anehies RESULTS) (AVERAGE RESULTS) per cent per cent W. D. Richardson. Kainit, acid phosphate and tank- 7.83 7.98 age. Manure salts, acid phosphate and 8.92 8.90 tankage. Potassium chlorid, acid phos- 10.29 10.25 phate and tankage. Potassium sulphate, acid phos- 12.09 11.98 phate and garbage tankage. E. F. Berger and | Potassium chlorid, acid phos- 4.47 4.41 Percy O'Meara. phate, tobacco stems and 4.22 4.22 sheep manure. Potassium sulphate and acid 8.09 7.96 phosphate. 8.08 7.96 Potassium chlorid and acid phos- 12.32 12.30 phate. 12.26 12.15 T. D. Jarrell. Sulphate of potash-magnesia and 5.29* 5.38* acid phosphate. 7.18* 7.35* 10.54* 10.67* Sulphate of potash-magnesia, kai- 8.15* $.24* nit and acid phosphate. Sulphate of potash-magnesia and 7.47* 7.50* base goods. Potassium chlorid and acid phos- 6.64* 6.66* phate. Potassium sulphate, dried fish 7.03* 7.00* and acid phosphate. CERO E Me ml ll fon crom sare satis + Mae ecme ones 8.29 8.29 * Average of three or more closely agreeing results. 80 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 TABLE 3. A comparison of the official and modified official methods for potash. (W. D. Richardson, Analyst.) POTASSIUM OXID DESCRIPTION OF SAMPLE Official method Perchlorate method per cent per cent Kainit, acid phosphate and tankage............. 8.09 8.25 7.97 8.29 Manure salts, acid phosphate and garbage tankage 8.92 9.14 8.90 9.16 Muriate of potash, acid phosphate and tankage. . 10.29 10.17 10.25 10.23 Sulphate of potash, acid phosphate and garbage 12.13 12.33 tankage. 12.09 12.46 Commercial muriate of potash.................. 53.90 54.03 53.72 53.98 Keelip (dried) '2.2.$:2 jer: (G 6 eerayes 2 anaie-bpstetyarcvtetone aeistole 15.71 15.37 15.77 15.46 Commercial fertilizer... sae fe eee ee 11.85 11.90 11.70 12.06 Gorntcobiash: 45:50 2 cise hoc wie aisle ereraperststeia xcs 13.85 14.00 13.88 14.28 Refusetmolasses' ashy 2). cccieo0 cea seeceeo ee eee 39.72 39.72 39.58 39.72 Nebraskajlake potash: vey): ate eases eee nee. 21.71 21.83 21.68 21.68 DISCUSSION BY REFEREE OF METHODS AND RESULTS. MODIFIED OFFICIAL METHOD. The following is a summary of the cooperative work since 1914, in- vestigating the effect of adding hydrochloric acid to the potash solution. 1920] JARRELL: REPORT ON POTASH 81 TaBLe 4. Cooperative results from 1914 to 1917, expressed as potassium ozid. YEAR DESCRIPTION OF SAMPLE rDROcHTLonic eee per cent per cent 1914 Acid phosphate and kainit............. 6.11 6.10 1915 Acid phosphate, kainit and commercial 5.07 5.07 potassium chlorid. 1915 Acid phosphate, dried blood and com- 8.55 8.58 mercial potassium sulphate. 1916 Average of 48 samples of various mixtures. 3.66 3.65 1917 Acid phosphate and double manure 9.63 9.69 salts. 1917 Acid phosphate, tankage and com- 7.52 7.54 mercial potassium chlorid. The cooperative results during the past four years on samples of many different mixtures have shown that no difference is caused by the addition or non-addition of hydrochloric acid to the potash solution. In view of the data here reported, the referee concludes that the addition of 2 cc. of concentrated hydrochloric acid to the water extract of mixed fertilizers and boiling is an unnecessary operation, that its elimination is a desirable simplification and may be effected without sacrifice to accuracy. PERCHLORATE METHOD. The following is a summary of the results reported by collaborators, using the perchlorate and official methods: TABLE 5. Collaborators results, expressed as potassium ozid. SAMPLE No. 1 SAMPLE NO. 2 SAMPLE NO. 3 General average......... Maximum result........ Minimum result........ Official | Perchlo- | Oficial method method method per cent per cent per cent 50.98 50.16 9.63 51.45 51.07 10.00 49.90 49.44 9.26 1.55 1.63 0.74 | Perchlo- = Perchlo- So ae percent | percent | percent 9.33* wie 7.30* 9.67 7.67 7.67 8.82 7.35 7.03 0.85 0.32 0.64 * Results of one collaborator omitted from average. 82 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 The results which are presented in the table indicate that the per- chlorate method is not as satisfactory as could be desired, yet there appears to be an improvement over the results obtained by collaborators in former years. Several chemists obtained excellent results by this method in comparison with the official method. In the determination of potash by the perchlorate method it is ex- tremely important that the details of manipulation be followed closely, and it is believed that the method of procedure, as given in the direc- tions to collaborators, will give reasonable accuracy. Progress with this method has been relatively slow for the reason that collaboration from chemists experienced with the method has been difficult to obtain. So it seems reasonable to assume that the relatively wide differences in the results reported by several analysts may be attributed in a large measure to their inexperience with the method. RECOMMENDATIONS. It is reeommended— (1) That the official method for the preparation of potash solution! be revised to read as follows: Place 2.5 grams of the sample upon a 12.5 em. filter paper and wash with successive portions of boiling water into a 250 cc. graduated flask until the filtrate amounts to about 200 ce. Add to the hot solution a slight excess of ammonium hydroxid and sufficient ammonium oxalate to precipitate all the lime present, cool, dilute to 250 cc. mix, and pass through a dry filter. (2) That the work on the availability of potash be continued. (3) That the study of the perchlorate method be continued. A MODIFIED METHOD FOR THE DETERMINATION OF WATER-SOLUBLE POTASH IN WOOD ASHES AND TREATER DUST. By H. D. Hasxrns (Agricultural Experiment Station, Amherst, Mass.). It is a well established fact that products such as wood ashes, treater dust, or so-called lime-potash, manure ashes, etc., contain a much higher percentage of potash soluble in hydrochloric acid (strength 1 to 1), as well as weaker acid solutions (N/5 hydrochloric acid), than is dis- solved by boiling water. It is conceivable that at least a portion of this water-insoluble potash may be loosely held in combination. with silica as basic silicates, resulting from the process under which the wood ashes and treater dust are made. The presence of more or less of these basic silicates was recognized ! Assoc. Official Agr. Chemists, Methods, 1916, 12. 1920] HASKINS: WATER-SOLUBLE POTASH IN WOOD ASHES 83 by the earlier manufacturers of potash, who established the custom of allowing the ashes to remain in contact with water for a few days before subjecting them to the final leaching with hot water. Ashes thus treated usually gave a larger yield of potash than when leached without the soaking process. Water-soluble potash was determined in a number of samples by the official method. Water-soluble potash was also determined by allowing the ashes to remain for two days in contact with just enough water to cover the ashes contained in a 4-ounce beaker. Subsequently, the ashes were washed with successive portions of boiling water to a volume of 200 cc. and, from this point, the manipulation was according to the official method. One sample of treater dust and 21 samples of ashes were analyzed by the two methods, the acid-soluble potash being de- termined in each case. The results are given in the following table: Potash in wood ashes and treater dust. DESCRIPTION OF SAMPLE AEG Whe ee Se Dies Se ae (ODED POTASH POTASH (OFFICIAL) een) per cent per cent per cent irvetreater(Gust... 2.0. ssc ces oss 12.00 7.41 7.64 Winpdeannes® 9. doctete li. S's gales 3.39 1.92 2.16 “orld COR 2S ene eS Gee aoa ae 7.08 3.95 4.31 WIEASHES ce co oe iene sees 4.46 2.60 2.68 ‘NALS! DELS) ee a 5.40 2.69 | 2.81 (PET GEL A eee ee ee 4.36 2.18 2.28 PWR E ARTES oS om ara e-e 2 'aicie SPadeScreis 1.40 0.70 0.79 “opr Coli? See eee 3.42 2.23 2.21 “NV Edd) SCG 6S 2258s Sane pee 3.07 1.52 1.51 Winsnasnesc ssn. is er. 3.73 2.36 2.32 SWIC ASTCRS 242.555) sfaverclore bis eae tered 9.88 6.75 7.11 VDL. SHG Seen OS eee 0.47 0.11 0.13 Wiesdaasbes. -Al8- 5 As cai oe oes 0.73 0.17 0.09 3.64 2.48 22h 3.77 2.59 2.65 2.93 2.38 2.38 4.11 3.19 3.31 4.23 3.00 3.14 6.17 5.11 ey 3.11 2.26 2.20 6.14 4.18 4.16 7.56 6.62 6.76 * Freshly made dry ashes. This study indicates that freshly made dry ashes and dry treater dust, or cement potash, will yield appreciably more water-soluble potash if allowed to remain in contact with water for several hours previous to extracting with boiling water. In the case of ash products which contain considerable water (12 to 30 per cent), very little advan- tage results from the preliminary treatment with water. It would seem 84 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. 1V, No. 1 that, because of the present scarcity and high price of potash, it might be desirable for the association to make a further study of the subject with a view to adopting some modification of the present official method applicable to ashes and cement potash products. REPORT ON WATER. By J. W. Sate (Bureau of Chemistry, Washington, D. C.), Referee. Three analytical methods were selected for the cooperative work, a rapid method for the determination of calcium and magnesium; a method for barium; and one for manganese. Numerous tests on the determination of free ammonia in water containing hydrogen sulphid were also conducted. This latter work was done in the Bureau of Chem- istry, principally for the reason that sulphid waters change so rapidly in composition that it is not practicable to forward standard samples to collaborators. Three samples of solutions of known composition, together with copies of the proposed methods, were forwarded to each of the collabora- tors. The methods of analysis, composition of standard samples, and results of the cooperative work are given below. The methods of analysis, submitted herewith, have been slightly modified to make them of general application. INDUSTRIAL WATER. CALCIUM AND MAGNESIUM. REAGENTS. (a) Standard potassium permanganate solution, approximately N/5.—Dissolve 6.322 grams of pure crystals in water and make up to 1 liter. Standardize against pure Ice- land spar by the procedure given below. (b) Standard sodium thiosulphate solution, approximately N/5.—Dissolve 49.6 grams of recrystallized sodium thiosulphate in 1 liter of water. Standardize against magnesium ribbon or some suitable compound of magnesium by the procedure given below. (C€) Ammonium arsenate, crystals. (G) Oralic acid, crystals. (€) Potassium iodid, crystals. (f) Sulphuric acid (1 to 1). DETERMINATION?. Acidify and concentrate the sample as usual. Add about 0.5 gram of ammonium chlorid and precipitate the iron and alumina with ammonium hydroxid. Boil, filter and wash. To the filtrate, in a volume of about 100 cc., add 0.5 gram of oxalic acid, together with sufficient hydrochloric acid to clear the solution. Add 1-2 drops of methyl orange, heat to boiling and make slightly alkaline with dilute ammonia. Add immediately sufficient ammonium arsenate to precipitate the magnesium, then slowly add ammonia, with constant stirring, to the hof solution until the magnesium am- 1 J, Ind. Eng. Chem., 1913, 5: 910. 1920] SALE: REPORT ON WATER 85 monium arsenate comes down, or if the calcium oxalate is present in such quantity that this can not be observed, add about 10 cc. of strong ammonia water. Let cool and add 10-15 ce. more of strong ammonia. Let stand for 30 minutes with frequent shaking, filter and wash thoroughly with dilute ammonia water. Transfer the pre- cipitate to a 300-500 cc. Erlenmeyer flask, using dilute sulphuric acid and water. Add 10 ce. of sulphuric acid, make up to about 75-80 cc. and titrate hot with per- manganate solution. Let cool and add 25 cc. more of the acid. Add slowly 5 grams of potassium iodid and immediately titrate to a straw color with sodium thiosulphate. Stopper the flask and cover with black paper, or set in the dark for about 5 minutes. Eight minutes should elapse between the addition of the iodid and the last part of the titration. Without adding starch, complete the titration drop by drop. Read the end point and place the flask in the dark for 1 minute. If there is a return of color, discharge it. Usually there will be none if the last drops of thiosulphate have been added slowly. Apply a correction for iodin set free by the light, ete, by titrating as described above with 10 ce. and 20 ce. of a solution of ammonium arsenate (of which the exact concentration need not be known—about 20 grams to a liter is convenient). If 10 ce. required zx cc. of thiosulphate and 20 ce. required y cc., then the correction is (2x — y) ce. MANGANESE. REAGENTS. (2) Dilute nitric acid (1 to 4).—Free from brown oxid of nitrogen by aeration. (B) Sulphuric acid (1 to 3). (C) Dilute sulphuric acid —Dilute 25 cc. of concentrated acid to 1 liter with distilled water. Add enough permanganate solution to color faintly the dilute acid. (@) Standard manganous sulphate solution —Dissolve 0.2877 gram of pure potassium permanganate in about 100 cc. of distilled water, acidify the solution with sulphuric acid and heat to boiling. Add slowly a sufficient quantity of a dilute solution of oxalic acid to discharge the color. Cool and dilute to 1 liter. One cubic centimeter of this solution is equivalent to 0.1 mg. of manganese. The standard should be prepared by following the same procedure as is used for the sample. This solution is more per- manent than a solution of potassium permanganate, which may, however, be used. To prepare it, dissolve 0.288 gram of potassium permanganate in distilled water and dilute the solution to 1 liter. (€) Sodium bismuthate—Pure dry salt. DETERMINATION. Remove chlorin by two or more evaporations with sulphuric acid from such a quantity of the sample as contains 1.0 mg. or less of manganese. Volatilize the sulphuric acid and ignite the residue gently at less than 500°C. Dissolve in 40 ce. of nitric acid, add about 0.5 gram of sodium bismuthate, and heat until the permanganate color dis- appears. Add a few drops of a solution of ammonium or sodium bisulphate to clear the solution and again boil to expel oxids of nitrogen. Remove the solution from the source of heat, cool to 20°C., again add 0.5 gram of sodium bismuthate, and stir. When the maximum permanganate color has developed, filter through an alundum or Gooch crucible containing an asbestos mat which has been ignited, treated with a solution of potassium permanganate and washed with distilled water. Wash the precipitate with dilute sulphuric acid until the washings are colorless. Transfer the filtrate to a colorimeter tube and compare the color of it with that of standards prepared from the potassium permanganate solution. To prepare the standards, dilute with sulphuric acid, (€), portions of 0.2, 0.4, 0.6 cc., etc., of the permanganate solution to the same volume as the filtrate. 86 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 BARIUM. REAGENTS. (A) Ammonium dichromate solution —One hundred grams to the liter. (b) Ammonium acetate solution —Three hundred grams, neutralized by ammonia, to the liter. (C) Ammonium acetate solution —Twenty cubic centimeters of (b) diluted, to 1 liter. Reaction of acetate solution should be alkaline rather than acid. DETERMINATION. By weighing as barium chromate. Acidify and concentrate the sample as usual. Add about 0.5 gram of ammonium chlorid and precipitate the iron and aluminium with ammonium hydroxid. Boil, filter and wash. To the filtrate add ammonium acetate [10 cc. of (b)] in excess (volume about 200 cc.). Heat to boiling and add, with stirring, about 5 cc. of the dichromate solution, (A). Allow to settle and cool. Decant the clear liquid through a filter, wash the precipitate by decantation with ammonium acetate, (C), until the filtrate is no longer perceptibly colored, which will require about 100 cc. of wash solution. Place the beaker under the funnel, dissolve the precipitate on the paper with warm dilute nitric acid, using as little as possible, and wash the paper. Add a little more acid to dissolve the precipitate in the beaker, follow with ammonia until the precipitate form- ing again no longer redissolves. Heat to boiling, add, with stirring, ammonium acetate [10 ce. of (b)], and ammonium dichromate solution [2 cc. of (€)], allow to cool slowly and wash the precipitate by decantation with (€). Dry the barium chromate, burn the filter separately, ignite moderately to constant weight. Weigh as BaCrQO,. By titration. Proceed as in the method just described to ““* * * wash the precipitate by decantation with (C)”, then proceed as follows: Dissolve the precipitate in about 10 cc. of a mixture of hydrochloric acid (1 to 1) and hot water. Wash the filter and dilute the solution to about 400 cc.; add about 50 ce. of a freshly prepared 10% solution of potassium iodid. Mix carefully and titrate the liberated iodin after 3-4 minutes with standard thiosulphate (1 cc. of N/10 thiosulphate = 4.579 mg. of barium). TABLE 1. Composition of samples sent lo collaborators. CALCIUM AND MAGNE- CONSTITUENTS OE Gas SO Gkee eae mercies CC)) mg. mg. mg. Caletums 27.).2e costes aoe 80.0 61.2 6.1 Magnesium. «055 aoe eee 56.0 214.2 17.1 Sodium): 23) ae ee ee 86.1 247.2 4.0 Strontionn. .29s2.c beste ee eee spike 50.8 ve Manganese ycc2 8-04 castonutatns oe ane 1.16 Bartwumsc yoo aee Ar 97.0 Rc * Bases present in the form of chlorids. 2 + Manganese present in the form of sulphate; other bases present in the form of chlorids. 1920) SALE: REPORT ON WATER 87 TABLE 2. Results of cooperative work on water. BARIUM IN ANALYST CALCIUM IN MAGNESIUM 25 cc. MANGANESE >, 25 cc. IN 25 cc. (PRECIPITATE in 10 cc. IGNITED) mg. mq. mg. mg. J. C. Diggs, State Board of 84.3 35.5 92.7 1.3 Health, Indianapolis, Ind. 81.5 35.2 95.4 1.4 84.2 36.0 91.6 Bee er 95.0 L. R. Taylor, State Water Sur- sae ae 96.6 net vey Division, Urbana, III. ate io 96.9 es aes 96.8 96.8 Dearborn Chemical Company, 79.4 55.1 97.2 Chicago, Ill. 79.1 55.0 97.4 79.3 54.3 97.3 W. F. Baughman, Bureau of 80.8 56.7 96.1 1.10 Chemistry, Washington, 80.8 57.0 95.8 1.05 DC: 80.8 56.4 pte 1.15 F. B. Furber, Bureau of Chem- 81.7 57.3 96.5 ee istry, Washington, D.C 81.7 57.3 96.8 1.2 81.7 ate an 2 J. W. Sale, Bureau of Chemis- 81.4 56.3 96.4 1.18 try, Washington, D.C. 81.4 58.1 96.9 1.10 82.2 57.3 fUbeexrmnennrn ete oe = oso 5c ale 84.3 58.1 97.4 1.4 i HTT SS eas ee 79.1 35.2 91.6 1.05 PRGEFADG Kress fo. See ee te ee 81.3 52.0 96.0 1.20 LUIS ee eee ere 80.0 56.0 97.0 1.16 In considering the results on calcium and magnesium, it should be borne in mind that this method was selected as a rapid volumetric method for use in examining waters for industrial purposes and as a possible substitute for the so-called soap method. Extreme accuracy in this method may be sacrificed if rapidity and reasonable accuracy are attained. The comments of the collaborators, with one exception, indicate that the method is worthy of consideration and that the results submitted, with the exception of one set of magnesium determinations, are sufficiently close to theory, considering the field in which the method is to be used. The remarkably low results on magnesium in the one instance may have been caused by adding an insufficient amount of ammonium arsenate reagent to precipitate all of the magnesium, by a too prolonged washing of the mixed precipitate, or by using an incorrect value for the standard thiosulphate solution. If the low results are due 88 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 to either of the first two reasons suggested, the method could be changed by stating the minimum amount of arsenate reagent to be added, say 2-3 grams, as suggested by one of the collaborators, and by cautioning against prolonged washing of the mixed precipitate. In the referee’s opinion, the indefiniteness of the end point in titrating the iodin with standard thiosulphate is the fundamental criticism to be made of the method. If this objection can not be overcome, the method should not be adopted. However, it is believed that very fair results can be ob- tained if the directions given regarding the titration are closely followed. With regard to the use of Iceland spar, the following directions were forwarded to the collaborators on July 17, 1917: It appears that Iceland spar is not always available for the standardization of the potassium permanganate solution in the determination of calcium. Furthermore, it has been found to contain impurities which may vitiate the results. It is suggested, therefore, that the phrase ‘‘or some suitable compound of calcium” be inserted in the third line under “Reagents (a)” after “* * * pure Iceland spar’’. The referee does not feel warranted, in view of the data at hand, in recommending the adoption of this method until further cooperative work has been done upon it. It is suggested, however, that it be revised as indicated above and that the referee for 1918 be instructed to give it further consideration. The methods for barium and for manganese tested this year, unlike the volumetric method for calcium and magnesium, are old, well-tested methods, in general use. The results on barium obtained by igniting the precipitate are generally slightly low, due probably to reduction of the precipitate on ignition and to the solubility of the barium chromate precipitate in the wash water. The following results, obtained by titrating the precipitate, were sent in by the collaborators: COLLABORATOR BARIUM IN 25 cc. mg. W..F. Baughman: 22%):3:,. $i: ic sees Botte ser ee 96.1 95.8 JAW Sales. a2haslevess: dees Meee eee eee 97.1 97.7 When it is considered that some of the analysts used this method for the first time, the results obtained are quite satisfactory. The results on manganese by the well-known sodium bismuthate method are very satisfactory. It seems probable that even better results would have been obtained if the portions taken fer analysis had con- tained less manganese. A milligram of manganese, in the form of potas- sium permanganate in 50 cc. of solution, gives a color that is too deep 1920] SALE: REPORT ON WATER 89 for the most accurate comparison with standards. The referee has had considerable experience with this method and personally prefers it to the persulphate method. It is recommended that this method be adopted by the association as an additional official method for manganese with the following change: “* * * filter through an alundum or Gooch crucible containing an asbestos mat which has been ignited, treated with a solution of potassium permanganate and washed with distilled water,” instead of “* * * filter through an alundum or Gooch crucible containing an asbestos mat ignited and washed with potassium per- manganate. When ammonia is determined on a sample of water containing sulphids, it is necessary to modify the official method. Otherwise, the distillate will turn cloudy or black when nesslerized. Im some laboratories, the sample of water containing hydrogen sulphid is acidified, freed from hydrogen sulphid by distillation, made alkaline and the ammonia determined as usual'. In other laboratories, the sulphids are precipitated by lead acetate, cadmium chlorid or another reagent and the ammonia determined either with or without the filtering off of the precipitate. Since it is the general policy of the association to accept only those methods which it has tested, it seemed to the referee worth while to run a series of determinations comparing the different methods of determining ammonia in water containing sulphids before recommending a modification of the official method. Accordingly, such tests were made. R. H. Kellner, formerly of the Bureau of Chemistry, conducted the analytical work under the direction of the referee. The results obtained were as follows: TABLE 3. Determination of nitrogen as free ammonia in water containing sulphid. gQ . m4 ' & R= pA PsA Si 8 3 q g aint lina 2 = NITROGEN AS FREE a|Oa] ) aI = ce. cc. ce. cc ce. mg. mg. mg. faleo Distilled noes Aree c 25.0 | 0.078 | Cloudy PSM lore. oles et lye DiatiMed ct nes. talc 323.5 | 0.078 |Black pre- 2) |) Ge On eee on ... | Acid solution aerated, 1.1 | 0.041 | 0.041 made alkaline and distilled. atevo | TO! |.2. oe ... | Acid solution aerated, 0.9 | 0.036 | 0.034 made alkaline and distilled. aor) LO) | s.3< aie ... | Acid solution aerated, 4.4 | 0.148 | 0.148 made alkaline and distilled. 1 J. Am. Chem. Soc., 1910, 32: 1256. 90 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Tasie 3.—Continued. Determination of nitrogen as free ammonia in water containing sulphid. zg Bs pe 5 = | 5 5 928 20. 288 NITROGEN AS FREE S 2a <8 wa nae eS HYDRO- Ase FS ER Fale} Bo, | BSS gc8 TREATMENT eS 2 Ss | BES |) Cas) Olea OS < s g| a5 | S| ges| ate | get ADDED Bl RE | bo | eon | eee) aes Added {Obtained i oe oe =) a ce. | ce. cc. ce. ce. i aes mg. mg. mg. 6] 5 10 4 “6 ‘ Acid solution distilled, 0.9 | 0.044 | 0.042 made alkaline and redistilled. 7/ 5 | 10 Acid solution distilled, 4.4 | 0.156 | 0.141 made alkaline and redistilled. ull (He |) Gan Acid solution distilled, | 323.5 | 0.086 | 0.081 make alkaline and redistilled. Oy ae) 245) Acid solution distilled, 50.0 | 0.086 | 0.092 made alkaline and redistilled. 10) @. || 23 Acid solution distilled, 25.0 | 0.086 | 0.092 made alkaline and redistilled. 11} 6 | 25 Acid solution distilled, 25.0 | 0.086 | 0.095 made alkaline and redistilled. \. 12] 6 | 25 Acid solution distilled, | 280.0 | 0.116 | 0.120 made alkaline and redistilled. 13| 6 | 25 Acid solution distilled, | 280.0 | 0.116 | 0.113 made alkaline and redistilled. 14! 5 1.0 Distilled without filter- 10.6 | 0.551 | 0.493 ing. Gy 1) 5 0.1 Distilled without filter- 1.1 | 0.067 | 0.069 ing. 16| 5 25.0 Distilled without filter- 25.0 | 0.078 | 0.076 ing. TY sy 25.0 Distilled without filter- 25.0 | 0.078 | 0.078 ing. 18} 5 25.0 Distilled without filter- | 280.0 | 0.108 | 0.121 ing. 19| 5 25.0 Distilled without filter- | 280.0 | 0.108 | 0.112 ing. 20; 5 0.1 Distilled without filter- 0.9 | 0.037 | 0.057 ing. Pl ||) 1.0 Distilled without filter- 9.3 | 0.294 | 0.278 ing. 22a\hao 0.1 Filtered and distilled... . 0.9 | 0.0387 | 0.221 238i 25 1.0 Filtered and distilled... . 9.3 | 0.294 | 0.421 24) 5 40.0 Distilled without filter- 25.0 | 0.078 | 0.088 ing. PAS || Bs 40.0 Distilled without filter- 25.0 | 0.078 | 0.096 ing. 26) 5 40.0 Distilled without filter- | 280.0 | 0.108 | 0.141 ing. Diao, 40.0 Distilled without filter- | 280.0 | 0.108 | 0.136 ing. 28} 5 37.0 Distilled without filter- | 323.0 | 0.078 | 0.071 ing. 29) 5 15 | Distilled without filter- | 280.0 | 0.108 | 0.123 ing. 30] 5 15 | Distilled without filter- | 280.0 | 0.108 | 0.118 ing. 1920 SALE: REPORT ON WATER 91 In each of these tests 500 cc. of boiled Washington city tap water, containing known quantities of free ammonia, were used. Either the free ammonia in the reagents was determined, and thus accounted for, or the reagents were rendered ammonia-free. The usual precautions of freeing the still of ammonia and of conducting the distillations in a room free from ammonia fumes were taken. The content of ammonia was obtained largely by adding a standard solution of ammonium chlorid to the sample. Tests 1 and 2 show the necessity of some modification of the official method for samples containing sulphid. Tests 22 and 23 show that erroneous results may be obtained by filtering, even though the filter is carefully washed before use with ammonia-free water, as was done in these tests. Tests 3 and 4 give satisfactory results, but the time consumed in aerating (1 to 2 hours) makes the method unduly tedious. Tests 6 to 13, in which the acid solution was distilled, then made alkaline and redistilled, are satisfactory in every way. It was found that a 20 minute distillation sufficed to free the sample of sulphid. It may be mentioned that efforts to recover quantitatively the hydrogen sulphid from the distillate were fruitless. Adding cadmium chlorid to the sample, then distilling without filter- ing, gave almost as accurate results and was less trouble than distilling off the hydrogen sulphid in the acid solution. The use of lead acetate or copper sulphate, however, did not give quite such good results as did the other procedures. It is believed that additional study should be given to the deter- mination of free and albuminoid ammonia in water containing sulphid, particularly as to the effect of the reagent used on the quantity of albuminoid ammonia obtained, before any particular modification of the official method is recommended. RECOMMENDATIONS. It is recommended— (1) That the method for the determination of barium, page 86, be adopted as official. (First presentation of the method for action.) (2) That the method for the determination of manganese, page 85, be adopted as an additional official method. (First presentation of the method for action.) (3) That further study be given to the rapid method for the deter- mination of calcium and magnesium in industrial water, page 84. (4) That further study be given to the determination of free and albuminoid ammonia in water containing sulphids, with a view to modi- fying the official method in this respect. 92 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 (5) That the referee for 1918 be instructed to continue the work on water along the lines suggested in this report, giving particular attention to the selection of methods for determining lead, copper, zinc and tin in waters, and to the calculation of the milligram equivalents of the radicals found in water with a view to their use in the interpretation of water analyses. (6) That the methods listed below, recommended in 1916!, for adoption as official, be adopted as official this year. (Second presentation of the methods for action.) (a) Method for the determination of lithium, potassium and sodium! (b) Method for turbidity, (1) and (2)?. (ec) Method for color, 3 and 4?. (d) Method for odor, 5?. (e) The Schulze-Trommsdorf method for the determination of re- quired oxygen, 22 and 23°. (f) Method I and Method II for dissolved oxygen, 24, 25, 26, 27, 28 and 29+. (g) Method for the determination of specific gravity, 30°. (h) Method for the determination of hydrogen sulphid, 37°. (i) Method for temporary hardness, 70°. (j) Method for alkalinity, 71, 72, 73 and 74°. (k) Method for total hardness, 75 and 76’. (1) Method for permanent or non-carbonate hardness, 777. (7) That consideration be given to the Gutzeit method for the de- termination of arsenic with a view to having it printed in the methods for the analysis of water (as an additional official method). (Second presentation of the method for action.) (8) That the official reduction method for the determination of nitrogen in the form of nitrate® be revised to read as follows: NITRATE NITROGEN. Reduction Method. (For water of high chlorin content.) REAGENTS. (2) Sodium or potassium hydrozid solution Dissolve 250 grams of the purest hy- droxid obtainable in 1250 ce. of distilled water. Add 2-3 strips of aluminium foil, (b), let stand about 12 hours. Concentrate the solution to 1 liter by boiling. (D) Aluminium foil—This reagent should be the purest obtainable. Cut into strips about 10 cm. long, weighing about 0.5 gram. 1 J. Assoc. Official Agr. Chemists, 1920, 3: 522. 2 Assoc. Official Agr. Chemists, Methods, 1916, 35. 3 [bid., 39. 4 Ibid., 40-1. 5 [bid., 41. 6 Tbid., 50. 7 Tbid., 51. 8 Ibid., 38. 1920] NOYES: DETERMINATION OF SOIL PHOSPHORUS 93 DETERMINATION. Place 100 cc. of the sample, or such a quantity as contains 0.1 mg. or less of nitrogen in the form of nitrate, in a 300 cc. casserole. Add 2 cc. of sodium hydroxid solution, (2). Concentrate by boiling to about one-third the original volume. Transfer to a 100 cc. test tube, using nitrogen-free water, diluting if necessary to a volume of about 75 cc. Prepare a blank (preferably several blanks, since the nitrogen impurity in aluminium is often distributed unevenly) by placing about 75 cc. of nitrogen-free water and 2 cc. of sodium hydroxid solution, (2), in a 100 ce. test tube. Place a strip of aluminium foil in each tube. Close the mouths of the test tubes with rubber stoppers connected by means of bent glass tubes with other test tubes containing about 50 cc. of slightly acidified ammonia-free water. These latter tubes serve as traps to prevent the escape of ammonia and at the same time permit free evolution of hydrogen. Allow the sample and blank to stand at room temperature for 12 hours or until reduction is complete, which is usually within 4 hours. Nesslerize the traps. If they show more than a few hundredths of a mg. of ammonia, the sample has probably frothed over, and the de- termination should be discarded. If the traps contain the equivalent of only 1 or 2 ce. of standard ammonia solution each, they should be disregarded. Transfer the sample and blank to a distillation flask, using 250 cc. of ammonia-free water, distil, nesslerize and compare with standards, as in the determination of free ammonia. Subtract the quantity of nitrogen found in the blank from that found in the sample. Calculate to mg. per liter of nitrate nitrogen (NV). No report on soils was made by the referee. TECHNIQUE OF DETERMINATION OF SOIL PHOSPHORUS! By H. A. Noyes? (Agricultural Experiment Station, La Fayette, Ind.). Considerable trouble was experienced in this laboratory previous to 1914 in obtaining reliable phosphorus determinations in samples of a silty clay loam. The official method*, which gives the phosphorus soluble in hydrochloric acid (specific gravity 1.115), did not prove satisfactory. The sodium peroxid fusion method was not adopted because of irregu- larities in the character of the solutions made up from the same and different soils. The fusion methods used in metallurgical work were not chosen because of the many evaporations and dehydrations that are necessary in order to get rid of soluble silica. The amount of phosphorus that would not be dissolved out of ordinary soil, due to the occlusion of the phosphates by the silica as pointed out by Fry*, is believed to be less than the errors made in carrying out fusion methods. The method of Goss*®, with the modifications given here, has proved 1 Presented by C. B. Lipman. 2 Present address, Mellon Institute of Industrial Research, Pittsburgh, Pa. 3 Assoc. Official Agr. Chemists, Methods, 1916, 24. 4J. Ind. Eng. Chem., 1913, 5: 664. SH. W. Wiley. Principles and Practices of Agricultural Analysis. 2nd ed., 1906, 1: 465. 94 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 entirely satisfactory for the determination of the phosphorus variations of soils under investigation in this laboratory. The articles by Robinson!, Rost2, and Peters’ have led to the belief that other workers might be interested in these modifications. METHOD. Place 10 grams (except for muck and peats) of the prepared air-dry sample in a 250 ce. graduated Kjeldahl flask, add 0.7 gram of mercuric oxid and digest by the regular Kjel- dahl method, as for total nitrogen. Add a crystal (about 0.5 gram) of pure sodium nitrate or potassium nitrate to complete the oxidation. When it is partially cooled, add about 200 cc. of water, and when cooled to room temperature, make to volume. The solution is filtered, through a good grade of folded filter, as follows: Shake the Kjeldahl! flask and pour its entire contents on the filter. Pour back the filtrate until it comes through clear. The solid material settles down and soon prevents everything but the clear solution from passing through. Pipette out 25 cc. of the solution into a 250 cc. beaker, and add 15 grams of dry ammonium nitrate’. Heat the solution to boiling, stirring to insure solution of the nitrate. Add, with constant stirring, approxi- mately 30 cc. of ammonium molybdate solution. Place the beaker in a water bath at 60-65°C. for 1 hour. Proceed from this point according to the official method®. The objects sought and attained by this technique are: (1) The use of a representative amount of the soil sample. (2) Uniformity of treatment of all samples not attained in fusion methods. (3) A single speedy operation to remove the organic matter and pre- pare the solution. (4) Conditions for the precipitation of the ammonium phospho- molybdate which may be duplicated. The concentrations of the solutions used and the addition of the dry ammonium nitrate without preliminary neutralization always yield a clean yellow precipitate of ammonium phosphomolybdate. Acknowledgment is made to 8. D. Conner (Agricultural Experiment Station, La Fayette, Ind.) for cooperation in the testing out of this technique. 1 J. Ind. Eng. Chem., 1916, 8: 148. 2 Soil Science, 1917, 4: 295. 3 J. Ind. Eng. Chem., 1915, 7: 39. 4 J. Assoc. Official Agr. Chemists, 1917, 3: 149. 5 Assoc. Official Agr. Chemists, Methods, 1916, 2. 1920) NOYES: DETERMINATION OF MOISTURE IN SOIL 95 DETERMINATION OF MOISTURE IN FIELD SAMPLES OF SOIL}. By H. A. Noyes? and J. F. Trost (Agricultural Experiment Station, La Fayette, Ind.). The amount of field soil to be used for making moisture determina- tions has been left largely to the individual analyst. It is obvious that differences in the structure of soils must bear a relation to the amount of sorting which will occur in the taking and transferring of specific amounts of soil for the determination of moisture. Four different soils were studied—a fine gravel, a fine sand (Wabash sandy loam), a loam (Sioux silt loam), and a black sand, high in organic matter. The structural character of these soils when air-dry is brought out in Table 1. TABLE 1. Steve mechanical analysis of soils. SIZE OF SOIL PARTICLES IN MILLIMETERS SO Less Less Less Less Less Less be TOTAL Over 5 | than5 | than3 | than 2 | than 1.5] than 1.0 |than 0.75 inant 5 over 3 over 2 | over 1.5 | over 1.0 jover 0.75] over 0.5 percent | percent | percent | percent | percent | per cent | per cent | per cent | per cent Gravel...| 20.2 16.3 12.8 13.0 10.3 6.6 12.2 8.2 99.6 Sand.....| 0.0 0.1 0.1 0.1 0.3 0.3 39.5 59.4 99.8 Loam....| 4.0 5:5 Osi 8.5 12.7 8.7 21.5 32.5 99.1 Black 0.0 0.0 0.5 7.4 12.2 14.5 36.7 28.0 99.3 sand. The table shows that the relative proportions of the different sized particles varied considerably in the different samples. Moisture determinations were made on each of these soils when they contained little more than hygroscopic moisture and also when they contained the moisture content found under average field conditions in early spring. A sample of the loam containing an intermediate amount of moisture was also analyzed. The samples were surface soil and were brought to the laboratory in sealed Mason jars. The jars were kept sealed except during the time that portions of the sample were being taken from them. The average moisture content of the four soils under study was de- 1 Presented by C. B. Lipman. 2 Present address, Mellon Institute of Industrial Research, Pittsburgh, Pa. 96 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 termined as follows: The cover was removed from the jar, the spatula inserted and the soil mixed. By means of the spatula, the approximate weight of soil desired was transferred to a weighed dish and the jar was resealed. Triplicate 2, 5, 7, 10, 15 and 20 gram portions of each sample were weighed quickly but accurately to milligrams. The samples were dried to constant weight in a drying oven regulated to run at 102°C.+2°. The average moisture content shown by the triplicate determinations is given in Table 2. TABLE 2. Effect of size of sample on moisture delermination. WEIGHTS OF PORTIONS IN GRAMS oo l Nl “xGe. | ATIONS 2 5 7 10 15 20 25 per cenl|per cent|per cent per cent|per cent per cent|per cent|per cent Gravelly oecds acres 6.13] 5.65] 5.40| 5.78| 5.85] 5.45] 5.90] 5.74] 0.78 Gravel!A 5c. c-25.0| LOO S78 SEO 1296)" ES 7/oaee | ae SOl Ose Sand iB ec eect nel 12.87 | 12.88 | 13.24 | 13.53 | 13.92 | 13.16] .... | 13.27] 1.05 SiiGld. ty GAeaeee Oboe Oe S W034) LS Le LO) 20) Oy ea Levon mala (oan BY. oes eis cress 20.76 | 22.03 | 21.00 | 21.48 | 21.56 | 21.78] .... | 21.43] 1.27 Loam F...............} 10.23 | 10.35 | 10.33 | 10.31 | 10.75 | 10.87] .... | 10.47} 0.64 IDO Vaecaatn aceon 2.87] 3.13] 3.14] 3.25] 3.38) 3.40] .... | 3.19} 0.53 Blackisand Ey-nene 2 seo. 30.78 | 31.52 | 31.46 | 32.12 | 32.05 | 32.21] .... | 31.68] 1.48 Black sand A..........| 1.43] 1.65} 2.10} 2.16] 2.37| 2.47] ....| 2.03) 1.04 | * Denotes field samples. } Denotes air-dry samples. Table 2 shows the following: (1) That the moisture content determined on different weights is not the same. (2) That the average of all determinations made bears different re- lations to determinations made on the same weights of the different soils. (3) That the amount of moisture in the different samples affected the results obtained. Table 3 gives the variations between the triplicate determinations that were averaged to get the results reported in Table 2. The following factors require that the weight of field soil taken for moisture determinations be large: (a) high moisture content; (b) variable proportions of coarse to fine material; (c) tendency of the soil particles to sort out; and (d) change in moisture during weighing (personal factor). It was found advisable to ascertain, by testing, the weights of differ- 1920] NOYES-TROST: DETERMINATION OF MOISTURE IN SOIL 97 TABLE 3. Effect of size of samples on variations between triplicate moisture determinations. WEIGHTS OF PORTIONS IN GRAMS SOIL 2 5 if 10 15 20 25 30 40 (Gene So ad segoseas 1.49} 1.41] 0.45) 0.20} 0.47) 0.38) 0.65] 0.47) 0.09 GravelWAyie: 226-524)... 0:45)/0:36")) 10:40)) \0:13)}, 0:30')), 0:12)}) 52. | 2. | Ake SiG) Sees Reon e eae eeee 1.19 | 0.52} 0.35} 0.31] 0.15) 0.20 Sard li eee Sees eeeeeee 0.05 | 0.10} 0.07) 0.05} 0.01} 0.01 LDC) Dabs ae ele ee 1.43} 1.13] 0.19) 0.82} 0.37] 0.25 ibaa Deepa eee 0.35} 0.16; 0.19} 0.27} 0.06} 0.03 | WeamvAr toy. 2.) neces 3 =; | 0.05) 0.07} 0.08} 0.04; 0.09} 0.05 iBlack'sand Fe... .... .,.'- 0.35} 0.07] 0.68} 0.43} 0.28} 0.11 Black sand A.......... 0.40} 0.31) 0.30} 0.05} 0.12} 0.08 GIES egg eoaen te | 0.64] 0.46} 0.30} 0.26] 0.21) 0.14 | * Denotes field samples. + Denotes air-dry samples. ent types of soil that must be taken to have the moisture results agree to 0.1 per cent. This gives the relation between factor (d) and the others. It was noted that, although different individuals may not decide on the same weight of soil, due to a difference in individual work- ing errors, they obtain the same moisture results when each one uses an amount large enough to make his duplicates check well. SUMMARY. (1) A quantity of field soil weighing less than 10 grams was found to be unsatisfactory for the accurate determination of the moisture present in a soil. (2) The weight of a particular soil necessary for an accurate moisture determination depends on the soil, the amount of moisture present in it, and the technique of the person making the analysis. (3) With all kinds of soil, the optimum amount required varies with the moisture content and physical condition of the soil, and therefore it is necessary to determine the weight of soil which the average analyst should use. J. B. Rather! (Agricultural Experiment Station, Fayetteville, Ark.), submitted a paper on “An Accurate Loss-on-Ignition Method for the Determination of Organic Matter in Soils’”’. 1 Present address, Standard Oil Company, Chemical Laboratory, Brooklyn, N. Y. 2 Ark. Agr. Expt. Sta. Bull. 140: (1917); J. Ind. Eng. Chem., 1918, 10: 439. 98 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 C. R. Wagner and W. H. Ross (Bureau of Soils, Washington, D. C.), presented by title a paper on “A Modified Method for the Determina- tion of Fluorin, with Special Application to the Analysis of Phosphates”. A STUDY IN SOIL SAMPLING. By Writiram Frear and E. 8. Ers (Agricultural Experiment Station, State College, Pa.). The official directions for soil analysis omit all mention of the method of soil sampling, and manuals for the guidance of soil analysts are reticent upon the procedure necessary to secure a sample. Reports of soil ex- aminations discuss as significant small differences in composition, but furnish no data to establish within what limits analytical results vary for different portions of the same soil solution or for different samples of the same soil. In fact, the literature furnishes few data for guidance, and an inquiry, very limited in scope, showed that even those inves- tigators who are directing extensive soil studies, involving large ex- penditure of time and money, are employing sampling methods quite different in detail. The writers made a study which, it was hoped, would give informa- tion as to the precautions necessary to obtain representative samples of the surface soil upon which the general fertilizer series of plats of the Pennsylvania Agricultural Experiment Station are located. The soil is not of a single type, but is chiefly Hagerstown silty clay loam. The problem was, however, to represent the plats studied, not the individual soil types or subtypes. Earlier studies? have shown a marked lack of uniformity as to chemical composition in the soil adjacent to these plats. Concretely, the question was how many subsamples must be taken from well and symmetrically distributed points over the respective plats in order that duplicate composites from the same one-eighth acre plat may agree satisfactorily with respect to the point of composition in question. The plats sampled were Nos. 1 and 4, Tier II, of the series above- named. The samples were taken in July and August, 1916, in three sets: I and II, by Erb and Kern, for one study; ILI, by G. J. Kuhlman, for another study. The sets differed in the following respects: 1 J. Ind. Eng. Chem., 1917, 9: 1116. ‘ 5 Report of the Pennsylvania State College, 1908-1909, 215; 1909-1910, 163; 1910-1911, 13. Sa demas ce soe. 1920) FREAR-ERB: A STUDY IN SOIL SAMPLING 99 Set I—Taken by excavation of holes 9 x 4 inches to subsoil (3-8 inches; average, 63 inches). Excavations, 11 to the series, taken in zigzag lines crossing the plat from side to side, beginning at the Northwest end and concluding at the Southwest end. Series A includes the excavations begun at the West corner of Plat I; Series B, those beginning at the North corner of that plat; Series C and D, the corresponding excavations for Plat IV. The subsamples from the excavations were weighed, air-dried, weighed and prepared separately for analysis, but only the corresponding fine soils (passing a sieve of 2'v inch mesh) were used in aliquot portions to make up series composites for analysis. The individual subsamples weighed from 2.25-5.75 kg. each, after air-drying. Set I1—Taken by borings with a i inch soil auger, using only the surface soil thus removed from each boring. The series in this set were lettered E to H, and correspond in distribution to the respective series, A to D, above described. Each series represents 40 borings, which were composited as they were taken. Weights of composites, air-dry, 4.5-4.9 kg. Set I1I—Taken and composited in the same manner as Set II, but distributed along the lines of an X over the respective plats, 64 borings to the plat. Series I in- cludes the borings from Plat I; Series J, those from Plat IV. All the results are based upon the air-dry soils, whose hygroscopic moisture content ranged from 0.72 to 0.95 per cent. The difierence would affect only the acre weight determinations and these in amounts within the limits of error of the determinations. ACRE-~7 INCH WEIGHTS. The acre-7 inch weights, calculated from the results obtained by the excavation method, with the correction described in the following paper’, afford the following data. The computations were based upon apparent specific gravities for soils to the average depth of 63 inches. A slight, but nearly uniform error is thus introduced. TABLE 1. Surface soil acre-7 inch weight (corrected). PLAT SERIES SERIES AVERAGES DIFFERENCE PLAT AVERAGES pounds pounds pounds iz A ZL OBZ 0309 |) a ecectch ss Spel || lee ornare eis I B 2,101,293.2 19,262.3 2,091,662.0 IV Cc CAPPED | Bat serene Umar) Mics air aa) IV D 2,046,923.5 20,958.0 2,036,449.1 ELEC GUiREY are 22 See a cae oor Bed 5 EON SEP ae ies Se nee ae ee 55,212.9 The probable error of these apparent specific gravity determinations, computed by the use of the Gauss formula, rarely affects the results to more than the third decimal place. Expressed in pounds to the acre-7 1 J. Assoc. Official Agr. Chemists, 1920, 4: 103. 100 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 inches, the probable errors of the single series of eleven subsamples each range from + 9,300 pounds to + 15,500 pounds, and for the twenty-two determinations to the plat, from + 8,700 pounds to + 9,800 pounds. The differences between series were therefore distinctly larger than the probable errors of the determinations. The extreme range of apparent specific gravity found for single subsamples (1.209 to 1.425) emphasizes the importance of the duplication of such determinations. FRACTIONING THE SAMPLES. The excavated subsamples were so large that, to save labor, their fractioning or parting before sifting out the fine soil was highly desirable. The accuracy of the usual simple parting method was first tested. The air-dry soils from two subsamples were rolled on an oilcloth fifty times, the fine soil was brushed radially to the central heap, the latter quartered, and each quarter pestled with a rubber pestle and sifted separately. The following results were obtained: TABLE 2. Mechanical analyses of subsample quarters. DESCRIPTION OF SAMPLE COARSE* MEDIUM FINEt Subsample B;: per cent per cent per cent First quarterso7e nen eee 7.41 7.97 84.52 Second! quarters .ca. sacar teecee 3.51 2.07 94.42 Shhird quarters s5-see Reece 5.77 7.46 86.73 Rourthiquarter: eee ene 6.37 6.47 87.16 Subsample Bz: First quarter Fre, .cocaccc cece 2.99 2.45 94.56 Second quarters. oe eee 2.38 1.76 95.86 Phicd quarters sacs eee eee 2.05 1.54 96.41 Rourthiquarteny... 5 eee eee 3.11 2.67 94.22 * Left on 3 mm. sieve. + Left on 3, inch sieve. } Passed »'; inch sieve. This method of mixing evidently failed to secure a uniform distri- bution of the larger particles through the aliquots. Probably no serious difference in the mechanical groups of the fine soil would have resulted from its use, but the gravel component might be very considerably affected. Since this point was of importance in the present study, the entire amount of each subsample was sifted. 1920] FREAR-ERB: A STUDY IN SOIL SAMPLING 101 SIFTING RESULTS FOR PLATS I AND IV. The results from the sifting of the two lots of subsamples follow: TABLE 3. Mechanical analyses of the whole sample. SAMPLE NUMBER AND DESCRIPTION pence Preis (os per cent per cent per cent Plat I: Series A, excavation............. 4.45 5.90 89.65 Series B, excavation............. 4.70 4.18 91.12 Plat I: Average of 22 subsamples........ 4.57 5.04 90.39 Series E, 40 borings.............. 3.42 5.49 91.09 Series F, 40 borings.............. 2.36 3.55 94.09 Plat I: Average of 80 borings ........... 2.89 4.52 92.59 Series I, 64 borings.............. 7.03§ Save 92.97 Plat IV: Series C, excavation............. 4.71 4.05 91.24 Series D, excavation............. 3.90 4.16 91.94 Plat IV: Average of 22 subsamples........ 4.31 4.11 91.58 Series G, 40 borings............. 2.50 4.50 93.00 Series H, 40 borings............. 3.53 3.51 92.96 Plat IV: Average of 80 borings............ 3.02 4.00 92.98 Series J, 64 borings.............. 7.00§ ot: 93.00 * Left on 3 mm. sieve. + Left on 3, inch sieve. t Passed =\; inch sieve. § Coarse and fine combined. COMPOSITION OF FINE SOIL. Differences of the magnitude reported above must obviously affect the weight of fine soil found for a particular area and depth. Whether the chemical composition also of the fine soil is similarly affected re- mains to be considered. The respective fine soils (series composites, in most cases) were separately analyzed, usually in duplicate, with respect to a number of the constituents. The nitrogen and phosphoric acid for all samples, and 102 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 the loss on ignition for Set III samples, were determined by Walter Thomas; all the other determinations were made by E. S. Erb. The results, together with the year of analysis, are presented in the follow- ing table: TABLE Composition (Air-dry basis SETI DETERMINATION YEAR Series A Series B per cent per cent Elygroscopic:molstures-.).cistes < ssniei sie oie Ge eee 1916 0.894 0.792 1917 0.950 0.720 Loss Onl ignition s:. ..)5.¢ 22.05 s -aeiweesee Deaton 1916 4.532 4.532 1917 Dry matter lostionsenitiona...4 ee oes eee eae 1916 3.638 3.740 INitrogen: iio. Sane tee ee aren reer eee ERR 1917 0.101 0.1055 Potassium‘oxid) total (Smith) c-eece 3 eee eee 1916 3.799 3.918 Potassium oxid, soluble in hot hydrochloric acid (1.115 sp: gr:); LO thoursis.2\verdece dene teem ae ee 1916 0.3687 Potassium oxid, soluble in N/5 hydrochloric acid, 40°C., SOUS. esp ae a ee een ae: 1916 0.0140 | 0.0136 Phosphoric acid, soluble in N/5 nitric acid, 40°C., 5 hours. 1916 0.0020§ * Recalculated to 0.95 per cent moisture basis. + Recalculated to 0.82 per cent moisture basis. All of these samples represent unusually large amounts of soil taken, an unusually large number of subsamples, and subsamples distributed with care, probably greater than usual; also, no error in parting or quart- ering the samples is involved in the case of Sets I and II. In contrast with these, each series of Set III represents, on the one hand, a greater number of subsamples than was used for the series of Sets I and II; but, on the other hand, a somewhat different distribution of subsamples and a mode of quartering that the writer’s later work has shown to be inade- quate for the purpose of a mechanical analysis. Comparison of the respective series results for Sets I and II, shows that, despite unusual care, the sampling error remains greater than the analytical error. The series averages from the boring samples, Set II, agree as well with one another as do those obtained by excavation; —~ 1920) FREAR-ERB: APPARENT SPECIFIC GRAVITY OF SOILS 103 hence the one method represents the composition as well as the other. The importance of careful distribution of subsamples and preparation of composites is shown by the differences in results for the samples of Sets IT and IIT. 4, of fine soils. averages.) SET II SET 01 j SETI SET I SET UI Series E Series F | Series I Series C Series D | Series G | Series H Series J per cent per cent per cent per cent percent | percent per cent per cent 0.792 0.785 cect 1 ofl iOsgon 1.088 | 0.875 0.864 0.950 0.950 | 1.35 0.850 0.820 0.820 0.870 1.50 4.733 HEM) || Gece 4.967 4.867 | 4.970 4.867 a 5.666* see eee Pee eee 6.1207 3.941 3.894 4.716* 4.176 3.779 | 4.150 3.797 5.3007 0.109 0.1075 0.1000* | 0.100 0.103 | 0.109 0.1005 0.1022T 3.891 3.678 eet oet [Es 495 3.596 3.496 3.585 | 0.4074 0.4067{ 0.0146 0.0150 | stzters 0.0310 0.0303 | 0.0295 0.0294 0.0018§| .... | 0.0019§| 0.0021g} .... | 0.00238) .... 0.0031§ t Represents average of different sets of heatings. § Represents grand composite for the set. EXCAVATION METHOD FOR DETERMINING THE APPARENT SPECIFIC GRAVITY OF SOILS. By Witu1am Frear and E. S. Ers (Agricultural Experiment Station, State College, Pa.). Various methods have been proposed and used for determining the apparent specific gravity of soils. They may be divided into two classes: First, those in which, by means of a tubular or prismatic implement with a cutting edge, a block of soil of definite cross-section and depth is separated and removed from the body of the soil; second, those in which the measured block of soil is separated from the surrounding soil by trenching, is shaped to exact dimensions in place, and, with or with- 104 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. 1V, No. 1 out coating to preserve its integrity, is cut off at the desired depth and removed for weighing. Many cautionary measures have been given to secure a high order of exactness for the determination. These methods are open to two serious objections. They are suited only to fairly homogeneous soils of fine texture. If the soil is composed in considerable part of gravel, or if it contains larger fragments of stone, cutting tubes or prisms can not be driven into the soil without dis- turbing its normal texture, and blocks of correct form and plane sides can not be secured for weighing. Second, these methods are so laborious that they can not well be used for repeated determinations made on the same soil to check against errors arising from variations in its uniformity of texture. For use in a soil through which flinty fragments, of one or more inches or greater diameter, are irregularly but rather frequently scattered. the writers have therefore adopted a method quite different in principle from those of the classes above-mentioned. By this method, the soil is broken and removed from a roughly measured space and weighed before and after air-drying. The volume of the space from which the soil has been removed is measured by careful determination of the volume of dry sand required exactly to fill it. From the data for soil weight and excavation volume, with any necessary correction for change in the volume of the sand resulting from its transfer from the graduate to the excavation, the apparent specific gravity can be computed. ~ The following details have been employed in the use of the method: (1) The soil was examined at a time when it was fairly dry, but sufficiently moist not to crumble too readily. (2) The surface was cleared of stubble and smoothed by use of a sharp trowel or knife. (3) By means of a rule and a knife, a rectangle was marked off upon the smoothed surface. For the soils studied, the dimensions 9 x 4 inches were chosen, so that suffi- cient space for the use of excavating tools might be secured. For coarser soils, larger excavations would be preferable. ==": (4) Two straight-edged pieces of wood were laid parallel, close to and on opposite sides of the lines marked on the surface, and a vertical cut 2 or 3 inches deep was made by use of a sharp knife or flat trowel. A helper kept the pieces of wood firmly in place during the cutting, and the trowel was withdrawn very carefully to avoid any displace- ment of the surface soil. (5) The soil within the excavation was then removed by aid of a narrow trowel and transferred to a receiver. A piece of oil cloth was spread between the edge of the ex- cavation and the receiver so as to catch and preserve any soil particles that might spill. The excavation was continued to approximately the desired depth by the use of a knife or trowel, in such manner as to leave undisturbed such of the larger stone frag- ments as were firmly fixed in the walls of the excavation, but so as to remove with the soil other fragments that came away loosely from the sides or bottom. (6) The soil thus removed was promptly air-dried. (7) The volume of the excavation thus made, was determined by filling it with sand 1920] FREAR-ERB: APPARENT SPECIFIC GRAVITY OF SOILS 105 from a graduated cylinder. The sand was delivered uniformly by pouring from a height of 2 or 3 inches above the surface and along the major axis of the rectangle. From time to time as the filling proceeded, the central ridge of sand, formed in the manner described, was leveled and filled into the corners of the excavation and into the hollows in its sides that were caused by the breaking of stone fragments. This leveling and dis- tribution was accomplished by means of a straight-edge, with which the sand was stroked as gently as possible to avoid unequal compression. Care was taken to deliver the last portions of the sand a very little at a time, so that no excess might in any case be used for the filling. (8) To reduce as far as possible the error in the measurement of the sand, which was free from all but traces of loam, the liter cylinder was filled each time in precisely the same manner. The sand was delivered into a small funnel, set in the neck of the cylinder. When filled almost to the mark, the sand was leveled by gently rocking the cylinder without jarring it. The last portions of sand required were then allowed to trickle in from the hand. (9) To secure the highest practicable exactness of measurement, the sand remaining in the large cylinder after the excavation was filled, was transferred in like manner to a 50 cc. cylinder to determine its volume. (10) Finally, to determine what correction, if any, was necessary for a difference in the space occupied by the sand in the measuring vessel and in the excavation, a standard cylindrical brass half-peck measure (4409 ce.) was repeatedly filled with sand in the same manner in which the soil excavations were filled, and from the liter cylinder em- ployed in the field measurements. The excavations were carried down to subsoil, which was found at depths varying from 3 to 73 inches. The uncorrected volumes of the excavations ranged from 1658 to 4552 cc., with an average of 3467 cc. The depth of the measure was therefore approximately that of the average excavation. The quantities of sand severally required for 10 fillings of the half-peck occupied on the average 4459 = 0.77 cc. in the glass graduates; that is, the sand was less compact in the half-peck in the proportion 4409 : 4459 = 0.77 or as 1000 : 1013. The measures obtained as the volumes of the excavations were therefore divided by the factor 1.013 to correct for the relatively greater compactness of the sand in the measuring cylinder. In the use of this method, it is necessary to determine the correcting factor corresponding to the fillmg material used and the conditions of filling maintained in each series of studies. The labor thus required is not great. On the other hand, the excavation can be made and its volume determined in little more than an hour, so that duplications of the determination at various points of the surface in question can easily be made. The importance of such duplication will be discussed in an- other paper. 106 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 NITROGENOUS COMPOUNDS IN SOILS'. J. K. Ptummer (State Department of Agriculture, Raleigh, N. C.), Associate Referee. The work outlined this year has been a continuation of that done by C. B. Lipman?, the plan of which follows: PLAN OF WORK. The problem was to test out on the same material the official Kjeldahl method for nitrogen determination in soils*; the official method, as given under “‘Fertilizers’’*; and the Hibbard method for nitrogen deter- mination in fertilizers, as modified by C. B. Lipman for soils. HIBBARD MODIFICATION OF THE GUNNING METHOD. Place the soil in a 500 ce. or, better, in a 800 cc. long-necked Kjeldahl digestion flask, add 30 cc. of sulphuric acid and approximately 10 grams of a mixture prepared by grinding together and thoroughly mixing 10 parts of potassium sulphate; 1 part of ferrous sulphate; } part of copper sulphate. Immediately shake the mixture of acid, salt and soil so that no soil remains untreated by the acid. Then digest it, first with a low flame, and then with a strong flame for 13-2 hours, depending on the amount of organic matter present. After digestion, dilute the mixture, transfer it to 1 liter copper distillation flasks, and distil into N/10 hydrochloric acid. Titrate the acid in the usual way, using either methyl orange or cochineal as an indicator. METHODS TO BE TESTED. (1) Official method under “‘Soils’’®. (2) Official method under “‘Fertilizers’’*. (8) Hibbard modification of the Gunning Method. SPECIAL INSTRUCTIONS. Try all of these methods on each soil as follows: Ten gram portions of soil (20 cc. of sulphuric acid). Twenty gram portions of soil (30 cc. of sulphuric acid). The period of digestion should be 2} hours in every case. Use methyl orange or cochineal as indicator. Take special care in neutralizing the acid before distillation. Preferably employ Greenbank’s lye and make up by dissolving 1 part in 2 of water. Jse N/20 hydrochloric acid amd N/20 ammonium hydroxid, or N/20 sulphuric acid and N/20 sodium hydroxid. Report the results in terms of cc. of acid, in mg. of nitro- gen, and in per cent of nitrogen in air-dried or water-free soil. Samples of Durham sandy loam (1 A) and Iredell loam (2 A) were washed free of nitrates. To portions of the original Durham sandy loam 0.02 (1 B) and 0.04 (1 C) per cent nitrogen, as sodium nitrate, was added. Portions of the original Iredell loam were similarly treated and the results appear in the table as 2 B and 2C. All samples were oven-dried before being sent out. The following table gives the results obtained: 1 Presented by C. B. Lipman. 2 J. Assoc. Official Agr. Chemists, 1920, 3: 326. 3 aa Official Agr. Chemists, Methods, 1916, 21. 4 Tbid., 8. 1920] PLUMMER: NITROGENOUS COMPOUNDS IN SOILS 107 Comparative results of nitrogen delerminations. (Nitrogen expressed as per cent.) SAMPLE E. F. BERGER* GEORGE WIBLE* P. P. PETERSONT S. LOMINETZ{ Method Method Method Method Number) Weight 1 2 3 1 2 3 1 2 3 1 2 3 grme|| cent \i cent, | centia| cente | cenb |vecnt || cent | cent | cent \|\ cent | cont! | cept 1A | 10 |0.029|0.027\0.030/0.028}0.027\0.028/0.028/0.031|..... 0.017/0.015)0.025 HAT |/220)10%02710..025)0. 0272.22 ec 2 woe. a 0.028/0.032/0.028)/0.021/0.025)/0.019 1B | 10 |0.027/0.026)..... 0.027|0.025/0.029/0.022|0.029)..... 0.026/0.033,0.038 ESP ZO" |OLOZG|OL O26). 52a] hea. al fee, ters oer aimereetey ers «os 0.025/0.029}..... 0.032 1C | 10 |0.047\0.059\0.046/0.050)0.059,0.046/0.053)0.059)..... 0.015/0.022\0.025 G20) 10) 04:7/02052102046]. Saas ee eee OFO63tR5.... 0.042/0.020/0 .026/0 .023 2A | 10 |0.037/0.036\0.037/0.039/0.037\0.039\0.032/0.043)/0.037\0.033/0.046)0.039 PN A 0 oe OROSTIOROS5IRee bali. center 0.039)..... 0.034/0.041/0.054/0.040 2B | 10 |0.034/0.037\0.039)0.039/0.037\0.038,0.039/0.045|..... 0.027/0.041)0.043 ZBa 20) 102037102 086)0 oie Seer. ie. ok 0.039)0.036)0.039|0.032|0.038)0.031 2C | 10 |0.053/0.061/0.061\0.057/0.058/0.054\0.058/0.063)... . . 0.041/0.054|0.048 eee 20 ON052/05002|OFO5G| eae | bee 0.057}... . .|0.052/0.043/0.068)0.045 * Agricultural Experiment Station, E. Lansing, Mich. + Agricultural Experiment Station, Moscow, Idaho. } Agricultural Experiment Station, College Station, Texas. CONCLUSIONS. After a careful examination of the results obtained by the different analysts, it does not appear wise to offer any recommendation for the adoption of a new method to supplant the present official method. However, the results clearly show that there is little choice between the methods now in vogue for measuring small amounts of nitrogen in soils. The official method to include nitrates does not recover the nitrogen which has been added in the form of sodium nitrate. Sometimes this method gives higher results than the other modifications tested, and sometimes not so high. Taking the results as a whole, the Hibbard modification gives about as high figures as either of the other two methods. Considering the ease of manipulation of digestion and distillation, the Hibbard method seems to be preferable. Nitrates should be determined on another sample by either the colorimetric or reduction method. No consistent difference is apparent whether ten or twenty grams of soil are taken for analysis. 108 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 REPORT ON THE LIME REQUIREMENT OF SOILS. By W. H. MacIntire (Agricultural Experiment Station, Knoxville, Tenn.), Associate Referee. The work outlined upon the problem of lime requirement has been along two lines: (1), an effort to ascertain the conceptions and view- points held by those who have given particular attention to the problem with a view to defining the term “Lime Requirement’’; (2), a study of one or more representative types of the several procedures advanced. It is well known to the members of this association that there exists a marked diversity of opinion as to the nature of the phenomenon causing the decomposition of calcium carbonate applied to soil. By some it is held that true, if peculiar, acids occur in soils, the hydrogen ion concentration of which may be determined. Others hold that the de- composition of carbonate is effected through physical absorption of the calcium ion, while a third conception is that the original basic silicates have undergone hydrolysis with subsequent leaching of the hydrolyzed products, thus leaving a complex mixture of what may be considered as true acid silicate salts. It has been hoped first, to reach an agreement as to the terminology; second, to arrive at some definite conclusion as to what may be demanded of a method and what procedure most nearly fulfills the exactions decided upon and, furthermore, as to whether the procedure should be considered solely as a laboratory measurement of a physical or chemi- cal phenomenon or whether the chemical data should be susceptible of interpretation into field practice. This, of course, involves the question of the possibility of correlating lime absorption measurements with plant response. This again raises the questions of pot studies v. field studies: selection of plant indicators; purity; hardness; porosity and solubility; and proper time for, and frequency of, application. Most of these considerations involve both the chemical and biochemical factors direct and indirect, as well as the economics of the problem. To quote aptly, B. L. Hartwell, in correspondence with the associate referee, writes as follows: It seems to me that what we need is a definite criterion of what we are attempting to accomplish, by which we may judge of the merit of the rather confusing number of methods. The acquiring of more data without some definite standard is, I fear, untikely to mean an advance. * * * It seems to me that we must ask the question —lime requirements for what? For what kind of a crop? And requirements for how long a time, ete.? Queries as to the advisability of the utilization of pots have developed the fact that by many it is held that this method may be considered 1920) MACINTIRE: LIME REQUIREMENT OF SOILS 109 as indicative only. It has been observed by some that the mechanical preparation and handling incident to pot studies often produce an effect upon plant growth analogous to that produced by liming, so that some soils which respond to liming under field conditions fail to show a similar response or an equivalent response in pot studies because of the abnor- mality of the checks. There also arises a number of considerations under field conditions which make the study of lime requirement an efiort somewhat beyond the scope of this association. The amount and nature of initial soil components affected by treatment; the amount of carbon dioxid gen- erated within the soil and the tendency of different soils to vary in the retention of this gas; soil type; plant adaptability; rainfall; and prob- ably most important of all, the time factor, militate against extensive field studies. As a matter of fact, it is held by many that such a move would be a digression from the proper scope of the work of this asso- ciation. While the possibility of cooperation with some organization such as the American Society of Agronomy has been suggested, it is maintained by some that such a course would not be feasible or ad- visable. The economic phases of the problem are, in the final analysis, usually dependent upon local conditions and the recommendations advanced would most probably be based upon field trials rather than upon quan- titative laboratory data. On the other hand, it is of great interest in studying soils under laboratory conditions to determine the lime absorp- tion coefficient as a part of the laboratory inventory of a soil’s compo- sition or tendency toward reactions of various kinds. It is, however, to be admitted that in some cases indications of a tendency to absorb lime is not conclusive proof of the need of lime under field conditions. The fact that soil will decompose applied calcium carbonate is not positive proof of the lack of an abundance of calcareous silicates which may so readily yield to hydrolysis as to insure a sufficiency of lime to maintain a nutrient soil solution of alkaline reaction, i. e., if calcium bicarbonate solution be considered as alkaline. lt is suggested that, for the present, the determination of the lime requirement of a soil be considered solely as a laboratory procedure, adopted to measure the amount of lime absorbed by a soil under uniform conditions to be set forth in such a method as may be later adopted. It is further suggested that, as a preface to the statement of the details of the technique which may be later adopted, it should be stated that the procedure is intended and considered solely as a laboratory procedure supplementary to the determination of the chemical compo- sition of the soil and that no correlation with practical or economic usage is intended or implied. 110 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 INVESTIGATION OF METHODS. This work has consisted of studies of representative types of procedures. It was intended that a study of the several methods should be individual rather than comparative. In other words, instead of a quantitative comparision between methods, each method was used as its own cri- terion by which to judge the subsequent indications obtained by the same method. The plan was as follows: The lime requirement indication for each soil was determined and the amount of calcium carbonate so indicated was applied in the form of carbon-dioxid-treated precipitated carbonate. The applications were made to the air-dry soil and thoroughly mixed, after which the soils were placed in stoppered bottles and wetted to a good condition. After about 48 hours contact, one set was permitted to dry spontaneously. A second set was kept under anaerobic condition for two weeks, while the third set was kept for a month or more. The dried soils were again thoroughly mixed and the lime requirements obtained. The methods selected were as follows: The Jones and Hopkins methods, as representative of the neutral salt solution treatments; the Veitch method; the electrometric procedure advanced by Sharp and Hoagland; the lowering of the freezing point method of G. J. Bouyoucos; and the Tacke. and MacIntize procedures, involving treatment with distilled water and carbonated water solutions of calcium carbonate, respectively; and the hydrogen ion colorimetric method advanced by L. J. Gillespie. SOILS USED. The work reported by L. T. Sharp and D. R. Hoagland, G. J. Bouyoucos, L. J. Gillespie and your referee was carried out upon -ten soils collected by F. P. Veitch, the previous referee. The following descriptions of the soils were furnished by Veitch: L. § P. No. 32347. This sample was obtained from the Pennsylvania Agricultural Experiment Station, tier 2, plat 35. The sample was taken May 29, 1916, and at that time bore a thick, dark colored, well-developed stand of red clover. According to our tests, this soil is decidedly basic, both to phenolphthalein solution and red litmus paper, when allowed to stand 14-18 hours in contact with water. When allowed to stand 2 hours before filtering and making the determination, the soil is acid or neutral to phenolphthalein and very faintly basic to red litmus paper. L. § P. No. 32348.—This sample is also from the Pennsylvania Agricultural Ex- periment Station, tier 2, plat 26. The sample was taken May 29, 1916, and, at the time, bore a thick, light-colored but poorly developed stand of red clover. The soil was neutral or faintly basic to phenolphthalein solution when allowed to stand 14-18 hours. It was faintly basic to red litmus paper. When allowed to stand but 2 hours, the soil was acid both to phenolphthalein and red litmus paper. L. § P. No. 32349.—This sample was from the Pennsylvania Agricultural Experi- ment Station, tier 2, plat 6. It was taken May 29, 1916, and, at the time, bore a thin 1920] MACINTIRE: LIME REQUIREMENT OF SOILS 111 stand of red clover. Reaction when allowed to stand 14-18 hours: to phenolphthalein, basic; to red litmus paper, basic; when allowed to stand 2 hours: to phenolphthalein, acid; to red litmus paper, faintly basic. L. § P. No. 32350.—This sample was from the Pennsylvania Agricultural Experi- ment Station, tier 2, plat 31. It was taken May 29, 1916. “Practically no red clover.” Reaction when allowed to stand overnight: acid to phenolphthalein and red litmus paper. L. § P. No. 32351—This sample was from the Pennsylvania Agricultural Experi- ment Station, tier 2, plat 32. It was taken May 29, 1916. “No clover has grown on this end since 1908. All crops fail and only sheep sorrel, red tops and foxtail grow.” Reaction acid to phenolphthalein and red litmus paper. L. § P. No. 32352—This sample was from the Rhode Island Agricultural Experi- ment Station, plat 23. It was taken during the summer of 1916. Reaction to phenol- phthalein when allowed to stand 16 hours, acid; to red litmus paper, acid; and to blue litmus paper. acid. L. § P. No. 32353—This sample was from the Rhode Island Agricultural Experi- ment Station, permanent plat 25. It was taken in the summer of 1916. Reaction on standing 16 hours: to phenolphthalein, acid; to red litmus paper, neutral. L. § P. No. 32355.—This sample was from the Rhode Island Agricultural Experi- ment Station, permanent plat 29. It was taken in the summer of 1916. Reaction when allowed to stand 14-18 hours: to phenolphthalein, basic; to red litmus paper, basic. Reaction when allowed to stand 2 hours: to phenolphthalein, acid; to litmus paper, faintly basic. L. § P. No. 32361—This sample was from W. H. MaclIntire, Cornel! University. “Surface soil clover field north of red barn, Dunkirk silt loam. Red clover, alsike and timothy. Limed some years ago, quite heavily. Distinctly acid to litmus paper tested moist in field.” Reaction when allowed to stand 14-18 hours: to phenolphthalein, basic; to red litmus paper, basic. When allowed to stand 2 hours: to phenolphthalein, basic; to red litmus paper, basic. L. § P. No. 32819.—This sample was from College Park, Md., uncultivated since 1888, frequently burned over since that time. Vegetation plantain, sedge, hen grass, briers, some vetch. Have never seen clover on it in 20 years. Reaction when allowed to stand 14-18 hours: to phenolphthalein, acid; to red litmus paper, faintly basic. L. § P. No. 32820.—This sample was from flat land, College Park, Md. Frequently cultivated in the past 20 years but not in the past 3 years. Last put in corn, now over- run with weeds, plantain and briers; no clover. Reaction when allowed to stand 16 hours: to phenolphthalein, acid; to red litmus paper, basic. As determined by Veitch, five of these soils were acid and five were alkaline to distilled water extractions run as blanks to the Veitch procedure. The indications obtained in using the other six methods were that each of the ten soils was acid in character. In this connection, it might be stated that it is the firm conviction of Veitch that there exists no need of liming in practice in the case of soils which yield an alkaline distilled water extract. In detail, the reactions were as follows: 112 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 TABLE 1. Qualitative reactions of the soils studied as indicated by the several procedures. PROCEDURES FOLLOWED & - ; 2 | gee] 3 $ z TYPE OF SOIL = ie ES Se a z 3 I ese | va 3 cee 8 S 25 5) g a lie RN ae F(c mp M | | os 32347 | 1 | Very fine sandy loam...... Alkaline | Acid | Acid | Acid | Acid | Acid 32348 | 2 | Sandy clay loam.......... Alkaline | Acid | Acid | Acid | Acid | Acid 32349 | 3 | Very fine sandy loam...... Alkaline | Acid | Acid | Acid | Acid | Acid 32350] 4 | Sandy clay loam.......... Acid Acid | Acid | Acid | Acid | Acid 32352 | 5 | Sandy humus loam........ Acid Acid | Acid | Acid | Acid | Acid 32353 | 6 | Very fine sandy humus loam | Acid Acid | Acid | Acid | Acid | Acid 32355 | 7 | Fine sandy humus loam....| Alkaline} Acid | Acid | Acid | Acid | Acid 32360) 183 Mout oamniaene sere alia Alkaline} ... | Acid | Acid | Acid | Acid 32819] 9 | Fine sandy loam.......... Acid Acid | Acid | Acid | Acid | Acid 32820) 107 |;Sandy loam =. o-— 45-5 Acid Acid | Acid | Acid | Acid | Acid HYDROGEN ION CONCENTRATIONS AND ELECTROMETRIC INDICATIONS OF LIME REQUIREMENT. The ten samples collected by Veitch were sent to Sharp and Hoag- land, University of California, Berkeley, Calif., who made separate determinations, the averages of which are given in Table 2. To quote: TABLE Hydrogen ion concentration of HYDROGEN ION CONCENTRATION HYDROGEN ION CONCENTRATION ORIGINAL SOIL* OF TREATED SOIL AFTER PURE 16 DAys CALCIUM L. & P. CARBONATE No. ADDED TO Kept moist Gram mols 100 GRAMS per liter Pat OF SOUL saat ae Pu 32347 0.12x10-5 5.92 0.137 0.92x10-7 7.04 32348 0.27x10-® 5.57 0.156 0.11x10-§ 6.96 32349 0.13x10-8 5.89 0.064 1.00x10-7 7.00 32350 0.19x10-4 4.72 0.285 0.12x10-§ 6.92 32352 0.33x10-4 4.49 0.446 1.00x10-7 7.00 32353 0.36x10-5 5.44 0.267 0.12x10-5 6.92 82355 0.37x10-§ 6.43 0.059 0.50x10-7 7.30 323861 1.00x10-7 7.00 0.000 0.11x10-§ 6.96 32819 0.32x10-5 5.45 0.096 0.67x10-7 aud 32820 0.24x10-5 5.62 0.095 1.00x10-7 7.00 * Measured in suspensions of 10 grams of soil to 30 cc. of water. + Neutral point taken as 0.8x10-? Py 7.10. 1920] MACINTIRE: LIME REQUIREMENT OF SOILS 113 The hydrogen ion concentrations were determined in all cases in suspensions of soil in the proportion of 10 grams of soil to 30 cc. of water. The attainment of equilibrium was hastened by the shaking method. * * * The amounts of calcium hydroxid necessary to bring the soils to a neutral reaction were determined independently, as in the case of the hydrogen ion concentrations. Closely agreeing results were obtained and the averages of both are recorded in the table, expressed as grams of pure calcium carbonate necessary to neutralize 100 grams of air-dried soil under the experimental conditions. Titrations were made on 5-gram samples, using a standard calcium hydroxid solution. The time of titration was extended over several days, with shaking at inter- vals. The equivalent amounts of precipitated calcium carbonate were added to 100- gram portions of the soil and thoroughly mixed. The soils were then brought to an approximate optimum moisture content and again mixed. One-half of the total quan- tity of each soil was allowed to dry spontaneously; the rest was kept moist. The hydrogen ion concentrations of both sets were determined after 16 days and after 38 days. After 16 days the soils were in practically neutral condition, as shown in the table. At the end of 38 days, the soils were still close to the neutral point, but, in the majority of cases, a slight but distinct increase in the hydrogen ion concentration was noted. * * * Inorder to determine the quantity of calcium carbonate necessary to neutralize all of the soil acids present, it would be necessary to continue the titra- tion over a longer period of time, or perhaps employ heat. As a matter of fact, the method of treatment actually carried out, that is, a titration with calcium hydroxid covering a 3-day period, was more intense than any of the other procedures followed. In view of the foregoing findings, Hoagland wrote that he deemed it unnecessary to make determinations of possible residual carbonates. This, however, was done by the writer in studying the Tacke and the MaclIntire pro- 2: untreated and treated soil. HYDROGEN ION CONCENTRA- TION OF TREATED SOIL HYDROGEN ION CONCENTRATION OF TREATED SOIL AFTER 38 DAYS AFTER 16 DAYS Dried out Kept moist Dried out Gram mols Gram mols Gram mols per liter Py per liter Py per liter Pg 0.82x10-7 7.09 0.18x10-& 6.75 0.82x10-7 7.09 1.00x10-? 7.00 0.21x10-§ 6.68 0.11x10-* 6.96 0.12x10-* 6.92 0.22x10-* 6.66 0.11x10-* 6.96 1.00x10-7 7.00 0.41x10-* 6.39 0.14x10-° 6.85 0.14x10-° 6.85 0.36x10-* 6.44 0.31x10-° 6.51 0.21x10-* 6.68 0.22x10-§ 6.66 0.18x10-§ 6.75 0.73x10-7 7.14 0.22x10-§ 6.66 0.15x10- 6.82 1.00x10-7 7.00 1.00x10-7 7.00 1.00x10-7 7.00 0.82x10-7 7.09 0.28x10-7 7.95 0.12x10-° 6.92 1.00x10-7 7.00 0.22x10-§ 6.66 0.11x10-* 6.96 114 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 cedures. As will be shown later, there were residual carbonates from the applications of calcium carbonate, as indicated by these two methods. It would seem possible, therefore, that in the hydrogen ion concentra- tion studies there may have been still present part of the applied car- bonate but not enough to come so quickly into solution of distilled water as to indicate alkalinity or neutrality. HYDROGEN ION CONCENTRATION (COLORIMETRIC). Each of the ten soils was examined as to hydrogen ion concentration by L. J. Gillespie, using the colorimetric method. Each sample was reported as being acid by this test. However, it is intended that the results be considered as qualitative only. The results as given by Gillespie are placed in Table 3. TABLE 3. Hydrogen ion exponents determined colorimetrically. Lar 30. ae oe VLD (iene ee aie ei Set Neri Sele een LM has ee bo 1 5.8 SAGAS AR be os tH oA Ios hove ta OE te aes) cary sta aL ers ato 2 5.4 B73) Ln O EG bie Gre Re Sele Oo ae Oe Sern Aiea adore 3 5.6 Co UT | Ee ele oe a ah a ie ce Me SB LG CA ToS 4 4.7 BY Ayers Ap OER ee erotic der okee re moeme oor 5 4.2 LODO Baer i Saar Oe RR ORT SETAE Be EDS 6 5.1 SOO cate oc WP LSE Groce /< Re eee el cee Meee te ere 7 5.9 SOO Leek Ae EMTs fete Spares ieee oh acaeen oaiiiois oh aera ee rte 8 6.4 PABLO aco eres < TeV eK eal a GET eTS RET Se SPSS aOR ee 9 5.3 SPAT era ot de Ai Pe ae ents ain er Geet ideale ns Pee ie ate 10 5.4 * Exponent of 7 indicates neutrality; greater than 7, alkalinity; less than 7, acidity. JONES, HOPKINS AND VEITCH PROCEDURES. In the allotment of work, all three of these methods were assigned to each four laboratories which had voluntarily promised collaborative aid. It is to be regretted, however, that no report has been received from any one of the four laboratories. It is, therefore, impossible to give the indications as to the residual requirements which are to be expected subsequent to treatments as registered by these three methods. FREEZING POINT METHOD. In Table 4 are given the results submitted by G. J. Bouyoucos. The averages upon eleven soils studied by Bouyoucos show 2745 pounds of calcium oxid per 2,000,000 pounds of soil as the initial indications, as against 3139 pounds subsequent to intervals of two weeks and two months. This would seem to indicate either a very considerable analyti- 1920) MACINTIRE: LIME REQUIREMENT OF SOILS 115 cal error or an average increase of over 14 per cent as a result of handling or of handling plus treatment. It would appear that no additions of calcium carbonate were made by Bouyoucos. If such were not the case, the results given would necessarily condemn the method for use in determining the “immediate lime requirement” because of its failure to record any corrective effect or reduction in the lime requirement as a result of applications of appreciable amounts of lime. The associate referee has written Bouyoucos in regard to this point and his reply is here given in toto. TABLE 4. Lime requirement determinations by the freezing point method. POUNDS OF CALCIUM OXID PER 2,000,000 PouNDs OF SOIL L. & P. REFEREE No. NUMBER TYPE After 2 weeks | After 2 months Origi- nal Dry | Moist} Dry | Moist 32347 1 Very fine sandy loam......... 3000 | 3600 | 3600 | 3200 | 2800 32348 2 Sandyelaylonmi,.. 2 =. ..0254- 3000 | 2800 | 2400 | 2700 | 2200 32349 3 Very fine sandy loam......... 3000 | 2800 | 2400 | 2700 | 2200 32350 4 Sandy clay loam. ..........-. 3400 | 3300 | 3000 | 2800 | 2600 32352 5 Sandy humus loam........... 2000 | 2000 | 2200 | 2200 | 2200 32353 6 Very fine sandy humus loam...) 8000 | 7700 | 7700 | 77 7200 32355 if Fine sandy humus loam....... 4000 | 3300 | 3600 | 3300 3300 32361 8 SilGlosmse eM. Fon. el Soe 3000 | 2200 | 2000 | 2200 | 2000 32819 9 Fine sandy loam............. 2000 | 2200 | 2200 | 2200 | 2200 32820 10 Sand yloamis: 20. $52 <5 j202. a - 1200 | 1200 | 1200 | 1200 | 500 32351 LF ot) De er ee Cee es 3700 | 3500 | 3400 | 3300 | 3000 ANETABO Ne EOP e me eae fee ae 3300 | 3145 | 3064 | 3045 | 2745 \ MicuiGaAN AGRICULTURAL COLLEGE Department of Soils East Lansryc, November 10, 1917. Dr. W. H. MacIntire, Tennessee Agricultural Experiment Station, Knoxville, Tenn. Dear Dr. MacIntire: I hasten to reply to your letter of the Sth instant and to inform you that in procur- ing the data which I submitted to you on the lime requirements of soils, as indicated by the freezing point method, I followed exactly the procedure which you outlined in your letter of May 31, 1917. In other words, the soils first received the required amount of precipitated calcium carbonate, as indicated by the freezing point method. The mixing of the soil and precipitated carbonate was done before the soil was moistened. Each soil sample was then moistened and afterward separated into two lots. One portion was kept at the optimum moisture content at which the mixing was done. After periods of 2 weeks and of 2 months, the lime requirement of this soil sample 116 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 was again determined. The other portion of the soil samples was allowed to dry im- mediately and the lime requirement was determined also at the end of 2 weeks and 2 months. In your letter of May 31st, you did not state whether the lime requirement of the moist soil should be determined in the moist condition or should be allowed to dry after it stood the required length of time. For uniformity, I allowed the soil to dry in the air and then determined the lime requirement. It is true that the subsequent lime requirement of the soils was not much affected by the application of the first lime requirement. My further studies of the freezing point method have shown, however, that the soil takes up at once a large amount of lime, and then it continues to take up more lime slowly and gradually for a long time; and the process of air-drying the soil seems to hasten the lime absorption. This continued lime absorption by the soil, which of course you discovered, makes prac- tically all the present lime requirement methods of little use from the practical standpoint. Truog’s contentions, that active and latent acidity are definite and determinable quantities, are wrong, in my opinion. For instance, suppose I deter- mine the active acidity of a soil and apply sufficient lime to correct this active acidity. Then, I send Truog a sample of this soil and ask him to ascertain the kind and amount of acidity of this soil. If he does not know that I have already corrected the active acidity, would he not call the acidity he finds active? Whereas, if he knew that I have corrected this already, he would call it latent. It is very probable that before the soils would refuse to take up any more lime or make a very decided decrease in the subsequent lime requirement, four or five times the original amount of lime would have to be added, at least in some of the soils. It seems that before a soil refuses to take up any more lime, it must be completely sat- isfied with the lime and that the lime phase should begin to remain in the soil solution. When a soil is brought into contact with an excess amount of lime, it takes up almost instantaneously a large amount of lime and the remainder very slowly. Thus a soil may take up 10,000 pounds of calcium oxid per acre in 2 or 3 minutes and an addi- tional amount of 10,000 pounds in 10 or 12 days. The additional absorption is so slow that it leads one to conclude that the final equilibrium is attained instantaneously. The final equilibrium of absorption, however, is greatly hastened by repeatedly air- drying the soil after it is treated with an excess of lime. It may be of interest and probably of some use to you in preparing your report to know that in conducting an investigation to determine the rate of reaction between soils and salts, acids and bases, and the behavior of equilibrium, I found that in the case of the bases, which included calcium hydroxid, sodium hydroxid, potassium hydroxid and ammonium hydroxid, the reaction between the soils and the last three bases was almost instantaneous and the equilibrium remained constant for a long time, in many cases, 100 days. In the case of the calcium hydroxid, however, the equilibrium continued to change (or the concentration continued to decrease) slowly and gradually for a long time. According to these results, it would seem that the soils do not continue to take up sodium hydroxid, potassium hydroxid and ammonium hydroxid, but they do continue to take up calcium hydroxid. Hoping that I have made the matter clear, I am, Sincerely yours, Gro. Bouyoucos. TACKE AND MACINTIRE METHODS. Four methods have been advanced for the determination of lime requirement by the use of calcium carbonate. The Tacke procedure and 1920) MACINTIRE: LIME REQUIREMENT OF SOILS ate) TABLE 5. Lime requirement by the Tacke method upon untreated and treated soils. CARBON DIOXID EVOLVED SUBSEQUENT TO TREATMENT CARBON DIOXID EVOLVED Dried Moist 2 weeks Moist 4 weeks SOIL FROM ORIGINAL cc. N20 Cc. N /20} Per cent | Ce. N /20| Per ae Cc. N /20} Per Fete NORMA Baan, orinnal mality Signal mality original 1. Very fine sandy loam) 15.50 5.35 | 34.5 6.60 | 42.6 6.40 | 41.3 2. Sandy clay loam....| 16.05 9.25 | 57.6 6.60 | 41.1 5:10) ||, S505 3. Very fine sandy loam) 13.20 7.05 | 53.4 5.45 | 41.3 5.45 | 41.3 4. Sandy clay loam....| 27.90 9.10 | 32.6 7.00 | 25.1 5.85-| 21.0 5. Sandy humus loam .| 48.80 17.60 | 36.1 16.20 | 33.2 17.05 | 34.9 6. Very fine sandy hu- mus loam........ 36.40 13.05 | 35.8 13.60 | 37.3 12.60 | 34.6 7. Fine sandy humus loanitPs see se 27.45 11.70 | 42.6 10.40 | 37.9 11.00 | 40.1 Se euleOAMN -.= 25575 5,05 2 10.50 6.20 | 59.0 5.00 | 47.6 4.65 | 44.3 9. Fine sandy loam....| 13.80 4.70 | 34.1 5.25 | 38.0 4.20 | 30.4 10. Sandy loam........ |} 16.15 9.00 | 55.7 4.70 | 29.1 4.20 26.0 } AVOLA gE so). 2s: 22.58 9.30 | 44.1 8.08 | 37.3 | 7.71 | 34.9 | | | the Siichting modification of this procedure involve the reaction which transpires between a distilled water solution of calcium carbonate and an acid soil. The modification is based upon the assumption that the continued evolution of carbon dioxid over long periods of contact be- tween soil and carbonate is due to the action of calcium carbonate upon soil organic matter and seeks to eliminate this objection. In studies upon the Tacke method, the associate referee has found that this con- tinued evolution of carbon dioxid is rather a function of the speed of reaction, which is depressed because of the limited solubility of calcium carbonate. As a matter of fact, clay subsoils almost devoid of organic matter demonstrate this continued evolution in a more marked degree than do many surface soils relatively high in their organic matter con- tent. The Siichting modification is based upon the erroneous assump- tion that a strong hydrochloric acid solution is less active than a weak calcium carbonate solution upon soil organic matter and that all of the carbon dioxid evolved from the action of acid on soil, plus residual carbonate from that applied, is to be accredited to the carbonate alone. The Tacke method was deemed to be less free of objection and simpler than the Siichting technique and it was accordingly used as more repre- sentative of this type or procedure. The other two methods which employ a solution of calcium carbonate are that of Hutchinson and MacLennan which directs the treatment of a soil with a cold bicarbonate 118 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 TABLE 6. Data showing the speed of the reaction involving the evolution of carbon dioxid in the Tacke procedure. CARBON DIOXID EVOLVED ~ 5 During third 3 During abst Domine second hours after stand- Total SOIL ing overnight Cc. N /20} Per cent | Ce. N /20} Per cent | Cc. N /20| Per cent | Ce. N /20] Per cent nor- calcium nor- calcium nor- calcium nor- calcium mality |carbonate| mality |carbonate| mality |carbonate| mality |carbonate 1. Very fine sandy loam..| 15.5 0.194 7.0 0.088 8.3 0.104 | 30.8 0.386 2. Sandy clay loami-se eee 16.05 | 0.201 7.0 0.088 9.65 | 0.121 | 32.7 0.410 3. Very fine sandy loam. .| 13.2 0.165 3.85 | 0.048 6.35 | 0.079 | 23.4 0.292 4. Sandy clay IDET Sebe 27.9 0.349 8.4 0.105 7.7 0.096 | 44.0 0.550 5 Mpa: ae tel, 48.8 0.610 | 11.1 0.139 | 10.0 0.125 | 69.9 0.874 6. Very fine sandy humus loam........| 36.4 0.455 | 11.05 | 0.138 9.5 0.119 | 56.95 | 0.712 7. Fine sandy humus loam.| 27.45 | 0.343 | 14.2 0.178 | 15.15 | 0.189 | 56.8 0.710 8. Silt loam....| 10.5 0.131 3.75 | 0.047 6.45 | 0.081 | 20.7 0.259 9. Fine sandy Noam nck: c15 13.8 0.173 4.65 | 0.058 7.45 | 0.093 | 25.9 0.324 10. Sandy loam .| 16.15 | 0.202 4.30 | 0.054 6.8 0.085 | 27.25 | 0.341 Average..... 22.58 | 0.282 7.53 | 0.094 8.74 | 0.109 | 38.84 | 0.486 solution and total pressure of carbon dioxid, instead of partial; and that of the writer which directs the evaporation of soil and calcium bicarbonate, followed by the estimation of residual calcium carbonate by means of acidulation and agitation under reduced pressure at room temperature. A study of the Hutchinson and MacLennan method by the associate referee and by F. W. Bouson of the associate referee’s laboratory has shown that the carbonated water effects either a forcing back of the reaction responsible for the decomposition of the carbonate or else a hydrolysis of the native silicates, thus, in a number of in- stances, yielding a solution of alkalinity greater to titration than that of the original bicarbonate solution, and this upon soils shown by the the Veitch, Tacke and MacIntire procedures to be distinctly acid. In view of the foregoing facts, the Tacke and Tennessee Agricultural Ex- periment Station methods were used as being less characterized by glaring faults. The results secured upon the Tacke method are given in Table 5. 1920) MACINTIRE: LIME REQUIREMENT OF SOILS 119 TABLE 7. Lime requirement by the MacIntire method upon untreated and treated soils. CALCIUM CARBONATE DECOMPOSED BY SOIL SUBSEQUEN1 CALCIUM TO TREATMENT CARBONATE DECOMPOSED BY — ORIGINAL SOIL Dried Moist 2 weeks Moist 4 weeks Cc. N /20) Per cent | Ce. N /20) Per cent | Cc. N /20) Per cent | Cc. N /20) Per cent nor- | calcium nor- calcium nor- calcium nor- calcium mality carbonate} mality jcarbonate| mality |carbonate| mality |carbonate I . Very fine sandy loam..| 17.70 | 0.221 8.60 | 0.107 | 6.40 | 0.080 3.20 | 0.040 . Sandy clay | loam... /5- .2 24.80 | 0.310 7.30 | 0.091 5.50 | 0.069 3.10 | 0.038 sandy loam..! 20.30 | 0.253 5.40 | 0.068 | 6.40 | 0.080 1.50 | 0.019 . Sandy clay } Moa hee :s 2 ee 33.10 | 0.414 | 18.10 | 0.226 | 14.50 | 0.181 5.50 | 0.069 or Ne oy < io") 2 =o 5 o loam ier. 222" 81.30 1.016 | 11.70 | 0.146 5.50 | 0.069 7.90 | 0.099 6. Very fine | sandy humus loam be) he) 56.60 | 0.708 | 16.80 | 0.210 | 12.40 | 0.155 | 17.70 | 0.221 humus loam . 44.80 | 0.560 | 17.70 | 0.221 | 13.20 | 0.165 | 11.50 | 0.144 8: Silt loam...) 25.00 | 0.313 | 14.20 | 0.178 | 10.40 | 0.130 9.40 | 0.118 9. Fine sandy leamre ee a 23.00 | 0.288 2.90 | 0.036 2.60 | 0.033 10. Sandy loam .| 22.80 | 0.285 | .... ee 7.70 | 0.096 Average..... 34.94 | 0.437 | 11.41 | 0.143 8.46 | 0.106 7.48 | 0.094 The indications obtained by this method were secured by the use of the following technique: Twenty grams of air-dried soil and 5 grams of C. P. precipitated carbonate of lime, previously treated with carbonated water, were placed in 300 cc. Erlenmeyer flasks and aspirated for 15 minutes under 5 inches reduced pressure. Distilled water, carbon dioxid-free, was then added and the agitation and aspiration continued for a 3-hour period. In order to obtain additional data as to the completion of the carbon dioxid evolution and as to the speed of reaction, the agitation and aspiration were continued for a second period of 3 hours and again for 3 hours after being allowed to stand overnight. These results are given in terms of N/20 acid, in order to convey some idea of what dependence may be placed in differences of the magnitude obtained, and also in terms of percentages of the initial indication, in the cases of the repetitions after treatments. The data of Table 5 bring out the following points: Applications of the amounts indicated initially do not prevent further lime requirement indications after spontaneous drying and after inter- 120 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 TABLE Estimation of residual caleium carbonate from amounts applied AFTER APPLICATION OF AMOUNTS INDICATED BY THE TACKE PROCEDURE 10-GRAM CHARGES Increase over blank | Increase over blank | Increase over blank OF COMPOSITE Blank after spontaneous after remaining after remaining SOIL SAMPLES drying wet 2 weeks wet 1 month A* By A* Bt A* By A* Bt 1, 2,3 and 4 4.15 0.104 0.85 0.021 1.25 0.031 1.30 0.033 5, 6, 7 and 8 3.05 0.076 1.25 0.031 1.55 0.039 2.40 0.060 Average......| 3.60 0.090 1.05 0.026 1.40 0.035 1.85 0.047 * Results expressed in ec. N /20 normality. vals of two weeks and one month under moist conditions. That this is in part due to incomplete decomposition of the applied carbonate is indicated by the analyses for combined carbon dioxid, Table 8, upon two composite samples, each composite being made from equal amounts of each of four soils. The blanks on the composites of the original soils do not represent absolute carbonate determinations upon the acid soils, but they include the atmosphere of the apparatus, as well as the result of the slight action of the liberating acid upon soil organic matter. It is of interest to note that in the case of both of the composites where applications were made according to the indications of the Tacke method and also those obtained by the Tennessee Agricultural Ex- periment Station method the residual carbonate appeared to be higher where moist conditions were maintained than where spontaneous dry- ing was effected. Such a result would not be expected. It would seem that this finding must be attributed either to consistent analytical error, or to the possible retention of the carbon dioxid from the carbon- ate decomposition within the closed containing bottle, thus either retarding the absorption of calcium carbonate or effecting the reversal of the reaction by hydrolysis of calcareous soil components in the manner previously mentioned as characteristic of the Hutchinson and Mac- Lennan method. The average initial lime requirement of the ten soils studied was represented by a carbon dioxid evolution equivalent to 22.58 ec. of N/20 acid for the three-hour period of contact while the subsequent lime requirements after treatment, as indicated by the initial determination, were 44.1, 37.32, and 34.94 per cent of the originals, for the spontaneous drying, two weeks and four weeks under moist condition, respectively. However, the average requirement indication during the second three- hour period was 33 per cent greater than that of the first three-hour 1920] 8. MACINTIRE: LIME REQUIREMENT OF SOILS according to indications of the Tacke and MacIntire procedures. 121 AFTER APPLICATION OF AMOUNTS INDICATED BY THE MacINTIRE PROCEDURE 10-GRAM CHARGES Increase over blank | Increase over blank | Increase over blank OF COMPOSITE Blank after spontaneous after remaining after remaining SOIL SAMPLES drying wet 2 weeks wet 1 month A* By A* Bt A* By A* Bt 1, 2,3 and 4....} 4.15 0.104 0.05 0.001 3.85 0.096 3.55 0.089 5,6, 7 and 8....| 3.05 0.076 4.25 0.106 5.65 0.141 4.05 0.101 Average...... 3.60 0.090 2.15 0.054 4.75 0.119 3.80 0.095 T Per cent calcium carbonate. period, while this indication plus the third three-hour period results gave an indication equivalent to 72 per cent of the initial indication. These data upon the same soils, which were studied by the lime water titration and hydrogen ion concentration method, show that the longer period of contact allowed in the Tacke procedure would have indicated amounts of calcium carbonate which would probably have more than attained the condition of reaction found in the studies carried out by Sharp and Hoagland. The determinations by the Tennessee Agricultural Experiment Sta- tion method were analogous to those obtained by the Tacke procedure, . although the former method gave a lime requirement 50 per cent higher than that recorded by the Tacke procedure during a three-hour period. The average of the subsequent lime requirements showed 32. 24 and 21 per cent, respectively, of the average initial indication for the spon- taneous drying and moist periods of two weeks and one month. This residual lime requirement does not necessarily mean, however, that insufficient calcium carbonate was applied, but it is in part accounted for by the fact that the reaction between the soil and the carbonate had not been complete, as evidenced by the appearance of minute particles of carbonate and by the increase in the amounts of carbonate carbon dioxid. This method differs from the Tacke procedure in that the residual carbonate enters quantitatively into the repetition of the method upon the carbonate treated soil and decreases from actual to apparent the amount of carbonate absorbed in the subsequent trials. Since the foregoing was written, the associate referee has received additional data from L. J. Gillespie upon soils, the history of which was unkrown to him. Four samples of soil which had been treated with the amounts of calcium carbonate indicated by the Tacke procedure and by the MacIntire procedure, and then permitted to remain wet two 122 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 weeks, and four spontaneous dryings of the latter method only, were examined in order to ascertain their subsequent or residual hydrogen ion concentration. The results are incorporated in the following table: TABLE 9. Relation of the amounts of calcium carbonate to the attainment of neutrality, as determined by hydrogen ton concentration. HYDROGEN ION CONCENTRATION REFEREE NUMBER Moist Dry Originally - Tacke MaclIntire MaclIntire Deo eave tetas Sas kanes Le Malis oats i ceoteabena walters a's tase 5.8* Zell 7.4 7.3 DS TS Keys Cr EES Te eae ree 5.4 tz 7.4 Ue 4g oS. us VE mhoiuc Sones Oe eeise 41s .sehie 4.7 7.0 7.3 2 Sides coe segura hie letereiersy ster eiate sees iauete Slot 6.4 7.3 7.4 Ue? * Exponent of 7 expresses neutrality; greater than 7, alkalinity; less than 7, acidity. The foregoing data demonstrate that the treatments indicated by both the Tacke and MaclIntire procedures will effect neutrality or rather slight alkalinity as measured by hydrogen ion concentrations. The alkalinities recorded by hydrogen ion concentration determinations are practically the same for both methods. However, the applied treat- ments indicated by the MacIntire procedure were about 50 per cent greater than those of the Tacke procedure. It is of interest to note that a comparison of the hydroxyl ion concen- trations of the spontaneous drying treatments, with those of the treat- ments which remained moist, exhibits a slight but constantly greater alkalinity in the case of the moist treatments. This is in accord with the finding by Bouyoucos of lesser residual lime requirements in the case of the moist contacts as compared to spontaneous drying. The hydroxyl ion concentrations above referred to are also in accord with the data of Tables 5 and 9. The data of Table 5 show a higher subse- quent lime requirement after maintenance of moist condition, as com- pared with spontaneous drying; while the data of Table 9 indicate a greater residual calcium carbonate content for the moist maintenance as compared with spontaneous drying after applications as registered by both the Tacke and the MacIntire methods. It has been pointed out by a number of those interested in the lime problem, in its relation to soils, that the term “Lime Requirement” is somewhat vague and indefinite, and that it suggests the query “Lime requirement for what?” It is certainly true that it does not definitely indicate whether a chemical equilibrium is thus designated or reference 1920] MACINTIRE: LIME REQUIREMENT OF SOILS 123 is made to plant response. It is positively demonstrated by the fore- going, and also by other studies, that a soil exhibiting alkaline reaction by one test may still effect considerable decomposition of calcium carbonate, when soil and carbonate are permitted contact under con- trolled conditions. It is, therefore, believed that the term “Lime Absorp- tion Coefficient” is more definite and to be preferred. As previously stated, the Hopkins, Jones and Veitch methods were assigned to several laboratories but no report was received upon these procedures. If it were not for its tediousness, the Veitch method would be very much more acceptable. Nevertheless, it is based upon a prin- ciple which precludes a large variation in the active mass of the applied alkali. The Hopkins method was formerly included in the official methods of this association. It has been shown, however, that it is not permissible to assume that molar equivalent amounts of the various basic ions are absorbed when presented to soils in the form of neutral salt solutions. For this reason, the method is not now in general use, in so far as the writer has been able to learn. There is a method, how- ever, which offers very attractive features. This is known as the Jones method. It presents to the soil a lime salt, and it has the advantage of being very rapid and susceptible of close duplication and requires no setting up of apparatus. Irrespective of the merits of the other methods, it is the belief of the associate referee that the Jones method offers the greatest possibilities for obtaining the coefficient of lime absorption. RECOMMENDATIONS. It is recommended— (1) That the work of the ensuing year be directed along lines which will fully develop the optimum conditions for carrying out the Jones method. 3 (2) That future work on the problem be done by a referee to be designated as referee on the problem of “Lime Absorption Coefficient”’. Messrs. B. L. Hartwell, F. R. Pember and L. P. Howard (Agricultural Experiment Station, Kingston, R. I.) presented a paper on “Lime Re- quirements as Determined by the Plant and by the Chemist””!. 1 Soil Science, 1919, 7: 279. 124 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 THE DETERMINATION OF CALCIUM IN THE PRESENCE OF PHOSPHATES". By J. F. Breazeae (Shula Vista, Calif.), Referee on Inorganic Plant Constituents. It is well known that, when dilute oxalic acid is added to solid calcium phosphate [Ca; (PO.)2], the calcium phosphate is converted into calcium oxalate, not partially but, practically speaking, wholly. The fact that calcium oxalate is more insoluble than calcium phosphate may be shown readily by precipitating the calcium from a saturated solution of calcium phosphate by means of oxalic acid. The phosphates of mag- nesium, iron and aluminium, on the other hand, are readily soluble in oxalic acid. DETERMINATION OF CALCIUM. Method I. (When little or no manganese is present.) Start with a dilute hydrochloric acid solution of an ash, containing calcium, mag- nesium, an excess of phosphates and some iron, take an aliquot, heat to boiling, add a few drops of methyl orange as an indicator, and make slightly alkaline with ammonia. This will precipitate the phosphates of calcium, magnesium and iron. Add a saturated solution of oxalic acid until the solution is slightly acid. If too much ammonia has been added, boil off the excess before adding the oxalic acid so as to avoid having so much ammonium oxalate in the solution. The oxalic acid will dissolve the phosphates of iron and magnesium and convert the calcium phosphate into calcium oxalate. Again make the solution slightly alkaline with ammonia, and then slightly acid with oxalic acid. While this procedure is not always necessary, the precipitation seems to be better, especially when the solution contains small amounts of calcium oxid and relatively large amounts of ammonium and sodium salts. The final filtration must be done in an oxalic acid solution. Keep the solution hot and allow it to stand until the calcium oxalate settles in its characteristic way. This requires 10-60 minutes. The calcium oxalate, when precipitated in acid solution, is more crystalline and filters more readily than when precipitated in the presence of ammonia. Filter, wash with hot water, ignite and weigh as calcium oxid, or dissolve the precipitate in sulphuric acid solution and titrate with standard potassium permanganate. In the calcium determination, as ordinarily conducted in the presence of magnesium (precipitating with ammonia and ammonium oxalate), when the calcium oxalate precipitate is large, a little magnesium is often occluded with the calcium oxalate?. Except when there is a large amount of lime this is not a serious error, but it can be overcome easily by dissolving the calcium oxalate in dilute hydrochloric acid and reprecipitating with ammonia and ammonium oxalate. In the method above described, when there is a large amount of lime, and it is desired 1 Presented by G. H. Baston. 2 Proc. Am. Acad. Arts Sci., 1901, 36: 377; J. Am. Chem. Soc., 1909, 31: 917. 1920| BREAZEALE: CALCIUM IN THE PRESENCE OF PHOSPHATES 125 to ignite the calcium oxalate precipitate and to weigh the lime as cal- cium oxid, it is advisable to redissolve the calcium oxalate and again precipitate with ammonia and oxalic acid. However, if the magnesium is not desired in the filtrate and the calcium is to be titrated with potas- sium permanganate, a second precipitation is not necessary as the magnesium is occluded as phosphate and not as oxalate. Method II. (When manganese is present.) The above directions apply to the determination of calcium in the ash of plants and similar materials when little or no manganese is present. In the presence of an appreciable amount of manganese, a slight modi- fication is necessary, as manganese oxalate will precipitate in the pres- ence of oxalic acid in much the same way as calcium oxalate. Precipitate an aliquot of the original solution with oxalic acid, as before described, filter and wash a few times to remove all of the phosphates. Dissolve the precipitate, containing calcium and manganese oxalates, in hydrochloric acid, using 10 ce. or more of acid in order to have plenty of ammonium chlorid in the solution when reprecipita- tion takes place. Make the solution alkaline with ammonia and add a little ammonium oxalate. The calcium oxalate will be reprecipitated, while the manganese will remain in solution. Filter, wash, dissolve in dilute sulphuric acid and titrate with standard potassium permanganate. A characteristic property of manganese is that it is pre- cipitated as the white hydroxid [Mn(OH).], which soon darkens upon exposure to the air and forms manganese trioxid. Ammonia behaves similarly if no ammonium salts are present. In the presence of ammonium chlorid, however, the precipitation is held back in much the same way as that of magnesium. Manganous hydroxid is dissolved by ammonium chlorid in direct proportion to the concentration of ammonium ions in solution. Therefore, have plenty of ammonium chlorid present when the precipitation is made and filter as soon as possible. Excellent results have been obtained with small amounts of lime in the presence of 0.5 per cent of manganese sulphate. If manganous hydroxid begins to form in the solution before the filtration, it can be detected readily by its dark color. In such a case, dissolve the precipitate in hydrochloric acid and again make alkaline with ammonia. In this way, more ammonium chlorid will be brought into the solution and the precipitation will be held back. With ordinary care, in a precipitation with oxalic acid alone, such as has been before described, there is little danger of any calcium being held in solution by the oxalic acid. SOLUBILITY OF CALCIUM OXALATE IN OXALIC ACID AT ROOM TEMPERATURES. A test solution, made slightly acid with hydrochloric acid, was prepared, containing 0.1000 per cent of calcium, 0.0497 per cent of magnesium and 0.2900 per cent of phosphoric acid. Aliquots con- taining 0.0100 gram each of calcium were withdrawn, neutralized with ammonia, solid oxalic acid added in the cold, as indicated in Table 1, 126 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 and the solutions made up to 50 cc. The solutions were allowed to stand overnight at room temperature, filtered, washed with cold water and the calcium oxalate titrated with potassium permanganate. TABLE 1. Solubility of caletum ozalate in cold solutions of oxalic acid. CALCIUM RECOVERED SSE (0.0100 GRAM ADDED) per cent gram 1.0 0.0100 2.5 0.0100 5.0 0.0098 10.0 0.0099 These determinations were repeated several times with results almost as good as those given. Evidently, there is little or no solubility of the calcium oxalate in the oxalic acid under these conditions. SOLUBILITY OF CALCIUM OXALATE IN HOT SOLUTIONS OF OXALIC ACID. Aliquots of the test solution, before described, were withdrawn, brought to the boiling point, neutralized with ammonia, and solid oxalic acid added. The solutions were kept boiling hot for 1 hour, filtered, washed with hot water and the calcium oxalate titrated with potassium permanganate. TABLE 2. Solubility of calcium oralate in hot solutions of oxalic acid. f D. Vv OxALIC ACID | (00100 GRAM ADDED) per cent gram 0.1 0.0098 0.5 0.0100 1.0 0.0097 2.0 0.0098 3.0 0.0096 5.0 0.0090 10.0 0.0087 20.0 0.0081 30.0 0.0078 These determinations were also repeated several times with this and lower concentrations of calcium. As might be expected, the solubility of the calcium oxalate is about the same in concentrations of 50 parts per million of calcium as it is in 100 parts per million, approaching a solubility of about 20 parts per million at a concentration of 30 per cent of oxalic acid. 1920| BREAZEALE: CALCIUM IN THE PRESENCE OF PHOSPHATES 127 SOLUBILITY OF CALCIUM OXALATE IN SOLUTIONS OF AMMONIUM SALTS IN THE PRESENCE OF OXALIC ACID. As the precipitation of calcium usually takes place in the presence of more or less ammonium salts, the solubility of calcium oxalate in ammonium nitrate, ammonium chlorid and ammonium sulphate was determined. The aliquots, containing 0.0100 per cent of calcium with increasing amounts of ammonium salts, were brought to the boiling point, made alkaline with ammonia, and then made slightly acid with oxalic acid. They were kept hot for 1 hour, then filtered and titrated. TABLE 3. Solubility of calcium oxalate in solutions of ammonium nitrate in the presence of oxalic acid. AMMONIUM NITRATE (0.0100 GaaehobeD) per cent gram 1.0 0.0099 5.0 0.0095 10.0 0.0100 20.0 0.0098 50.0 0.0097 TABLE 4. Solubility of calcium ozalate in solutions of ammonium chlorid in the presence of oxalic acid. AMMONIUM CHLORID | CALCIUM RECOVERED (0.0100 GRAM ADDED) per cent gram 1.0 0.0098 5.0 0.0099 10.0 0.0100 20.0 0.0100 TABLE 5. Solubility of calcium oxalate in solutions of ammonium sulphale in the presence of oxalic acid. AMMONIUM CALCIUM RECOVERED SULPHATE (0.0100 GRAM ADDED) per cent gram 1.0 0.0099 5.0 0.0097 10.0 0.0096 20.0 0.0094 128 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 Repeated experiments show that there is little or no solubility of the calcium oxalate in either ammonium nitrate or ammonium chlorid at any concentration encountered in ordinary work. With ammonium sulphate, there seems to be a slight solubility at high concentrations. In dissolving the original ash it is advisable, therefore, to use either hydrochloric or nitric acid in preference to sulphuric. Another point which should be borne in mind in precipitating calcium oxalate in the presence of large amounts of either ammonium or sodium salts, is that the presence of such salts has a decided tendency to retard the precipitation of calcium. This is particularly true of ammonium sulphate. In such cases, it is advisable first to make the solution slightly alkaline with ammonia, then slightly acid with oxalic acid. If the calcium oxalate is not precipitated on stirring, the solution should be made slightly alkaline again with ammonia and then reacidified with oxalic acid. This procedure will immediately precipitate quantities of calcium oxalate that would otherwise perhaps not be precipitated at all, or would require several hours for complete precipitation. This is usually necessary only in the presence of large amounts of ammonium or sodium salts. SOLUBILITY OF CALCIUM OXALATE IN SOLUTIONS OF SODIUM SALTS IN THE PRESENCE OF OXALIC ACID. The effect of sodium salts upon the precipitation of calcium oxalate was determined in the same way as has been described for the ammonium salts. The procedure that would be followed in any ordinary calcium determination was followed in each case. The results were not intended as definite solubility measurements but more as a measurement of the probable error one might expect in every day work. TABLE 6. Solubility of calcium oralate in solutions of sodium nitrate in the presence of oxalic acid. CALCIUM RECOVERED SOOT ies (0.0100 GRAM ADDED) per cent gram 1.0 0.0097 5.0 0.0100 10.0 0.0100 20.0 0.0099 40.0 0.0099 1920| | BREAZEALE: CALCIUM IN THE PRESENCE OF PHOSPHATES 129 TABLE 7. Solubility of calcium oxalate in solutions of sodium chlorid in the presence of oxalic acid. SODIUM CHLORID NGtaTOUTaEsaae ODES) per cent gram 1.0 0.0100 5.0 0.0099 10.0 0.0101 20.0 0.0098 30.0 0.0098 TABLE 8. Solubility of calcium oralate in solutions of sodium sulphate in the presence of oxalic acid. CALCIUM RECOVERED SOULE E SS (0.0100 GRAM ADDED) per cent gram 1.0 0.0099 5.0 0.0100 10.0 0.0100 20.0 0.0099 While not indicated in Table 8, there is often a slight solubility of calcium oxalate in the highest concentrations of sodium sulphate. These tables, however, show that the solubility of calcium oxalate in sodium salt solutions is negligible under the conditions of ordinary work. SOLUBILITY OF CALCIUM OXALATE IN SOLUTIONS OF PURE SODIUM SALTS. Contrary to what might be expected from the results just given, the solubility of calcium oxalate in solutions of sodium salts, when no oxalic acid or ammonium oxalate is present, is considerable. Pure calcium oxalate was prepared and an excess of the salt added to 100 ce. portions of neutral solutions of sodium nitrate and sodium sulphate. The solutions were shaken at room temperature until equilibrium was established. The excess of calcium oxalate was then filtered off and the amount that had gone into solution was determined by acidifying the filtrate with sulphuric acid and titrating with permanganate. With the sodium chlorid solutions, however, this procedure could not be followed, as the higher concentrations of the salt affected the permanganate titration. Therefore, definite amounts of the calcium oxalate were added to the sodium chlorid solutions and these brought to equilibrium. The calcium 130 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 oxalate remaining undissolved was then filtered off, washed, dissolved in dilute sulphuric acid and titrated. These solubility determinations are shown in Tables 9, 10 and 11. TABLE 9. Solubility of calcium oralate in solutions of pure sodium nitrate al room temperature. I CALCIUM OXALATE SOD EOSIN DISSOLVED IN 100 cc. per cent gram 0.0 trace 1.0 0.0024 5.0 0.0048 0.0 0.0054 0.0 0.0068 0.0 0.0 0.0072 0.0066 Taste 10. Solubility of calcium oxalate in solutions of pure sodium chlorid at room lemperature. CALCIUM OXALATE m UDR NGE OED DISSOLVED IN 100 cc. per cent gram 0.0 trace 1.0 0.0019 5.0 0.0048 10.0 0.0058 20.0 0.0067 30.0 0.0058 TABLE 11. Solubility of calcium oralate in solutions of pure sodium sulphate al room temperature. CALCIUM OXALATE SODIUM SULPHATE | pissoLvED IN 100 cc. per cent gram 0.0 trace 1.0 0.0029 5.0 0.0058 10.0 0.0106 20.0 0.0154 The calcium oxalate was found to be equally as soluble in slightly ammoniacal solutions of sodium salts as in the neutral solutions. 1920| BREAZEALE: CALCIUM IN THE PRESENCE OF PHOSPHATES 131 SOLUBILITY OF CALCIUM OXALATE IN SOLUTIONS OF PURE SODIUM SALTS AT THE BOILING POINT OF THE SOLUTION. Increasing concentrations of sodium nitrate, sodium chlorid and sodium sulphate were prepared, as shown in Tables 12, 13 and 14, and made slightly alkaline with ammonia. The reason for adding the ammonia was that the salts were often found to be slightly acid. These solutions were then brought to the boiling point and 0.0800 gram of pure, freshly precipitated calcium oxalate added to each. The solutions were kept boiling for 1 hour, filtered, the residue of calcium oxalate washed, dissolved and titrated. The difference between the amount of calcium oxalate remaining undissolved in the sodium salt solutions and that in the water represents the solubility of calcium oxalate. TABLE 12. Solubility of calcium ozalate in boiling solutions of sodium nitrate. = = CALCIUM OXALATE PRECIPITATED SODIUM NITRATE 2 oe 100 che enom DL reare, wie 0. PER per cent 3 gram gram 0.0 0.0000 0.0000 1.0 0.0019 0.0019 5.0 | 0.0054 0.0070 10.0 | 0.0067 0.0083 20.0 0.0093 0.0105 40.0 0.0125 0.0128 60.0 0.0125 0.0128 Taste 13. Solubility of calcium oxalate in boiling solutions of sodium chlorid. CALCIUM OXALATE REPRECIPITATED FROM FILTRATE WITH 0.5 PER CENT OF OXALIC ACID CALCIUM OXALATE SLUTS DISSOLVED IN 100 cc. per cent gram gram 0.0 0.0000 0.0000 1.0 0.0054 0.0045 5.0 0.0086 0.0067 10.0 0.0093 0.0086 20.0 0.0099 0.0093 30.0 0.0099 0.0077 | The filtrates from these precipitates, with the calcium oxalate held in solution by the sodium salts, were then evaporated to a volume of 100 ce. and 0.5 per cent of oxalic acid added to each. In the higher concentrations of the sodium salts, the method of precipitation referred to before was adopted; that is, the solutions were first acidified slightly 132 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 with oxalic acid, made slightly alkaline with ammonia, then distinctly acid with oxalic acid. The amount of calcium oxalate reprecipitated in the filtrates is also shown in the tables. TABLE 14. Solubility of calcium oxalate in boiling solutions of sodium sulphate. CALCIUM OXALATE REPRECIPITATED FROM FILTRATE WITH 0.5 PER CENT OF OXALIC ACID CALCIUM OXALATE = 7 SADA SEES DISSOLVE? IN 100 cc. per cent gram gram 0.0 0.0000 0.0000 1.0 0.0048 0.0038 5.0 0.0150 0.0147 10.0 0.0237 0.0221 20.0 0.0355 0.0320 By reference to the above tables it will be seen that calcium oxalate is especially soluble in pure sodium salts and that this solubility is almost completely overcome by the addition of a common ion, oxalic acid. TESTS OF THE OXALIC ACID METHOD. A stock solution of pure salts was prepared, containing 0.1002 per cent of calcium, 0.1688 per cent of magnesium and 0.5000 per cent of phosphoric acid with sodium and potassium salts and iron added as impurities. This was an imitation of a plant ash. Aliquots of this stock solution were drawn off by C. A. Jensen, Riverside, Calif., and given to the writer in two sets, in amounts unknown to him, for test deter- minations. The first set contained relatively large amounts, while the second had very small amounts of calcium. These two sets were run TABLE 15. Test analyses of solutions containing relatively large amounts of calcium. CALCIUM ADDED Cho eee By gram gram 0.0368 0.0366 0.0109 0.0103 0.0011 0.0010 0.0022 0.0020 0.0478 0.0487 0.0043 0.0040 0.0327 0.0339 0.0010 0.0008 0.0120 0.0115 1920| BREAZEALE: CALCIUM IN THE PRESENCE OF PHOSPHATES 133 when the work upon the method was first begun, and before very much technique had been developed. They represent the degree of accuracy that might be expected from any analyst. The results are given in Tables 15 and 16, without any duplication and without any determina- tion being left out. Taste 16. Test analyses of solutions containing relatively small amounts of calcium. carcrom appep | CAECreM FOUND By gram gram 0.0004 0.0003 0.0005 0.0005 0.0007 0.0006 0.0004 0.0003 0.0010 0.0008 0.0005 0.0003 0.0007 0.0005 0.0007 0.0007 By keeping the solution down to a small volume, an accurate deter- mination of calcium can be made, in amounts as Jow as 0.0005 gram, in the presence of an excess of phosphates. The same degree of accuracy is noted in relatively large amounts. The accuracy in the lower con- centrations makes the method well adapted to the analysis of the ash of such material as wheat seedlings, when the calcium in 100 seeds or 100 plants, which is a convenient quantity to use, runs about 0.0050 gram. It often happens that an analyst can get good results with his own method, when other analysts find it unsatisfactory. To test this point, samples of the imitation ash solution, described above, were sent to TasLeE 17. Comparative analyses by cooperating chemists. ANALYST CALCIUM ADDED | CALCIUM FOUND gram gram B. F. Robertson, Clemson Agricultural College, Clemson CTICER ST GHG RE ee ete a ar eer eae etree Bee 0.0501 0.0498 C. S. Lykes, Clemson Agricultural College, Clemson ULETE IGE GE eaniere: cont tt Se ge See ea 0.0501 0.0497 ae el: Grondall, Riverside, Calif....-...5........--2--- 0.0501 0.0498 Wear Kelley. Riverside, Califa... 65 cei. oc nie eicacce ee = 0.0501 0.05075 134 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 the analysts mentioned in Table 17, with the request that 50 cc. aliquots be taken and analyzed for calcium by the oxalic acid method. The results are given in Table 17. It is not claimed that this method is advisable in all cases of plant analysis, but, with the ash of cereals and seedlings, especially when calcium alone is desired, it is rapid and accurate. After the calcium has been removed by the oxalic acid, iron, alumina and magnesium may be determined in the filtrate. Very few ashes con- tain enough iron or aluminium to amount to anything in the gravimetric determination, so ordinarily they may be left out of consideration. The procedure is as follows: Neutralize the excess of oxalic acid with ammonia, evaporate the filtrate to dryness, drive off all ammonium salts, take up with a little hydrochloric acid and precipitate the magnesium as phosphate in the regular way. In case iron or aluminium is present, evaporate, drive off the ammonium salts, take up with a little hydrochloric acid, and precipitate with ammonia. REPORT ON INSECTICIDES AND FUNGICIDES". By QO. B. Winter (Agricultural Experiment Station, E. Lansing, Mich.), Referee. The cooperative work on insecticides included a study of the deter- mination of lead, copper and zinc in products containing arsenic, copper, zinc, lead, calcium and magnesium (Bordeaux-lead arsenate, Bordeaux- zinc arsenite, etc.); and a comparison of the Gyory bromate method with the official iodin method for determining arsenic when present in a hydrochloric acid solution as arsenious oxid. Lime sulphur solutions and London purple also received consideration. BORDEAUX-LEAD ARSENATE AND BORDEAUX-ZINC ARSENITE. GENERAL PROCEDURE FOR THE ANALYSIS OF A PRODUCT WHICH MAY CON- TAIN ARSENIC, ANTIMONY, LEAD, COPPER, ZINC, CALCIUM, MAGNESIUM, ETC. For the determination of lead, copper and zinc in a product which may contain arsenic, antimony, lead, copper, zinc, iron, calcium, etc., a composite product was prepared by thoroughly mixing samples of lead arsenate, zinc arsenite, and dry Bordeaux, each of which had been passed through a No. 40 sieve and well mixed. The lead arsenate used in preparing this mixture was obtained from one of the large chemical companies in Michigan. This sample was 1 Presented by A. J. Patten. 1920] WINTER: REPORT ON INSECTICIDES 135 found to contain 63.72 per cent of lead oxid. The zine arsenite was pre- pared by adding a solution of arsenious oxid to a solution of zinc sulphate, both solutions being slightly acid, and then neutralizing with sodium hydroxid solution!. The amount of zinc oxid in this preparation was determined and found to be as follows: 1. Determined as zinc sulphate and calculated to {HAYS ~ OL pees pes a 30.50 per cent 2. Precipitated as the sulphid and burned to the Osa |S! ee ee ee ee 30.90 per cent 3. Determined as pyrophosphate and calculated to emotes 235 ies Tae Ee 6 ese PO ule 1 30.60 per cent INS CLAP Cute ree ee te or re ee ee eee eee oe et 30.67 per cent The dry Bordeaux was prepared from equal parts by weight of C. P. calcium oxid and copper sulphate in the following manner: The copper sulphate was dissolved in water, the lime slaked and diluted, and the milk of lime added to the copper sulphate solution while stirring. This mixture was allowed to stand for some time, filtered by means of suction and the precipitate dried and ground. An electrolytic determination showed that the mixture contained 20.22 per cent of copper. The Bordeaux-lead arsenate was prepared by mixing one part by weight of the dry Bordeaux with two parts of the lead arsenate, passing the whole through a No. 20 sieve and mixing again. Theoretically, this compound should contain 42.48 per cent of lead oxid and 6.74 per cent of copper. The Bordeaux-zine arsenite was prepared by mixing three parts by weight of the zinc arsenite with four parts of the dry Bordeaux, passing the mixture through a No. 20 sieve and remixing. Theoretically, this should contain 13.14 per cent of zinc oxid and 11.56 per cent of copper. The Bordeaux-lead arsenate with Bordeaux-zinc arsenite was prepared by mixing equal parts of the above mixtures, passing the mixture through a No. 20 sieve and remixing. Theoretically, this com- posite sample should contain 21.24 per cent of lead oxid, 9.15 per cent of copper and 6.57 per cent of zinc oxid. The methods sent to the collaborators for determining the lead, copper and zinc in the above composite sample are as follows: GENERAL PROCEDURE FOR THE ANALYSIS OF A PRODUCT CONTAINING ARSENIC, ANTIMONY, LEAD, COPPER, ZINC, IRON, CALCIUM, MAGNESIUM, ETC. (Applicable to such preparations as Bordeaux-lead arsenate; Bordeaux- zinc arsenite; Bordeaux-Paris green; Bordeaux-calcium arsenate, etc.) 1 J. Am. Chem. Soc., 1906, 28: 1163. 136 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 1 LEAD OXID (PbO). Weigh 1 gram of the dry powdered sample, transfer to a beaker, add 5 cc. of hydro- bromic acid (sp. gr. 1.31) and 15 cc. of hydrochloric acid (sp. gr. 1.19) and evaporate to dryness to remove arsenic; repeat this treatment; then add 20 cc. of the hydrochloric acid and again evaporate to dryness. Dissolve in 25 cc. of 2N hydrochloric acid, dilute to 100 cc. and pass in hydrogen sulphid until precipitation is complete. Filter, and wash the precipitate thoroughly with N/2 hydrochloric acid, saturated with hydrogen sulphid. Save the filtrate and washings for the determination of zinc. (Antimony may be present in samples containing zinc and should be removed by digesting the sulphids with sodium sulphid.) Transfer the filter paper containing the sulphids of lead and copper to a porcelain casserole or evaporating dish and completely oxidize all organic matter by heating with a few cc. of concentrated sulphuric acid, together with a little fuming nitric acid; then completely remove all nitric acid by heating on the hot plate with sulphuric acid to copious evolution of white fumes, cool, and determine lead as the sulphate, as directed for lead arsenate’. From the weight of lead sulphate calculate the amount of lead oxid present, using the factor: PbSO, < 0.73600 = PbO. COPPER. Evaporate the filtrate and washings from the lead sulphate precipitate to fuming, add a few cc. of nitric acid to decompose the alcohol, and continue the evaporation until about 3 cc. of concentrated sulphuric acid remain. Determine the copper by Low’s titration method as directed under Bordeaux mixture, or by electrolysis as follows: ; Take up the sulphuric acid solution with water, add 1 cc. of concentrated nitric acid, and filter if necessary. Make the volume to about 150 cc. and electrolyze as usual. ZINC OXID (ZnO). Method I. Evaporate the filtrate and washings from the precipitate of copper and lead sulphids to a small volume, add 1-2 ce. of concentrated nitric acid, boil for a few minutes, then evaporate to dryness, add a few cc. of concentrated sulphuric acid and heat to fuming, take up with water, remove by filtration any calcium sulphate that may have sepa- rated out and wash with cold water. Neutralize with concentrated sodium hydroxid solution (using phenolphthalein as indicator) and then add about 15 grams of solid sodium hydroxid. Transfer to a beaker (the volume should now be about 150 ce.), heat to boiling and electrolyze, using a rotating nickel cathode, which should be placed below the anode, and a current of about 3.5 amperes. About 10 minutes before the electrolysis is completed the electrodes and the sides of the beaker should be washed down with a jet of water. The solution should be cooled to about 25°C. just before the end of the electrolysis by applying water and ice to the outside of the beaker. When the deposition is completed, which should take about 45 minutes, lower the beaker, quickly rinse the cathode with cold water, remove, and rotate for a moment in each of two vessels containing cold water, then in alcohol and, finally, in ether dried over sodium. Heat in an oven, or by holding some little distance above a free flame for a few moments, and weigh as metallic zinc. Calculate the zinc oxid as follows: Zn X 1.24476 = ZnO. 1 Assoc. Official Agr. Chemists, Methods, 1916, 68. 2 Ibid., 70. OE elt i ca 1920] WINTER: REPORT ON INSECTICIDES 137 Method ITI. Evaporate the filtrate and washings from the sulphid precipitation of the copper and lead to a small volume, add 1-2 cc. of concentrated nitric acid, boil a few minutes, then evaporate to dryness, add a few cc. of concentrated sulphuric acid and heat to fuming. Take up with water, remove any calcium sulphate that may have precipitated out by filtration and wash with cold water. Neutralize with ammonium hydroxid (using methyl red as an indicator), add 4 cc. of 5% sulphuric acid per 100 cc. of solution (the volume should be about 150 cc.) and pass hydrogen sulphid gas into the solution at room temperature for about 40 minutes. Allow to stand for 30 minutes with occa- sional stirring, filter through a tared Gooch crucible, wash with cold water, dry, burn to the oxid, preferably in a muffle at 850—-930°C., and weigh as zinc oxid. The following results were received on this sample: TABLE 1. Bordeauz-lead arsenate with Bordeaur-zine arsenite. ZINC ox1p (ZnO) LEAD OXID COPPER ANALYST (PbO) (Cu) | Method I | Method II per cent per cent per cent per cent 1. L. E. Sayre, University of Kansas, Law- | 20.51 9.10 Sa 6.50 rence, Kans. 20.49 9.04 Re 6.75 PAM CRAPO aera eosin jshoss 5 sso ois -o.s sh 20.50 9.07 ret 6.62 2. D. K. French, Dearborn Chemical Co., 20.76 9.54 Saas 6.47 Chicago, Il. 20.75 9.55 sho 6.38 21.08 9.57 Bae 6.25 20.51 9.55 mir? 6.42 LAV ECEA BOM ccicrc.d ce bsicie aha sfauiie: aes /ato'e. 01 20.78 9.55 ers 6.38 3. J. J. T. Graham, Bureau of Chemistry, 21.51 9.52 6.27 6.48 Washington, D. C. 21.55 9.46 6.40 6.52 21.62 9.54 6.34 6.34 21.47 9.50 6.35 | 6.50 21.59 setae Ba 6.40 1572722 Sg a lo a | 21.55 9.51 6.34 6.45 | 4. E. F. Berger, Agricultural Experiment Sta- | 21.23 9.19 tis 6.40 tion, E. Lansing, Mich. Sages Bee sick 6.56 a ee ce ee ee ee [pee e ree TN. 6.50 INVGrapEs. Sag icous Se ee 21.23 Hee ee! 6.49 5..0. B. Winter, Agricultural Experiment | 21.26 9.10 5.14 6.55 Station, E. Lansing, Mich. 21.26 9.20 5.38 6.70 se: Se 9.35 Guth C OFNO B OE CSIR EEEC Rae aeRO RRO TERY CRE ACH eTET OT evo een 34.96 34.96 Bie awe SOL CE OE ne eae oy he eso Nae ES) ee oe 32.66 32.70 These determinations were made with the one instrument, a Féry refractometer made by Adam Hilger, London, England. Results by one observer on ten samples using the Abbé and the Féry instruments were reported by Snell and Scott? in 1914 and showed close agreement. Sherwood is of the opinion that the refractometer method is quite accurate in the case of maple sirup. A. H. Bryan also pointed out the advantages of this method of estimating dry substance in maple sirup as well as in most other liquid saccharine products. In twelve out of thirteen samples he obtained higher results for moisture by the refrac- tometer method than by drying 3 to 5 grams on 10 to 15 grams of sand in a flat-bottomed dish at 70°C. in a vacuum oven until the loss in 5 hours did not exceed 3 mg. : MOISTURE BY DRYING. The method of drying on sand in a vacuum oven at 70°C., prescribed for honey and tentatively adopted for all maple products, is open to criticism on the grounds of indefiniteness as to the measure of the vacuum, the times for weighing and the degree of constancy to be attained; and the inappropriateness for maple products, which ordinarily contain but little levulose. The Laboratory of the Canadian Department of Inland Reve- nue follows the practice of drying at 100°C. to constant weight, having the sugar finely powdered and spread upon a watch glass, the sirup on asbestos fiber or sand. The two tentative methods of the association for massecuites, molasses and other liquid and semi-liquid products, 7. e., 1 Assoc. Official Agr- Chemists, Methods, 1916, 126. 2 J. Ind. Eng. Chem., 1914, 6: 216. 3 J. Am. Chem. Soc., 1908, 30: 1443. ‘ Assoc. Official Agr. Chemists, Methods, 1916, 121. 160 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 drying upon pumice at 70°C. (in the absence of levulose, 100°C.), and drying upon quartz sand at 100°C., may possibly be suitable for maple products. None of these methods is regarded as quite satisfactory. With sac- charine products, absolute constancy of weight is rarely, if ever, attain- able by any method of oven drying and in none of the methods referred to are the conditions so closely defined as to yield concordant results in the hands of different analysts. In the case of sirups, the refractometer method forms a satisfactory substitute, not only giving much more accordant results, but also effecting great economy of time and labor. From the work of West! on sorghum sirup, it would appear that Danne’s calcium carbide method possesses similar advantages. Both of these methods, however, require special apparatus, and the recognition of a direct drying method is perhaps unavoidable as a concession to the laboratory of modest resources. Such a method must, however, be much more closely defined than any of those at present in use. Pro- vision must be made not merely for uniform temperature throughout the oven, but for uniform ventilation as well. In the determination of moisture in evaporated apples, J. A. Dawson (Laboratory of the Inland Revenue Department, Vancouver, B. C.) reports results differing by one to two units of percentage, depending upon whether ihe dish stood at the front or back of the shelf of an electrically heated oven of the Freas type. He also states that, in such an oven set for 100°C., he has observed variations from 97 to 103°C. in a calibrated thermometer laid hori- zontally on the shelf with its bulb in the back left corner. Such observa- tions are suggestive of the need for further improvement of the apparatus available for the determination of moisture by loss of weight by drying. The points indicated for study under this head were: (1) Comparison of drying at 70°C. in a vacuum oven and at 100°C. in a water-jacketed or electrically heated oven. (2) Quantity of sample to be used. (3) Spreading material—sand, pumice or asbestos—and in the case of sugars, omission of spreading material. EXPERIMENTS AT 100°C. Dawson made preliminary experiments upon a standard 65 per cent by weight solution of cane sugar, prepared by shaking together at 30°C., 70 grams of water and 130 grams of commercial extra fine granu- lated pure cane sugar, previously ground to pass a 40-mesh sieve, and dried for 16 hours at 100 to 110°C. The sugar used gave, after the drying, a polarimeter reading of 99.8° Ventzke. The solution obtained 1 J. Ind. Eng. Chem., 1916, 8: 31. 1920] SNELL: REPORT ON MAPLE PRODUCTS 161 had a refractive index of 1.4509 at 28°C., as measured by the Abbé refractometer. By Geerlig’s tables such a solution contains 64.52 per cent of sugar. The results obtained by drying 2 grams of this solution, plus 10 cc. of water, in a glass crystallizing dish 5.5 cm. in diameter and 3 cm. high in a Freas electric oven, set for 100°C., for exactly 4 hours, were as follows: TABLE 4. Moisture determined by different methods. (Analyst, J. A. Dawson.) SPREADING SAMPLE PLus 15 SAMPLE PLUS 5 GRAMS SAMPLE NUMBER MATERIAL GRAMS ACID-WASHED | IGNITED CHRYSOTILE OMITTED IGNITED SAND ASBESTOS per cent per cent per cent DPE erotics accyare cectere s «iss 30.84 34.32 36.19 9455.63 OCACNOEE ST CRE RS RRC CEES 30.89 34.24 (35.46) Do COU OSE CIR EOI ME SIa rare owtS E 29.86 34.42 36.10 RSE e re aNegey seca tev neue aiehare em 6) e 30.53 34.33 35.92 The sand used was fine enough to pass a 20-mesh, but not a 40-mesh sieve. It was stirred at the beginning of the experiment and after 1 and 2 hours. In the case of asbestos No. 2, it was observed that the spreading material was not in contact with more than half of the bottom of the dish and evidently some of the solution was not distributed over the fiber. Dawson infers from his results that drying with sand for 4 hours with stirring gives approximately accurate results, though possibly an addi- tional 2 hours would be better, and that drying with asbestos for 4 hours gives results about 0.5 per cent higher than true results. He hopes to continue his investigation. Van Zoeren, interpreting the term “‘to constant weight’’ literally, endeavored to realize an absolute constancy, or, at least, one not exceed- ing a change of 0.01 per cent of the original weight per hour. Finding in his experiments on Sirup No. 1 at 100°C. that such constancy was not obtainable within less than 40 hours at 100°C., he made his first weighings on the other sirups after 30 hours, his second after 40 hours, and his third after 50 hours. These experiments were made with a small electrically heated oven of Sargent’s make, an oven exhibiting much greater variations of temperature than the Freas oven. Aluminium dishes 7.5 cm. in diameter and 1.8 cm. in depth were used in some cases, and dishes of 6.0 cm. X 1.5 cm. in others. The sand was washed with hydrochloric acid and ignited. The asbestos was tremolite, such as is ordinarily used in Gooch crucibles. In all cases, 5 grams of sirup were weighed in a sugar dish and transferred to the tared dish with a small 162 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 quantity of distilled water. The results at 40 hours are given in Table 5. With one exception, they show lower percentages of dry matter than were obtained by the refractometer but, considering the long period of heating, the differences are remarkably small. TABLE 5. Determination of dry matter in sirups. (Analyst, G. J. Van Zoeren.) | DRIED 40 HOURS AT 100°C. DRIED 100 HOURs AT 70°C. UNDER ATMOSPHERIC PRESSURE. UNDER REDUCED PRESSURE. DRY SPREADING MATERIAL SPREADING MATERIAL MATTER SAMPLE NUMBER a Bh ee A ee BY REFRAC- Tremolite Sand Pumice ‘Asbestos Sand Pumice TOMETER asbestos stone stone per cent per cent per cent per cent per cent per cent per cent We oabtin cea gee: 66.84 66.62 67.69 67.42 67.36 68.29 67.37 66.79 66.69 67.76 67.78 67.34 68.24 Bei Average..... 66.81 66.66 67.73 67.60 67.35 68.27 67.37 ZSoea stewelnosies||. (04:89) 65.18 64.80 64.90 65.19 66.12 65.04 | 64.98 64.71 64.69 64.87 64.76 64.32 ppt. Average..... 64.94 64.95 64.75 64.89 64.98 65.22 65.04 Beit aeayeis aires 67.05 67.01 66.80 67.32 66.99 67.82 67.34 } 67.25 67.05 67.52 67.95 67.11 67.46 ee { Average..... 67.15 67.03 67.16 67.64 67.05 67.64 67.34 f TABLE 6. Mean variations of individual results by drying from refractometer results. SAMPLE NUMBER at 100° at 70° | Pay at 100° | at 70° | y Wesker sia, hahah + (0.54 =0.38 Asbestos —0.28 +(0.23 AN «eA = +0.21 +0.42 Sand +0.43 +0.18 3 iat sere =0.29 =0.30 Pumice +0.34 +0.70 The drying experiments conducted by the writer on sirups at 100°C. were confined to a single series in which a reboiled and cotton-wool filtered sample of Sirup No. 1 was dried on the three spreading materials and samples of Sirup No. 2, also reboiled and refiltered, were dried on asbestos. All the portions were dried at once in the same Sargent oven that Van Zoeren used, and the weight of sample and method of weighing were the same as his. For Sirup No. 2 and for the second of each pair of duplicates on Sirup No. 1, 7.5 cm. aluminium dishes were used. In all cases, the drying was more rapid in the 7.5 cm. than in the 6 cm. 1920] SNELL: REPORT ON MAPLE PRODUCTS 163 dish. Weighings were made after 5, 7, 8, 9, 10, 11, 14 and 16 hours. In the final 2 hours of drying the loss of weight per hour was less than 0.1 per cent in all the 7.5 cm. dishes and in all 6 cm. dishes except the one in which Sirup No. 1 was dried on asbestos. In that dish and the two pumice dishes, the percentages of residue at the end of the 16 hours were decidedly higher than those deduced from the refractometer obser- vations. The other asbestos portion and the two portions dried on sand gave results according closely with the refractometric indication (Table 7). On the other hand, the two sirups prepared from Sample No. 2 and dried on asbestos gave results for dry matter which, even at the end of 5 hours’ drying, were lower than those derived from the refractometer readings. Considering the inadequate control of conditions, the dis- cordance of the results obtained, and the fact that the sirups used were not the original collaborative samples, it does not appear worth while to burden the report with the details. TABLE 7. Determination of dry matter in a prepared sample of Sirup No. 1 (16 hours at 100°C. under atmospheric pressure). (Analyst, J. F. Snell.) MEDIUM SIZE OF DISH RESIDUE cm. per cent BAS OS COS MRR ors aye cnet cakes ol ale eA cen Tee be io aes Meas 6.0 67.21 ANI DES VOSS 8g OSCE RD ES Ry ST a ee RES eae Meo 66.96 ECENICE ME eee an ee eee hee shiek Meer des ed Sates 6.0 67.56 [PETTACB 6 5.b. CORO SBOE OTE HON EDS nee? eee Mee 67.30 SHC). occ 0 GROEN Sete SEC EG TERT anne oD rere Ene Sep 6.0 66.70 SHATG) 5 6 pic Rt hosts CaO Phase Cuore: Phrn oea aceon RR Re eee Ue) 66.62 ESS VELETEAGCLOINCLEL Ae By Ment dts te poke oie lobe os aloe See Riees te oe Nah 66.79 One point, however, must be mentioned. Among the fifty weighings made after the ninth hour of drying, no less than twelve showed an in- crease of weight, instead of a decrease. As the dishes were always covered during the weighings and as other dishes cooled in the same desiccator showed no similar increase, and, furthermore, as similar results were later obtained with the sugars, the only conclusion to be reached is that simultaneously with the elimination of water some chemical change (possibly an oxidation) resulting in an increase of weight is taking place. This is a question that deserves further study. EXPERIMENTS AT 70°C. The experiments at 70°C. were carried out in the Freas oven, a vacuum desiccator connected with a filter pump through a large safety-bottle being used as the vacuum chamber. In the experiments conducted by 164 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 the writer, a slow current of air, dried by passing through sulphuric acid, was allowed to flow through the chamber, and the pressures, as measured by a mercury manometer connected between the safety bottle and the vacuum chamber, were from 60 to 160 mm. Van Zoeren used the same oven and pump but a larger desiccator and admitted no cur- rent of air. He did not measure the pressures. Van Zoeren’s results at the end of 100 hours are given in Table 5. The average results are closer to the refractometer indications than are those obtained by drying 40 hours at 100°C. But when the individual results are examined, as is done in Table 6, there is but little choice between the two methods. The only experiment conducted by the writer with sirup at 70°C. was made with a reboiled and cotton-wool filtered portion of Sample No. 3. This gave 66.04 per cent of total solids by the refractometer, and the residues after 18 hours’ heating (which did not result in absolute con- stancy) were 66.18 and 66.32 per cent in two 7.5 cm. dishes, and 66.40 per cent in a 6 cm. dish. With sugars, constant weight was realized by both experimenters in about 48 hours but results were not concordant. These results, as well as those obtained with the sugars at 100°C.. are omitted on account of such discordance. WINTON LEAD NUMBER. The points indicated for study in reference to the Winton method were: (1) The advisability of substituting 25 grams of cane sugar sirup for the few drops of acetic acid in the blank determination!. (2) The advisability of reducing the results to the dry matter basis®. The results of the collaborative work are shown in Table 8. The basic acetate solution was prepared from Horne’s salt. In the experi- ments conducted by the writer the acetic acid blank was treated with a few drops of 2N acetic acid. On diluting, slight clouding ensued, but the weights of lead sulphate obtained by precipitation after settling were practically identical with those obtained from the cane sugar blanks, which remained quite clear. Van Zoeren, who added enough acetic acid to prevent precipitation, obtained 2.2 mg. less lead sulphate from these blanks than from the cane sugar blanks. The results may be interpreted as slightly favorable to the use of the cane sugar sirup. This has also a logical advantage over acetic acid, in that the substance added is identical with that which, in the case of the t J. Ind. Eng. Chem., 1913, 5: 997. 2 [bid., 1914, 6: 221. 1920] SNELL: REPORT ON MAPLE PRODUCTS 165 TABLE 8. Collaborative results on Winton lead number. ACETIC ACID BLANK CANE SUGAR BLANK SAMPLE NUMBER Van Zoeren Snell Van Zoeren Snell Desa ste acerca rete rh nape cucht vps 1.82 About 0.01 per cent 1.92 1.89 1.84 1.94 1.89 1.83 1.93 1.88 saree atieys 1.88 1.89 cee he hd be Cee 1.73 1.79 2.07 1.81 1.91 2.08 ilr(e/ 1.85 2.08 LM ee eras ai dim love 2.90 lower than with the 2.99 2.29 2.82 cane sugar blank 2.91 2.31 2.86 2.95 2.47 Bivocs 2.47 2.39 RRR elite Seis enci sie aus os 2.23 2.33 2.50 GP? 2.30 2.47 2.23 2.31 2.49 SRT et tk cea: Zoom hh ane Rsk 2 2.45 2.43 DSSS al rE tad. cechess 2.48 2.40 VARY (ee 9 | oer oye 2.47 2.42 Wo SA. Ot DH IRR REI een DAY alta onhiates 4 2.56 2.39 Aste alte 8 See. 2.47 2.36 ZSIUA ie we Yee Pee 2.52 2.38 ] maple sirup, prevents the precipitation of the basic acetate. If it were adopted, the directions would be to make a blank determination, using 25 cc. of a pure cane sugar sirup (sp. gr. 1.320) in place of the maple sirup. The question of the advisability of abandoning the reduction of Winton lead numbers to the dry basis is one which does not permit of solution upon the basis of work on a few samples. The reduction to dry basis was not a part of the original method of Winton and Kreider! and, as has been shown by Snell and Scott?, the range of variation of wet basis Winton numbers in genuine maple sirups is narrower than that of the dry basis numbers. The wet basis number is therefore a sharper crite- rion for the detection of adulteration than the dry basis. Sherwood favors the retention of the reduction to dry basis on the grounds that the difference of range is not great; analyses of maple products published by the Bureau of Chemistry and certain other in- vestigators and frequently used as bases of comparison are stated on the 1J. Am. Chem. Soc., 1906, 28: 1204. 2 J. Ind. Eng. Chem. .1913, 5: 997. 166 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 dry basis, and to discontinue the calculation of the Winton number to dry basis would tend to confusion. Opinions have not been expressed by other collaborators. The directions of the Winton lead method should be closely followed to insure correct results. The sugar solution must not be warm nor can it be poured into the lead subacetate. The following parallel results on Sample No. 5 illustrate this point: TABLE 9. Determination of lead number on Sample No. 5. DESCRIPTION OF METHOD LEAD NUMBER Regular method rrWis ai shia json eae eee 2.49 25 cc. of subacetate solution, measured into a flask, sirup added and ‘washed in wathiwaterwsccas 6 paki evany oan ee ania Rie 2.69 2.26 CANADIAN LEAD NUMBER. The Laboratory of the Canadian Inland Revenue Department has for many years used this value as the chief criterion for the discrimina- tion of genuine and adulterated maple products. The directions for its determination, as approved by A. Valin of that laboratory, are as follows: Weigh the quantity of sirup containing 25 grams of dry matter, transfer to a beaker, add 50-75 cc. of water, boil gently for 2-3 minutes, transfer to a 100 cc. flask, cool and make up to the mark. Pipette 20 cc. of this solution into a large test tube, add 2 cc. of lead subacetate solution (sp. gr. 1.26) and mix. Allow to stand 2 hours, filter through a tared Gooch, wash four or five times with boiling water, dry at 100°C. and weigh. Multiply the weight of the dry precipitate by 20. The points indicated for study were: (1) The advisability of weighing 25 grams of sirup instead of the quantity of sirup containing 25 grams of dry matter. (2) The necessity for boiling the diluted sirup if all samples have been boiled in the preparation for analysis. (83) The advisability of substituting 1.25 for 1.26 as the density of the subacetate solution. (4) The advisability of defining the volume of wash water and allow- ing more license as to temperature’. (5) Variations between duplicates. The collaborative results are given in Table 10. Van Zoeren and the writer used a subacetate solution (sp. gr. 1.25) prepared from Horne’s 1J. Ind. Eng. Chem., 1913, 5: 996. ———————— 1920} SNELL: REPORT ON MAPLE PRODUCTS 167 salt. They also used a 100 cc. beaker in place of the large test tube. The subacetate solution was added from a burette. The writer washed the solution as directed without close attention to the quantity of wash water. Van Zoeren always washed the solution with exactly 100 cc. of boiling water. It should be noted that the mat of asbestos in the Gooch crucible in this determination needs to be heavier than for most other precipitates. Inattention to this detail and to the exact volume of the wash water may possibly account for the inferior agreement of the writer’s duplicates as compared with those of the other collaborators. TABLE 10. Collaborative results on Canadian lead number. COLLABORATORS | USING 25 GRAMS SIRUP AND CALCULATING TO DRYNESS SAMPLE NUMBER Valin Van Zoeren Snell Vv an Zoeren 1 5 doc. AeCneio Sea 2.20 2.51 2.55 1.96 2.24 250 2.04 1.93 2.20 2.49 2.28 1.74 2.18 sone Sa 1.68 Average: Js. oeete cs 35. 2.20 2.52 2.29 1.83 TSS bade reaper orcs oases 2.22 2.52 2.24 1.69 2.22 2.48 2.23 1.72 2.08 = Ss sis 2.22 PAMCLARE St. Syoccici= claxesaies 2.19 2.50 2.24 1.71 eet Ne ctiowe es EE. 3.22 | 4.04 4.30* 3.76 3.24 4.01 3.94 3.56 3.16 4.07 3.59 3.40 3.16 3.92 3.73 3.46 LGR eee eee 3.19 4.01 3.75 3.54 Go ot oe SOO RRR eae 2.84 3.12 3.12 2.83 2.74 3.15 3.35 a 2.80 ef oie bs 2.70 AVE ARE Sita elias «i 20a 3.14 3.24 2.83 3). oc doe. SORTGER CECE 3.22 3.31 3.52 3.16 3.06 3.36 3.42 3.08 3.10 3.32 3.18 3.20 3.32 3.16 LOG aa eee 3.14 388) 3.47 3.15 Rey trets css get sice ns 3.16 3.32 3.33 3.07 3.14 3.29 3.23 3.17 3.08 at aa 3.06 = PRY CEQ Eero ae Narn(aJa seis 3.11 3.31 3.28 3.12 * Not included in average. 168 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 Valin admits that it would be more convenient to weigh 25 grams of sirup instead of 25 grams of dry matter, but states that the Laboratory of the Canadian Inland Revenue Department follows the other pro- cedure in order to have a uniform standard for sirup and sugar. In the process of this association in which the sugar is converted into sirup for analysis, this object is attained in another way, and the only objection to adopting the procedure with 25 grams of sirup is that the results so obtained would not, even after reduction to a dry basis, be comparable with those which the Laboratory of the Canadian Inland Revenue De- partment now publishes. On the other hand, they would be comparable with the results which that laboratory has published upon a large num- ber of genuine sirups'. This is not made clear in the publication itself, but in answer to an inquiry, the Chief Analyst advised the associate referee under date of February 17, 1913, that the lead determinations were made on 5 grams of the sirup, and the results were later calculated to a dry basis. The wide difference which usually exists between dry basis results obtained with the use of a definite weight of sirup and those obtained with the quantity of sirup containing that definite weight of dry matter has been pointed out by Snell and Scott? and is further illustrated by results obtained by Van Zoeren on the present collaborative samples, particularly on Samples 1 and 4 (Table 10). In all cases, his results, using 25 grams of sirup, are lower than those using 25 grams of dry substance. This is consistent with the work of Snell and Scott and is what one would expect in view of the solvent action of sugar upon the precipitate. It is notable, however, that in four instances out of six, the results with 25 grams of sirup are equal to or greater than Valin’s results obtained with the use of 25 grams of dry substance. This is doubtless only a detail of the more general fact that Valin’s results as a whole are lower than those of the other collaborators. Whether this is due to a difference in the lead subacetate solutions used, or to some variation in the procedure, is not known. The only results bearing on the question of the necessity of boiling the diluted sirups when they have been previously boiled in the prepara- tion of the sample are those of the associate referee on Sirup No. 2. A portion of this sirup, prepared for analysis by boiling to 104°C. and filtering through cotton wool, gave 3.60 and 3.50 as the Canadian lead number without reboiling, and 3.22 and 3.44 when the sirup was reboiled after dilution. Valin is of the opinion that the use of subacetate solution of specific gravity of 1.25 instead of 1.26 would make no difference in the results. * Can. Lab. Inland Rey. Dept., we 228: (1911). * J. Ind. Erg. Chem., 1913, 5: 1920] SNELL: REPORT ON MAPLE PRODUCTS 169 Since the former strength is now commonly used in clarifying for the polariscope, its use is to be recommended on the score of convenience. Further study on the Canadian lead method is strongly recommended since this method is so simple and possesses the advantage that in adulterating with refined sugar the values fall off more rapidly than the percentage of maple sirup’. ASH VALUES. Van Zoeren and the writer have done considerable work on the ash values but as no results from collaborators were received our results are reserved for later publication. OTHER METHODS. The electrical conductivity method? should be further tested before it receives official recognition. It is a very simple, rapid test. In the writer’s laboratory, it has given results of a more restricted range in genuine sirups than any of the recognized methods. For collaborative purposes, it might perhaps be well to dilute the sirups to a more definite sugar content than is directed for the rapid test, but whether the increase of accuracy would compensate for the loss of time is a point that would require study. The volumetric lead method has not given satisfactory results with the present samples. With sirups of high quality, there is sometimes room for difference of opinion as to the plotting of the graphs. RECOMMENDATIONS. It is recommended— (1) That work on the preparation of the sample be continued with a view to revision of the directions. (2) That collaborative work be done on the Winton lead number. (8) That the Canadian lead number and conductivity value methods be further studied collaboratively with a view to their adoption. (4) That work on the determination of moisture and ash be resumed when these topics are under study in reference to other saccharine products. 1J. Ind. Eng. Chem., 1913 5: 995. 3 Tbid., 1916, 8: 331. 3 Ibid., 1916, 8: 241. 170 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 REPORT ON HONEY. By Sipney F. SHerwoop! (Bureau of Chemistry, Washington, D. C.), Associate Referee. The report includes a study of honeydew honeys, mixtures of honey- dew and glucose, and normal honey and glucose with the object of ascertaining methods of differentiating between honeydew and normal honeys and mixtures of these products containing glucose (this problem is discussed at length by Browne?). It will be noted that honeydew exhibits a high plus polarization at 20°C. and at 87°C., both before and after inyersion. Since it was observed that normal honey usually gives a very slight precipitate with basic lead acetate, while honeydew usually gives a very copious precipitate (glucose giving a very slight or no precipitate), it was thought that a study of the application of the Winton lead number? might prove this determination to be of value. The application of this determination to typical honeydew honeys gave values at first of 2.81 . to 3.06. However, in one case, a value of 0.32 was found and, as this is lower than the values found in certain normal honeys, the investigation of the lead number was discontinued. Since Kénig and Karsch? called attention to the fact that after pre- cipitating the dextrins with absolute alcohol, natural honeys exhibit leyorotation while honeys containing 25 per cent or more of glucose exhibit dextrorotation, and since this method was found of confirmatory value by Browne?, it has been applied to various honeydew honeys and mixtures of honey with glucose with the following results: Polarization* of honeydew honeys before precipitation with alcohol. INVERT DIRECT Repl DESCRIPTION OF SAMPLE 20°C. Sie ae. 1 Hone yd ew,..25: hia: ue nays CL aOR oe eee + 6.80 | + 5.80 | +26.00 2 Honeydew ..o25 . cee te ee A Le eee + 5.70 | + 2.00 | +23.40 3 IONE Yew ee he era ee ee eae +13.40 | + 9.20 | +30.60 4 Honeydew cies. ee ee ee eee +14.70 | +10.40 | +31.60 5 Honeydew No. 1 + 20 per cent glucose......| ...... | .-.... | --..-- 6 Honeydew No. 2'-++ 20 per cent glucose: <=. :|/9225 0) |) Sten eens * All polarization figures are stated on a basis of 20 grams of the original honey in 100 cc. of water; readings in a 200 mm. tube. ‘ Present address, Bureau of Plant Industry, Washington, D. C. 2?U.S. Bur. Chem. Bull. 110: (1908). 3 J. Am. Chem. Soc., 1906, 28: 1204. * Z. anal. Chem., 1895, 34: 1. 1920) MATHEWSON: COLORING MATTERS IN FOODS 171 Polarization* of honeydew honeys and mixtures of honeydew honeys and glucose after precipitation with alcohol. INVERT DIRECT ae DESCRIPTION OF SAMPLE 20°C: | sate — 1 Honeydews.- ss ices cose ose fasten tema —2.70 —3.52 +2.09 2 Honeydew: soc... 2n2et- aes fe Aaicad nee —3.30 —4.24 +1.98 3 FIDE YOEW 220th es.3 3) Bae wit nts Gislete ot. Tee ea ee —2.20 —2.80 +1.98 4 VON GY Ge Wes irae ties Sees Mere inter Sats Soe tee —2.00 | —2.70 | +2.42 5 Honeydew No. 1 + 20 per cent glucose......| +0.75 +0.28 +3.19 6 Honeydew No. 2 + 20 per cent glucose... ... +0.30 —0.33 —2.86 * All polarization figures are stated on a basis of 26 grams of the original honey in 100 cc. of water; readings in a 200 mm. tube. In view of the slight values for the plus polarizations of the mixtures and of the small variation between these. values and the values for the honeydew honeys, it is thought that this method, in the case of the addition of small amounts of glucose, is of minimum value only. Investigation of the precipitate thrown down by alcohol was begun but, owing to lack of time, was discontinued. It is believed that a study of this precipitate may prove of value in connection with the problem. No report on sugar house products was made by the associate referee. No report on food preservatives was made by the referee. REPORT ON COLORING MATTERS IN FOODS. By W. E. MatHewson (Bureau of Chemistry, Washington, D. C.), Referee. The work was restricted to the consideration of tests for some of the more common natural coloring substances. The qualitative differentia- tion of the various natural coloring matters found in food products can scarcely be carried out satisfactorily until much more work has been done, but many tests are in use that have been found reliable and con- venient. The Committee on Editing Methods of Analysis arranged some of the best known of these tests in the form of a table'. This table is somewhat incomplete, chiefly where tests are concerned in which no definite color change takes place. It was requested that the collaborators make tests with such samples of coloring matters as were available, so that for every case a definite 1 Assoc. Official Agr. Chemists, Methods, 1916, 166. 172 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 statement might be given in the table, concerning the behavior of the reagents and coloring matters with each other. Attention was also called to tests depending on the treatment of an acetic anhydrid solu- tion of the coloring matter with concentrated sulphuric acid and with other reagents; and to the work of Palmer and Thrun! relative to the behavior of the natural coloring matters of butter and oils with ferric chlorid and other reagents. The following comments were received from Leonard Feldstein, U. S. Food and Drug Inspection Station, Tabor Opera House Building, Denver, Colo.: The results obtained in the cooperative work on food colors at this laboratory are as follows: Hydrochloric acid with alkanet produces no change. Sodium hydroxid with annatto causes fading of the yellow color and the production of a light brown color. Ferric chlorid decolorizes alkanet, leaving a turbid dark solution. It produces no change with carotin, and turns anthocyans (cherries) deep purple. Alum solution produces a slight purple color with alkanet; turns cochineal and anthocyans (cherries) purple-red, and has no action on annatto, carotin or caramel. Uranium acetate with Brazil wood produces a deep purple-red color; no change is noticed with annatto or caramel. Acetic anhydrid and sulphuric acid produce a green fluorescence in the red color of Brazil Brood a yellow color is produced with cochineal. No action is noticed with caramel. It would appear that reference should be made in the tentative methods to the tests for the detection of carotin in butter since the action of ferric chlorid and carotin, whether alone or in the presence of fats and oils, appears to be different from that in aqueous solution. Water seems to retard the reducing action of carotin on ferric chlorid; at least no change is visible. When a crystal of ferric chlorid is added to dry carotin extract, the ferric chlorid is changed. If water is then added to the mixture, a wine colored solution is produced. REPORT ON METALS IN FOODS. By Davin Kuen? (Division of Foods and Dairies, Illinois Department of Agriculture, 1410 Kimball Building, Chicago, IIl.), Referee. TIN. A study was made of a volumetric method for tin, the essential fea- tures of which were suggested by W. B. D. Penniman, Baltimore, Md. Broadly outlined, the method consists of extracting the tin with hydro- chloric acid, the tin is precipitated from this solution by zinc, the mixed metal residue is dissolved in hydrochloric acid in the absence of air, and this solution is titrated with standard potassium iodate. The advantages over the provisional methods are the elimination of the acid digestions 1 J. Ind. Eng. Chem., 1916, 8: 614 2 Present address, The Wilson Laboratories, Chicago, II. ° 1920] KLEIN: REPORT ON METALS IN FOODS 173 and of the sulphid precipitation. Furthermore, potassium iodate solu- tion maintains a constant strength, and is, therefore, preferable to the variable iodin solution used in the provisional methods. The oxidation of stannous chlorid by potassium iodate is an interesting reaction, which may be assumed to occur in the following steps: (1) 4 KI0O3;+12SnCl, + 28 HC] = 12 SnCl, + 4 HI+12 H.0+4 KC (2) KIO;+- 6 HC] = ICl+4 Cl + 3H.0 = KCl (3) 4HI+ 4) = 4HC]+ 4] (4) KIO;+ 41+6HCl = 51Cl+3H.0 + KCl 6 KIO;+36 HCl+ 12 SnCl, 12 SnCl, + 6 IC]+-18 H.O+6 KCl KIO3;+ 6HCI+ 2SnCk = 2SnCl,+ ICl+ 3H.0+ KCl If equation (1) goes to completion before the action represented by equation (2) begins, then it will be possible to use starch as an end point indicator, for, as soon as reaction (1) is completed, further addition of potassium iodate will liberate free chlorin. This, in turn, will displace the iodin from the hydriodic acid of equation (1), according to equation (3). Continued addition of potassium iodate will convert the liberated iodin into iodin monochlorid. This action can be traced by the decol- orizing of chloroform, since iodin monochlorid does not impart color to chloroform. Thus two end points may be used. However, it has been found that the chloroform end point is not always satisfactory. With certain lots of zinc, the pink color of the chloroform was not discharged, even when a large excess of potassium iodate was added. At times the coloring matter of the original food material was carried along, and imparted a decided color to the final solution. In such cases, the chloro- form end point was unreliable. For these reasons, the chloroform end point was discarded. The sensitiveness of the starch end point is dependent upon the con- centration of the iodin liberated in equation (3), since an appreciable concentration of iodin is necessary to develop the color in starch’. Where a small amount of tin is being titrated, it is conceivable that the amount of hydriodic acid formed would be insufficient to liberate the minimum quantity of iodin necessary for the development of the blue color with starch. This condition should be remedied by increasing the concentra- tion of hydriodic acid, as by the addition of potassium iodid. Then the sensitiveness will be dependent only upon the concentration of the chlorin derived from equation (2). These theoretical considerations have been fully verified experimentally. For example, no blue color is formed, when solutions containing as much as 4 mg. of tin in 125 cc. of liquid are titrated with potassium iodate (1 cc. = 0.001 gram of tin). On the other hand, when potassium iodid was added, a sharp end point was obtained with as little as 0.0001 gram of tin. 1 J. Am. Chem. Soc., 1908, 30: 45. 174 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 TABLE 1. Effect on starch end point of the addition of potassium iodid. CONCENTRATED ZINC ZINC HYDROCHLORIC TIN ADDED POTASSIUM TIN CORRECTED POWDER USED ACID USED IODID ADDED RECOVERED FOR BLANK grams cc. gram mg. gram gram E 6 25 0.0030 50 0.0035 0.0029 E 6 25 0.0000 50 0.0006 0.0000 E 6 ae 0.0010 50 0.0016 0.0010 D 6 25 0.0000 100 0.0001 0.0000 D 6 25 0.0003 100 0.0004 0.0003 E 6 20 0.0050 100 0.0055 0.0049 E 6 25 0.0100 100 0.0104 0.0098 E 6 25 0.0100 100 0.0104 0.0098 TABLE 2. Effect of varying conditions of temperature and concentration of acid on the amount of tin precipitated. VOLUME | TIN ADDED Bn Se REMARKS ce. gram gram gram 100 0.0000 0.00095 0.0000 Precipitated hot, 70-S0°C., stood over- 100 0.0000 0.0010 0.0000 night. 85 0.0200 0.0202 0.0193 85 0.0200 0.02035 0.0195 85 0.0050 0.0057 0.0048 Precipitated hot, stood 1 hour, 70-80°C. 150 0.0400 0.0404 0.0395 Boiled 1 hour. 150 0.0400 0.0404 0.0395 150 0.0400 0.0408 0.0399 150 0.0400 0.0408 0.0399 150 0.0400 0.0408 0.0399 150 0.0400 0.0408 0.0399 150 0.0400 0.0409 0.0400 150 | 0.0400 | 0.0406 | 0.0397 | Precipitated near 100°C. 150 0.0400 0.0404 0.0395 150 0.0400 0.0404 0.0395 150 0.0400 0.0409 0.0400 150 0.0400 0.0410 0.0401 Diluted with 100 cc. of air-free solution 150 0.0400 0.0410 0.0401 before titration. 250 0.0000 0.0006 0.0000 0.10 gram of ferric chlorid diluted to 100 250 0.0000 0.0005 0.0000 ec. air-free solution before titration. 250 0.0400 0.0400 0.0395 0.10 gram of ferric chlorid. Boiled 1 hour. 250 0.0400 0.0406 0.0400 : 250 0.0400 0.0405 0.0400 125 0.0010 0.0000 0.0000 Titrated without potassium iodid. 125 0.0020 0.0000 0.0000 125 0.0030 0.0000 0.0000 125 0.0050 0.0060 0.0051 1920] KLEIN: REPORT ON METALS IN FOODS 175 The experiments in Table 2 show the efficiency of zinc in precipitating tin from an aqueous solution acidified with hydrochloric acid, under different conditions of concentration and temperature of precipitation. Twelve grams of the same lot of zinc powder were used for each experi- ment. Where ferric chlorid is indicated, it means that tin was precipi- tated in its presence. In each case 24 cc. of hydrochloric acid were used. PROPOSED VOLUMETRIC METHOD. REAGENTS. (a) Standard tin solution —Dissolve 1 gram of tin, hammered into a thin ribbon and cut into narrow strips, in 150 cc. of concentrated hydrochloric acid. Make up to 1 liter with water. (b) Standard potassium iodate solution —Dissolve 0.6010 gram of the pure salt in water and make up to 1 liter. One cc. of this solution is equivalent to 1 mg. of tin. (C) 0.5% potassium iodid solution. (d) Air-free wash solution—Dissolve 20 grams of sodium bicarbonate in 2 liters of boiled water and add 40 cc. of concentrated hydrochloric acid. This solution should be freshly prepared before use. (@) Starch paste—Preferably prepared as directed by Treadwell-Hall'. (f) Zine (20 mesh powder).—Its efficiency in completely precipitating tin from solu- tions containing organic matter must be determined for each lot. A blank should be run on all lots. DETERMINATION. Fifty grams of the sample are usually sufficient. Digest at 70°C. for an hour with an equal bulk of concentrated hydrochloric acid. If the sample contains much sugar, the digesting liquid should not contain more than 10 per cent of acid. Dilute sufficiently (about one-half) to prevent hydrolysis of the filter paper, transfer the mass to a large Biichner funnel and filter by suction. Return the filter paper and residue to the original beaker, redigest with half the volume of concentrated acid originally used. Filter as before, wash the residue with hot dilute hydrochloric acid, unite the filtrates and proceed as follows: Neutralize the filtrate with strong ammonia in a 1000 cc. beaker, add 20-24 cc. of concentrated hydrochloric acid and heat to 70-80°C. on the water bath, then add 12 grams of zinc. Allow the action to run almost to completion or until only a very small amount of hydrogen is evolved. Remove the beaker from the water bath and add ammonium hydroxid until zinc hydroxid just persists, or to alkalinity if no precipitate forms. Filter the remaining zinc and precipitated tin through a Caldwell crucible containing an asbestos pad. Wash the metallic residues with hot water made slightly ammoniacal. Transfer the detachable asbestos pad and residue to a 300 cc. Erlenmeyer flask, the crucible being wiped out with a moist piece of asbestos. Attach the flasks in duplicate, as described below, to a large carbon dioxid generator? or, more conveniently, to a tank of liquid carbon dioxid. Pass the gas through a scrubber containing water, and divide into two branches by means of a Y tube. A stream is led into each flask by means of rubber tubing and a bulbed glass tube so adjusted in the 2-holed stopper that its lower end shall be near the surface of the liquid which is to be subsequently added. 1F. P. Treadwell. Analytical Chemistry. Quantitative Analysis. Translated from the German by William T. Hall. 5th ed., 1904, 2: 513. 2 A slight modification of the apparatus described in J. Assoc. Official Agr. Chemists, 1915, 1: 258. 176 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS | Vol. IV, No. 2 The carbon dioxid leaves the flask by a second bulbed tube, the opening of which is near the top of the flask. This glass tube is connected by a long rubber tube to a second glass tube, preferably a reversed adapter, which is immersed in a cylinder con- taining water. A 50 cc. dropping funnel is passed through the stopper of each flask. After the flasks are connected, displace the air by a vigorous stream of carbon dioxid, then run in, cautiously to avoid excessive foaming, 50 cc. of concentrated hydrochloric acid through the dropping funnel. As soon as the action is over, heat the flasks to boiling while a steady stream of carbon dioxid is being passed through the apparatus. A convenient means of heating the flasks is a hot plate, made from an ordinary skillet and a Jewel burner. As soon as all the metallic particles are dissolved, remove the hot plate and substitute a cooling bath of tap or ice water. The stream of carbon dioxid should be momentarily increased, in order to prevent back suction. When cool, disconnect the flasks one at a time, and wash the tubes, stopper and sides of the flasks with air-free wash solutions. If the contents of the flasks are dark and make the end point uncertain, dilute with air-free wash solution, add 4-5 ce. of potassium iodid and 20 cc. of starch solution. Titrate at once with standard potassium iodate to a strong blue color. The method was applied to various food products, with results indi- cated in the following tables. Considerable difficulty was experienced with sugar solutions, owing to the formation of a black gummy precipi- tate during the precipitation of the tin by the zinc. This was obviated in a large measure by reducing the amount of hydrochloric acid. When the product is highly colored, it often happens that the coloring matter is carried through the entire procedure, and may mask the blue color of the end point. However, the addition of potassium iodid permits of liberal dilution of the solution, and the production of a satisfactory end point. EXPERIMENTAL RESULTS. SUGAR. TABLE 3. Determination of added lin in simple sugar solution. CONCENTRATED IN SUGAR HYDROCHLORIC TOTAL VOLUME ae Added Found grams cc. ce. gram gram 20 20 440 0.07932 0.0783 20 20 440 0.07932 0.0780 20 6.7 140 0.03966 0.03936 20 20 420 0.03966 0.03936 20 20 420 0.03966 0.03990 20 20 420 0.03966 0.0396 POTTED CHICKEN. Fifty grams portions of the same lot of thoroughly mixed material were used. 1920] KLEIN: REPORT ON METALS IN FOODS 177 TABLE 4. Determination of tin in canned potted chicken by the proposed method with a study of extraction details. FIRST SECOND THIRD EXTRAC- EXTRAC- EXTRAC- TOTAL TIN ADDED RECOVERED) TION TIN | TION TIN | TION TIN FOUND TIN TIN REMARKS FOUND FOUND FOUND gram gram gram gram gram gram 0.00471 | 0.00048 | 0.00006 | 0.00525] ......] ...... First extraction 200 ce. 0.00426 | 0.00036 | 0.00006 | 0.00468 | ......] ...... of hydrochloric acid (1 0.00456 lost O:00012)|- 25.05. - Sy sek cok [ee tercvats to 1); second and third extractions 100 cc. of the same solution. 0.0430 | 0.0008 | ...... 0.0438 | 0.03966 | 0.0388 | First extraction 200 ce. 00483) | 0:0008 |... ..: 0.0441 0.03966 | 0.0391 of hydrochloric acid (1 0.0430 | 0.0007 ...... | 0.0437 | 0.03966 | 0.0387 to 1); second extrac- tion 100 cc. of the same solution. go m0 oll) Cee oe eee 0.02436 | 0.01938 | 0.01936 | Two extractions only, te ...... | ...... | 0.05436 | 0.04963 | 0.04936 each with 100 cc. of hydrochloric acid (1 to 1). Tin was deter- mined in the combined filtrates. To 50 gram portions of the same material, potted chicken, varying amounts of tin, 2 to 20 mg., were added. TABLE 5. Determination of tin in canned potted chicken by the tentative volumetric method*. TIN ADDED FOUND DIFFERENCE TIN ADDED FOUND DIFFERENCE gram gram gram gram gram gram 0.02000 0.02493 0.00493 0.01000 0.01578 0.00578 0.02000 0.02438 0.00438 0.00500 0.00921 | 0.00421 0.02000 0.02370 0.00370 0.00500 0.00978 0.00478 0.02000 0.02395 0.00395 0.00200 0.00663 | 0.00463 0.01000 0.01431 0.00431 0.00200 0.00626 | 0.00426 * Assoc. Official Agr. Chemisls, Methods, 1916, 173. PINEAPPLE. To a 50 gram sample of the juice of canned pineapple a known volume of standard tin solution was added. The sample was then digested with 50 cc. of concentrated hydrochloric acid and 250 cc. of water. TABLE 6. Determination of tin in canned pineapple. TOTAL FOUND ADDED RECOVERED gram gram gram 0.04938 0.03966 0.03870 0.04953 0.03966 0.03885 0.01068 0.0000 0.0000 0.04953 0.03966 0.03885 178 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 RASPBERRIES. Red raspberries were poured from a large can, well lacquered on the inside, upon a colander, and the free sirup, 60 per cent of the whole, separated from the berries. The large amount of sugar present and the strong color of the material carried down during the precipitation, made it a very unpromising material from which to precipitate tin with zinc. Measured volumes of standard tin solution were added to 50 gram samples and digested with hydrochloric acid. The tin was precipitated with 12 grams of zine powder. The action was allowed to go on until the originally red solution be- came colorless. The following table gives the per cent of strong hydro- chloric acid in the solution used in digesting the samples, volume of solution from which the tin was precipitated, the tin added and recovered. TABLE 7. Determination of tin in canned raspberries. Srrvup SrrarneD BERRIES pele Volume of al aie Volume of = nual solution 4 |p aaon | acid solution..|——; |, __.1| 5 ate Added Recovered Added Recovered per cent ce. gram gram ; per cent cc. gram gram 10 400 0.0150 0.0142 28 230 0.0300 0.0299 10 400 0.0300 0.0299 41 295 0.0450 0.0462 10 400 0.0450 0.0439 30 245 0.0450 0.0466 15 400 0.0150 0.0141 26 245 0.0450 0.0448 15 400 0.0450 0.0430 26 245 0.0450 0.0441 26 245 0.0000 0.0000 26 245 0.0000 0.0001 The following results were obtained in the course of routine examina- tion of several canned products: TABLE 8. Comparison of tin recoveries by the tentative and proposed methods. TENTATIVE SUBSTANCE YOLUMETRIC PROPOSED METHOD METHOD parts per million | parts per million Pumpkin; 3:54.00 06s kee Son sweeties cee Paes 259 250 Sweeb potatoes,.:..o..0.. eeneeaee eae en ee eee 228 213 Sweet potatoes. ; ..5...s)2.2 S25 eons eee eee gems 278 266 Cider y 5. NaS e es sae eee a Ae eee 333 244 Cader’) 252 o haa es are OE ae 244 All of the above experimental work was performed by J. Zavodsky, Division of Foods and Dairies, State Department of Agriculture, Chi- cago, Ill. 1920] BIGELOW: REPORT ON CANNED FOODS 179 SUMMARY. 1. A critical study has been made of a method for the determination of tin suggested by Penniman, Baltimore, Md. 2. This method yields results comparable with those obtained by the tentative methods. 3. The new method avoids the objectionable nitric-sulphuric acid digestion, and the hydrogen sulphid precipitation. It requires less time than either of the tentative methods. ARSENIC. Some preliminary experiments were conducted in an endeavor to get a satisfactory method for arsenic in gelatin. In view of the unsatis- factory results last year with acid digestion, further attempts along similar lines were abandoned for the present. Instead, attention was devoted to the possibility of adapting the arsenic trichlorid distillation method to gelatin and other products. This work has been interrupted very frequently and not enough has been done to warrant any state- ment regarding the feasibility of this method. RECOMMENDATIONS. It is recommended— (1) That the Penniman method for tin be made the subject of collabo- rative work during 1918. (2) That the Gutzeit method as modified during 1916 be made the subject of collaborative work on baking powder materials during 1918. (3) That a study be made of methods for the determination of arsenic in gelatin and similar products. (4) That a study be made of methods for the determination of zinc, copper, and aluminium in foods. No report on fruits and fruit products was made by the referee. REPORT ON CANNED FOODS. By W. D. Brcetow (National Canners Association, 1739 H Street, Washington, D. C.), Referee on Canned Vegetables. No systematic work was done on this subject. The laboratory of the referee gave further attention to tomato products which formed the subject of the last report!. The results are confirmatory of those re- ported a year ago. During the last year the referee has given careful consideration to the possible scope of the subject of canned foods in this association 1 J. Assoc. Official Agr. Chemists, 1920, 3: 453. 180 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 and has consulted with many others regarding it. As the result of this deliberation, it does not appear that the subject of canned foods lends itself to the work of this association in the same way as many of the other subjects that have been studied. The methods employed for the examination of canned foods are largely the same as are employed for fresh foods and those preserved by other methods. The majority of topics, therefore, that might otherwise come within this field have been classified under other topics in the methods of this association. Those methods which are peculiar to caaned foods, such as methods for the examination of the can, the consistency, character, and quality of the product, do not lend themselves to cooperative work and probably are not available for study in the association. If it is the desire of the association, a description of these methods as far as they have been formulated will be presented at a future meeting. REPORT ON CEREAL PRODUCTS. By J. A. LeCuerc! (Bureau of Chemistry, Washington, D. C.), Referee. The work outlined by the referee followed closely the 1916 recom- mendations of Committee C*®. In addition to this, the collaborators were asked to make an ash determination, comparing the official method with the calcium acetate method, in which the amount of calcium acetate was reduced to a minimum, t. e., 2.5 mg. per 5 grams of flour. The moisture determinations were confined to a comparison of the official method of drying in a vacuum water bath with the so-called calcium oxid method, the drying being done, in the latter case, in a vacuum desiccator. The gluten determinations consisted in comparing the results obtained by using ordinary tap water, distilled water containing 0.1 per cent of sodium chlorid, and distilled water. The soluble carbohydrates were determined by the Bryan, Given and Straughn method’, and the results compared with those obtained by hydrochloric acid extraction, using 0.5, 1, and 2 per cent hydrochloric acid, respectively. The cold water extract was studied by comparing the extraction at 10°C. for 45 minutes with extraction at 10°C. for 1} hours and with an extraction at 5°C. for 45 minutes. The quantitative determination of chlorin was studied by two methods—the gasoline extraction method which was used last year, and the extraction in a Johnson fat extractor with alcohol-free ether. 1 Present address, Miner-Hillard Milling Co., Wilkes-Barre, Pa. * J. Assoc. Official Agr. Chemists, 1920, 3: 532. 3 Assoc. Official Agr. Chemists, Methods, 1916, 109. Sees 181 1920) LECLERC: REPORT ON CEREAL PRODUCTS TABLE 1. Determination of moisture and ash. * Assoc. oiiexat Agr. Chemists, Methods, 1916, 79. Ibid., 18 U. S. Bur. Chem. Bull. 107, § Dried in hydrogen. rev.: (1912), 21. TABLE 9 MOISTURE ASH ANALYST Oficial Vacuum Official Calci e method? (c gnem od d) Deehiontt Satamethiodt per cent per cent per cenl per cent F. C. Atkinson, American 12.70§ 12.40 0.464 0.484 Hominy Co., Indianapolis, 12.80§ 12.45 Looe Bes: Ind. R. M. Bohn, Bureau of Chem- | 11.40 12.35 0.442 0.452 istry, Washington, D. C. 11.43 12.52 0.446 0.462 C. D. Garby, Bureau of Chem- 12.90 12.85 0.448 0.432 istry, Washington, D. C 12.91 12.77 0.448 0.434 K. J. Osterhout, Bureau of | 11.82 12.12 0.476 0.472 Chemistry, Washington, D.C. 11.69 11.77 0.464 0.476 Bete atte 0.470 rite Determination of soluble carbohydrates and cold waler exiract. SOLUBLE CARBOHYDRATES COLD WATER EXTRACT Bryan, | 0.5 per 1 per 2 per ANALYST Given cent cent cent 45 1s 45 and hydro- hydro- hydro- minutes hours minutes Straughn| chloric | chloric | chloric 10°C. 10°C, bees method* acid acid acid per cent | percent | percent | per cent || per cent | per cent | per cent Pep WN BONN. < s-.5 .teres 1.39 1.53 1.45 1.59 4.09 5.22 5.08 1.39 1.43 1.40 1.47 4.24 5.28 5.25 Ree Garbyc- certs a4: 1.24 1.60 1.37 1.39 5.50 5.45 4.71 ae 1.54 1.31 1.31 x 5.54 4.83 K. J. Osterhout......... 1.28 | 163 | 1.63 | 182 || 532 | 584 | 5.23 1.41 esis 1.58 1.83 5.20 6.00 5.16 Rea. Atkinson. 52.0)... Le 6.02 5.00 * Assoc. Official Agr. Chemists, Methods, 1916, 109. 182 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 TABLE 3. Determination of gluten. DISTILLED WATER TENTATIVE METHOD* CONTAINING 0.1 PER DISTILLED WATER ANALYST CENT OF SODIUM CHLORID Wet Dry Wet Dry Wet Dry per cent per cent per cent per cent per cent per cent RM: Bohne se eee 29.07 10.67 29.53 10.43 22.60 8.93 29.13 10.87 30.40 10.73 23.33 8.80 Boat SaaS 29.13 10.77 24.00 9.27 G)DiGarby-r..ee | eeeoo! 10.13 31.01 10.58 21.88 8.44 27.35 10.12 31.01 10.50 22.35 8.75 K. J- Ostechout: <<... - 29.4 30.1 25.7 10.60 10.30 9.80 29.5 29.7 25.1 2 bee 10.40 9.50 * Assoc. Official Agr. Chemists, Methods, 1916, 189. TABLE 4. Determination of chlorin. ETHER EXTRACTION ANALYST GASOLINE EXTRACTION IN JOHNSON EXTRACTOR parts per million parts per million BG yAtkmson secs sce os totes Seer 100 RUNepein ot eat iee ee 105 105 81 105 KS Osterhoutss.00C oes eee ee ee 96 100 98 125 CONCLUSIONS. From these results the following conclusions may be drawn: Moisture-—The use of calcium oxid would seem to give results which are as good as those obtained by the official method. In most cases, a slightly larger amount of moisture was obtained by the calcium oxid method than by the official method, which would indicate that the calcium oxid in a vacuum desiccator absorbs practically all of the moisture. Gluten.—The results obtained would seem to indicate that distilled water containing 0.1 per cent of sodium chlorid gives approximately the same amount of gluten as ordinary Washington tap water. On the other hand, the use of distilled water alone causes a very large loss of gluten. Inasmuch as the tap water varies to a very large extent in 1920] SKINNER: REPORT ON SOFT DRINKS 183 different cities, it might be best to recommend that the washing of gluten should be done by the use of distilled water containing a certain proportion of sodium chlorid or other salts. Soluble carbohydrates —The results in this case would seem to indicate that the use of 1 per cent hydrochloric acid is to be preferred as a medium of extraction. Cold water extract—The results of these analyses would show that a 45 minute extraction at 10°C. gives practically the same results as the 45 minute extraction at 5°C.; 14 hours’ extraction at 10°C. gives con- siderably higher results. Therefore, it might be wise to advocate that the extraction be carried on at a temperature of from 5 to 10°C., instead of limiting it to 10°C. alone. Chlorin.—Three collaborators obtained quite concordant results in the determination of chlorin by the two methods. The results, there- fore, are very encouraging, but, inasmuch as these results are so few in number, it is recommended that this work be continued another year. Ash.—tThe results of the ash determination by the use of a minimum amount of calcium acetate are remarkably close to those obtained by the official method. If it is more convenient to use calcium acetate in the determination of ash in flour, it should be allowed in view of these results. RECOMMENDATION. It is recommended— That the work of this year be repeated. No report on wines was made by the referee. REPORT ON SOFT DRINKS. By W. W. SKINNER (Bureau of Chemistry, Washington, D. C.), Referee. The Referee on Soft Drinks, after correspondence with several per- sons who had signified a desire to participate in work of this character, decided that collaborative work was inadvisable until methods could be suggested with a reasonable prospect of satisfactory results being obtained. The referee is of the opinion that valuable time and energy may be wasted to no purpose in collaborative work on methods which have not as yet been subjected to a critical study and investigation by some one, expert in the particular line of work to which the methods apply. It seems to the referee that if collaborative work is to be main- tained on a sound basis, then collaborators should be expected merely to test the application of well-defined methods rather than to assume the role of investigator in the development of new methods. 184 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMIStTs [Vol. IV, No. 2 With this in mind, therefore, no collaborative work was planned. Work, however, was undertaken by one investigator under the direction of the referee, with the hope of developing quantitative methods for the determination of ginger and of capsicum in ginger ale and other ginger drinks. Many difficulities have been encountered in this work and while no satisfactory method has so far been developed, the pre- liminary work has yielded interesting information which has a direct bearing on the controversy regarding the use of capsicum in ginger ale. The referee is not in a position to report definitely on this matter, but can submit only a report of progress with the suggestion that the work be continued. ADDRESS BY THE HONORARY PRESIDENT. H. W. Wirtey (Good Housekeeping, Bureau of Foods, Sanitation and Health, Washington, D. C.). I think we are getting on in the world. I remember the earlier days when we used to meet at Cabin John Bridge, and all could get on one trolley car, and those, by the way, were very happy days, which I remember with great pleasure. Those were the days before I had turned prohibitionist, and it was not considered bad form to say “Prosit’’. That is one Latin word now that is taboo. Most people think it is German, but that is because they do not understand Latin. After the Cabin John Bridge days, we went first to a small hotel until we grad- uated, and for a long while we went to the Raleigh. Now we have come to the Willard. That is what we call “high life’. Now I promise you that, if this country ever has the great good fortune to make me President of the United States, I will invite you to meet in the White House. I know that very few of your members came to this town with the idea of insulting me. One of them did, but I am not going to name him. In the English Parliament to name a man is the highest disgrace that can be heaped upon him. I will tell you, however, what he said: “Have you written out and committed to memory your annual extemporaneous address to the Association of Official Agricultural Chemists?” Well, now, in one sense that was a compliment. When a man can stand up and make an extemporaneous address that has all the ear marks of the midnight oil, it shows the possibilities of the human intellect. Now you are going to get another one of that kind. If I remember, my last extemporaneous address was on the subject of colloidal chemistry, and I can only say that great progress has been made in the application of col- loidal chemistry in the experience of man, because, if ever things were 1920) WILEY: HONORARY PRESIDENT’S ADDRESS 185 mixed up more completely in the history of the world than now, I do not know when it was. We have nothing but colloids afloat in a sea of blood—itself a sea of colloids. I am not going to make another address on colloidal chemistry because I am sure I would not be able to equal the address I formerly made, but I do want to call attention to the condition of affairs to which this disorganized condition of the world has brought us, and it emphasizes what has always been known to be. and now is recognized by everybody to be the fundamental industry of the world—the industry of agriculture. This is the industry which you are aiming to promote, and it is one which today has supreme importance, more even than munitions and supplies of guns, more even than the man power of the world. The problem of agriculture looms up as the great predominant problem of today. Some of its aspects are not, perhaps, peculiarly chemical, and I am going to take the liberty this morning of disgressing somewhat from the path of chemistry, and call attention to some of the problems in agriculture which, although partly chemical, are not entirely so. First of all, the problem of feeding the world is a problem peculiarly agricultural, and also, to a considerable extent, a problem which is peculiarly chemical. The food problem today is paramount in import- ance as an agricultural problem, both from the point of production and the point of distribution, and the agricultural chemist has a great deal to do with both. The production of food, as we all know, is a strictly agricultural-chemical problem. Given the area, given the climate, the amount of food produced is a problem of scientific agricul- ture. The better the principles of scientific agriculture are understood and practised by the farmer, the greater will be the yield of his fields. other things remaining equal. That being the case, the production of the crop is largely a matter of cultivation and plant food. The war has cut us off from one of the essential ingredients of plant food, without which the ration of the plant is unbalanced, namely, potash. The problem is to supply, if possible from other sources, the potash which we formerly received from Germany. Of course, there are no deposits of potash which compare in extent and inexhaustibility to those which are within the confines of the German Empire, and yet there are sources of potash which, if they could be utilized, might supply our need. There is enough potash locked up in the feldspar of this country to supply the nations of the earth for an unnumbered series of years, if it could be unlocked, and chemists are working upon that problem. The deposits of potash which we already have are being exploited, as you know, and a considerable amount of potash is now available which a few years ago was untouched. Even the dust from cement and other factory chimneys is being saved for the potash it contains. The sea is to be 186 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 utilized as far as possible, and the kelp is being harvested to a somewhat considerable extent in furthering this purpose. We are getting some potash, but at a price the farmer can ill afford to pay, or perhaps can not pay at all at the present time. It therefore seems to me that the appli- cation of potash to our fields in any considerable quantity, representing the needs of the crop, is altogether a difficult problem at the present time. Now that has taught some of us a good lesson. Many have learned that the soil contains sufficient potash for the crop, and that is a good lesson to learn, for, when the old supply again becomes available, the farmer will have learned that some soils are sufficiently rich in potash, so that it is not altogether necessary to purchase additional quantities. It is hoped that to this extent the shortage of potash may prove a blessing in disguise. All other plant foods, as you know, have greatly increased in price. Take, for instance, the acid phosphate which is used as a basic fertilizer, and used more extensively than any other kind. This is a substance that helps unlock the imprisoned potash. The price has more than doubled since the war began. A few years ago, I was able to get acid phosphate by the carload at from nine dollars and fifty cents to ten dollars, laid down at my station, and now I pay twenty dollars, and perhaps I shall have to pay more before the war is over. This has led to the use of natural phosphate rock reduced to a fine powder; and, where the soil is inclined to be acid, that treatment apparently is giving very favorable results. I, myself, have tried it on my farm—TI have treated about forty or fifty acres of some acid soil with natural phos- phate rocks, and have had good results therefrom. But it does not do any good, or at least very little good, to put such a product on a soil which has been properly limed, and which is in a condition to bear leguminous crops. It is difficult to secure any visible good effect. In so far as nitrogenous fertilizers are concerned, the price has also gone up one hundred per cent or more, so that now fish scrap and tankage can not be purchased at a price which the farmer feels he is able to pay. There- fore, my experience is that all forms of plant food should be put on a strictly economic ration by the farmer. To this statement the reply is made that the farmer is receiving proportionately more for his crops and can pay the increased price without suffering any hardship. That is true in so far as it is applicable. If the farmer’s crop is one hundred per cent more profitable than it was before, he can pay one hundred per cent more than he did for his plant foods. If, on the other hand, his crop is not that much more valuable, then he is working at a loss. This is one of the great problems of agriculture today—the feeding of the crop. It is driving us again into a path which we may in the future follow as a matter of choice. To supply nitrogenous fertilizers on the 1920] WILEY: HONORARY PRESIDENT’S ADDRESS 187 farm, it is advisable to grow and plow under leguminous crops. That is being done to a very large extent in this country, and now, to a larger extent than before. The supply of nitric acid from the air, while promis- ing, is yet commercially infinitesimal. The price of lime has also greatly increased. I have just joined the large and increasing body of agricul- turists who are not using burned lime any more. The farmer who has a large amount of manure from his stables can not afford to use burned lime on his land, for if you have any experience you know how wasteful it is. It would be interesting to drive about in the country where freshly burned lime has been spread on stable manure and smell the ammonia in the air, as you can do at any time, even several days after the application. So we are growing beans and other leguminous crops, not only for the hay, but for the actual benefit which we get by ploughing the crop under. In this way we have been able, so far, to keep our crops almost, if not quite, up to normal. There has been very little shortage in the magnitude of the crop by reason of the increased cost of production. That part of the problem seems to have worked itself out most satifactorily. We come now to the most important problem of all, and that is man power. How are we to fill the place of our farmer soldiers? There are two ways of overcoming that difficulty. One is to secure a larger number of laborers, and the other is to go to work yourself. I think the best advice I can give is to go to work yourself. I am somewhat of a believer in Tolstoy’s theory, that it is a crime for any man to eat anything which he, by his own labor on his own farm, has not produced. If every one could be brought to that way of thinking, the scarcity of farm labor would be quickly overcome. I go right out into the field and work. and I feel sure that I have fulfilled Tolstoy’s theory. I believe that every bit of food which I and my family shall eat during the next year has been produced directly or indirectly by my own hands. I do not sit down to my table and feel that I am robbing any one. DEVOLUTION. Those who live in the city must move out. The great curse of this eountry is concentration in cities, and the great curse of our industries is not that they are industries, but that they are centered in cities. I am of the opinion that cities should not allow any productive industries, but should devote their energies to banking, transportation, and ex- change. They should distribute commodities or make them available, but when they make anything out of a raw material, and dig into the soil and make something out of it, that is wrong. Every time you send a shoe factory or a machine factory to an agricultural region, you benefit not only those who work in that factory, but the farmers round about. We must devolute our cities, and this you see going on all the time. 188 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS | Vol. IV, No. 2 Every one is going out to the country and getting a little place if he can. Do you realize that if you have one or two acres you can grow almost enough on it to supply your family? I know a banker in this city who has a half-acre of land, and he grows almost enough on that half-acre to supply his family with food. He can sell enough of the excess of the articles he raises to pay for the food he can not raise on his land. He understands how to get the most out of the soil. His wife does her own work in the house. These industrious people are doing a large part in the great struggle im which we are engaged. MAN POWER. Now as to man power. I remember James Whitcomb Riley’s story of the “Old Man and Jim’. That is one of the best stories I ever read and one of the most pathetic, for that matter. What I am going to call attention to is the worthlessness of Jim on the farm. While he never did anything on the farm, he was the old man’s pride. The other sons of the farmer were his right-hand men, but although “Jim was the wildest boy he had”’ the old man was “all wrapped up in Jim”. But when the war broke out—the contest between the States that is called the Civil War—Jim enlisted and made an ideal soldier, for “his fightin’ was good as his farmin’ bad’’. If a great many people I know in the country made as good soldiers as they make bad farmers, it would be a blessing to have a lot more of them drafted into the Army. As it happened in my part of the community, the worthless farmers were not selected, and those who were industrious and of some account were taken. I should like a selective draft. too. I should like to make all of the boys in the country who will not work go into the Army. Instead of hanging around the railroad station they learn discipline and industry. When I go to my little place in the country I see dozens of young men hanging around the station. I suppose they want to see me—lI do not know what else attracts them. I will give them the benefit of the doubt. I should like to see a selective draft applied in such a way that they would ask each farmer who are good workmen and who are not. In that way, they might select an army of men whose “‘fighting would be as good as their farming was bad”. Our man power is going to be utilized to a great extent on the field of battle, and I am one of those—I may be misguided—who believe that every single activity and power of this country should be put behind the President in this great war. I do not care whether I agree with his policies or not. That is of no consequence. He is our President, he is the representative, the supreme authority of this great nation, and the man—I do not care what his political creed is—who does not stand behind the President 1920] WILEY: HONORARY PRESIDENT’S ADDRESS 189 is not fit to be called a citizen of the United States. So I am asking no exemptions for the people in the country from military service—not a single one. MOBILIZATION OF THE WOMEN. But what are we going to do? First, we ourselves are going to work. Second, we must call upon the women of this country. They are ready to help. You know there are hundreds and hundreds of things that a woman can do even better than a man. I saw three women gathering apples in Virginia last October, and doing it just as well and better even than the men could do. We should not have had our apple crop gathered without the help of the women. Then there is another great branch of industrial agriculture where the women are better than the men, and that is the dairy industry. Three or four years ago I was in Duluth and wanted to see some of the dairies there. They took me to a dairy owned and operated entirely by women as being the star dairy of that vicinity. If we could release the men in the dairy industry today and replace them with women, we should come very near making up for all the losses we have so far experienced. There are dozens of things a woman can do on the farm. I saw a woman not long ago in the corn field. It was ensilage cutting time and she said to me, “Let me go out in the field and I will show you that I can cut ensilage as well as a man’. She took a cutting knife and went out into the field, where she took one row while the man took two, and she finished her row and kept up with him, and never flinched. That shows the spirit of the women who want to do something for the country. They are always good workers and would make good soldiers. No doubt some of them would fight mighty well. I know they can fight if necessary, but perhaps we will not want to organize a “battalion of death” as they did in Russia. If the pinch comes they can go into the trenches. They can fight for their country and they will do it if necessary. So we are not going, in my opinion, to let our crops fail for man power, for we can have woman power. JUSTICE TO WOMEN. It seems to me that the men of this country ought to be generous enough, when the women want to go with them to the polls, to give them the rights of citizenship in this country. What a glorious thing it would be if, as a war measure, just as Lincoln enfranchised the slaves at the time of the Civil War, our President would say to Congress: “Enfranchise the women of this country. They are giving all of their energies to this war—give them their independence and their rights as American citizens.” What a splendid hour it would be in this country, 190 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 what a blow to the terrorism and the autocracy of the German Empire if all our women were enrolled in this great army! So I say we are going to call upon the women in this great problem of food production, and we are not going to call upon them in vain. FOOD ADMINISTRATION. The next great point is distribution. First, plant food; second, man power; and third, distribution. That is one of the most important of the triumvirate. We are not going to solve the distribution problem in the old-fashioned way—that is evident. We thought perhaps that in this generation we had discovered the idea of directing the distribution of food. I discovered lately in reading from an old author, a man who wrote two thousand years ago, Lucius Apuleius, that the Food Ad- ministrator is no new thing. Lucius Apuleius wrote a book, “The Golden Ass’. Lucius was transformed into an ass. Some men are born asses, others have asininity thrust upon them, while still others acquire assdom. Lucius was metamorphosed into an ass, but before this meta- morphosis took place he traveled into Thessaly, where he met an old schoolmate of his who was evidently a man of very distinguished powers. He had a great retinue of servants, and Lucius was astonished to meet his old friend in such an imposing environment. But listen to Lucius: ** “Holy Moses’, said I. ‘Who is this I see? It surely beats the band to see you in this gorgeous uniform all spangled with decorations. And such a crowd of attendants! You must be the Mayor of this town, old friend Pythias’. He replied, ‘Not quite so bad as that. I am only the Food Administrator of this municipality. Is there anything in particular you would like to have for your supper?’ “Thanks awfully,’ I replied, ‘I have already bought fish’. When Pythias saw my basket (for they had no delivery system in this market) he took it and made a careful inspec- tion of its contents. ‘How much did you pay for these minnows?’ he asked. “The horrid fish profiteer’, I replied, “wanted a whole silver plunk for this bunch of flappers but finally he let me have them for two dimes’. Taking me by the hand, Pythias led me into the Central Market and said ‘Show me the scoundrel who cheated you so egregiously’. “That is he, crouching in the corner’, said I, pointing my finger at the mercenary wretch, who seemed to shrink up as soon as he saw the Food Adminis- trator looking at him. Pythias rushed up to the Shylock of the Billings- gate and gave him a good tongue lashing. ‘You food shark’, he said, ‘How dare you play such a shabby trick on this old chum of my college days? You must be trying to make a desert of this fair country by your exhorbitant prices. Your license is revoked. You shall never have another fish to sell if you take more than a nickel a pound. You'll know what a Food Administrator is before I get through with you’. With 1920] WILEY: HONORARY PRESIDENT’S ADDRESS 191 that, Pythias seized my basket of fish and poured them on the floor of the market and jumped on the measly minnows with all four feet. And Pythias patted himself on the back and said, ‘See how I conserve the food and punish the violators of my regulations’. So I, blinded by the mighty power and diligence of the Food Administrator, went my way minus both my money and my supper.” A great many people in this country, since the Food Administration took its place, seem to be in the same fix. It is not anything new—this regulating of the food supply—and so I say the distribution of our food supply is the crowning work of the agricultural problem. What do we do with it today? I do not want to be personal in this matter, but I must speak the truth. It has been a very unfortunate habit of mine to tell the truth even if it is not very popular. The American stomach is the biggest garbage can in the world. We throw into it unnecessarily a large amount of food, which would feed another hundred million people. Now there is no doubt of that fact. The first thing we have to do is to stop making our stomachs garbage cans, and we can do that by eating only those foods that are necessary to keep us well and strong. I am not an advocate of any method of regulating nutrition that diminishes the vitality of the human organism. I want our soldiers to be well fed, I want our citizens to be well fed, and we have plenty of food to do that if we do it wisely, and at the same time we can save immense quantities from the garbage cans of this country for the benefit of our allies, so that they also may be well nourished and able to fight their battles. Napoleon said, and as far as human wisdom is concerned I think he is the greatest man that ever lived, “Soldiers fight on their bellies’. He knew the value of the commissariat. When his soldiers had climbed to the top of the Alps he had stored cheese and bread and wine with the St. Bernard monks (the prohibition law had not gone into effect on the Alps) and every soldier as he reached the summit had an abundant supper. They felt that their commander was looking after their physical wants. And so, refreshed and enthusiastic, they de- scended to the plains of Lombardy and fought at Lodi and Marengo. We must realize that nutrition, and proper nutrition, is the basis of all our military success. Hence, I am heartily in sympathy with our Food Administration. I believe in the great principle of conservation of food by force and not by argument. There is no use in arguing with a man who has the means to sit down to a “‘square meal’. I do not want you to stop with mere argument in this food administration work. I want to see bread cards and meat cards and sugar cards, so that not even the Presi- dent may get more than his share. Let us make this food administra- tion work more effective by making it more urgent and less persuasive. I am perfectly willing to argue with you in times of peace as to what 192 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 you should eat and what you should drink and wear; I was once opposed to prohibition because I did not believe it was my business to say to you what you should guzzle. But now I believe we should say to you what you shall eat and what you shall drink in this time of stress. It is a necessity of war. I would not allow any one to buy food except in pro- portion to the number in the family. Then they have to divide it wisely. How much do we need? You know as much about that as I do. A man of your size and my size needs 3000 calories a day, and if he goes out into the field and earns a part of his food he may need 500 more. If he sits down and writes letters to you to persuade you not to eat anything he ought not to have more than 1800 or 2000 at most. I tell you if the Kaiser could only look in upon this country and see the number of typewriters at work he would slink away in terror. We are fighting this war by typewriters instead of by machine guns. The President hit it off beautifully in his Buffalo address when he said, “‘I am glad to get away from Washington where so many people know so many things that are not so”. One of the things that is not so is that you can win this war by writing on a typewriter. Every one of those people operating typewriting machines should be making shot and shell—they carry messages that can be understood by the Germans. I should like to see the battle cry of freedom engraved on a bayonet point and the Battle Hymn of the Republic engraved on a shell. Then the Germans would understand what we mean! THE NEED OF EFFICIENCY. Now my plea to the farmers of this country is for efficiency, to get all the plant food that you can, to get the man power and the woman power that you can, and you can get plenty of it if you will recognize woman’s ability. Women are human beings, and are entitled to the right to labor, just as much as they are to the right to vote and to fight. What we want to do is to put all of our energy into effective work and not into teaching and persuading. The time for that is past. When a German soldier has his bayonet against your breast that is no time to argue with him. I want to urge men and women to action. When this war broke out, I asked to serve in the Quartermaster’s Department. I did not care in what capacity—only to help in some way, as I believed I was capable of doing. What reply did I get? Something like this: “Dear Sir: Your application to serve in the Quartermaster’s Depart- ment has been received and placed on file. I call your attention to Regulation 18072 X which forbids the employment of any one in the Quartermaster’s Department who has passed the age of 65.” It was no fault of mine that I was over sixty-five years—I have entered my seventy-fourth year. I surely could do service of some kind for my 1920] WILEY: HONORARY PRESIDENT’S ADDRESS 193 country. Are we going to let regulations stand in the way of our fighting this great war? Let every man fight and help if he can for freedom and democracy. My friends, this is my extemporaneous address. If you think it has been written out and committed to memory, well and good. I think it is good enough to have been written out and committed to memory myself. I have been with you now for thirty-five years; you are my professional brethren. Some of you are older than I, at least in appear- ance, but | doubt if there is one here with a younger heart or with a more flexible artery than I have, who speak to you. I want you to have a strong heart and a flexible artery. Then you can serve your country, and your country now, more than ever before in its history, needs your help. The meeting adjourned at 12.30 p. m. to reconvene at 2 p. m. SECOND DAY. TUESDAY—AFTERNOON SESSION. REPORT ON DISTILLED LIQUORS. By J. I. Patmore (Bureau of Chemistry, Washington, D. C.), Referee. No report was made other than to mention an experiment undertaken to test a method for the preservation of aldehyde-free alcohol. This experiment will be continued over several years and a full account of it will be included in a subsequent report. No report on beers was made by the referee. No report on vinegars was made by the referee. No report on flavoring extracts was made by the referee. No report on meat and meat products was made by the referee. A NEW METHOD FOR THE ESTIMATION OF HISTIDIN. By. W. E. Torun and P. F. Trowsprince!? (Agricultural Experiment Station, Columbia, Mo.). The following experiments were made to determine whether or not bromin absorption determinations would be of value in conjunction with the Van Slyke analysis. Two 5 cc. aliquots (equivalent to 0.0323 gram of protein nitrogen) of the solution of the bases of a coagulable protein sample were treated with 10 cc. of bromate solution (equivalent to 18.71 cc. of thiosulphate) and 50 cc. of water, 10 cc. of bromid solu- tion, and 5 cc. of hydrochloric acid. Bromination was allowed to pro- ceed for 15 minutes. It took 17.0 cc. of thiosulphate (equivalent to 0.008465 gram of bromid) to titrate the excess of bromin. The bromin absorbed was 0.01477 gram. Deducting 0.00259 gram due to cystin (cystin nitrogen = 0.0009 gram found by determining sulphur in another aliquot), assuming that cystin consumes 10 atoms of bromin per molecule, there is a consumption of 0.0119 gram of bromin by the histidin in solution. One molecule of histidin absorbs 2 atoms of bromin accord- 1 Present address, Agricultural Experiment Station, Agricultural College, N. Dak. 2 Associate Referee on the Separation of Nitrogenous Compounds in Meat Products. 194 1920] KERR: REPORT ON EDIBLE FATS AND OILS 195 ing to Siegfried and Reppin!. Calculating from the above data, 9.68 per cent of histidin nitrogen is obtained. To this must be added 1.17 per cent as a correction for the solubility of histidin in the presence of phosphotungstic acid as determined by Van Slyke, making it 10.86 per cent of histidin nitrogen. This is somewhat higher than was obtained by the Van Slyke method, 9.08 per cent. By the same method another sample had an average of 4.73 per cent of histidin nitrogen; by the Van Slyke method, 4.97 per cent. The method gave also a value of 2.15 per cent of histidin nitrogen for another sample, while the Van Slyke method gave 1.90 per cent. The accuracy of this method may be considerably increased by using more dilute solutions for the titrations, so as to measure larger volumes. A factor for bromin absorption for histidin may be necessary, since histidin seems to absorb somewhat more than 2 atoms of bromin per molecule. Attention may be called to the fact that this method requires only two determinations of which the cystin nitrogen is very accurate, while the Van Slyke method requires three determinations. Amyl alcohol may interfere by absorbing bromin, but in the Van Slyke analysis the solution of the bases, after removal of the phosphotungstic acid, is evap- orated under a vacuum and boiled off. It is not known whether the purin and pyrimidin which are precipitated by phosphotungstic acid will absorb bromin under the conditions employed in these experiments. If further proof of the value of this method for the determination of histidin is obtained, a Van Slyke apparatus will no longer be necessary for a determination of the hexon bases. No report on meat extracts was made by the associate referee. REPORT ON EDIBLE FATS AND OILS? By R. H. Kerr (Bureau of Animal Industry, Washington, D.C.), Referee. The work consisted of a study of the modified method for the detec- tion of the adulteration of lard with fats containing tristearin. No samples were sent out for cooperative work but it was requested that each collaborator make his own mixtures using such fats as he believed to be used for the adulteration of lard, or for whose detection he con- sidered a method of detection desirable, and to examine them by the method to be studied. After completing his tests, he was requested to 1 Z. physiol. Chem., 1915, 95: 18. 2 Presented by H. S. Bailey. 196 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 send the sample mixtures to the referee, withholding the report of his results and the composition of the samples. Samples were submitted by three collaborators: P. Rudnick of Armour & Co.; J. J. Vollertsen of Morris & Co.; and C. H. Robinson, Central Experimental Farm, Ottawa, Canada. Mixtures were also made up in the Meat Inspection Labora- tory of the Bureau of Animal Industry, Washington, D. C., and tested by the referee and also by two other analysts, to whom the composition of the mixtures was unknown. COMPOSITION OF MIXTURES MADE BY THE REFEREE. Sample 1.—Pure lard + 3 per cent oleo stearin. Sample 2.—Pure lard + 3 per cent hydrogenated cottonseed oil. Sample 3.—Pure lard + 5 per cent hydrogenated lard. Sample 4.—Pure lard. Sample 5.—Pure lard + 5 per cent hydrogenated whale oil. Sample 6.—Pure lard + 5 per cent soft beef tallow. Sample 7.—Pure lard + 1 per cent hydrogenated cottonseed oil. Sample 8.—Pure lard + 10 per cent hydrogenated lard. Sample 9.—Pure lard + 10 per cent coconut oil. Sample 10.—Pure lard. Sample 11.—Pure lard. TABLE 1. Cooperative work on the determination of melting point on mixtures made by the referee. ANALYST AND SAMPLE NUMBER Uae “(B) DIFFERENCE | A+2(A—B) R. H. Kerr es t : ¢ Sample: Lisnencessce sq erence 62.8 59.4 3.4 69.6 Sample geese accep ermine be 62.4 62.0 0.4 63.2 Samplewarit cee ae ae: tare 63.6 59.0 4.6 72.8 Sample 40 yteti cia. cake ese 64.2 58.6 5.6 75.4 Sampleve bas strat cckoe he, Soe ee 61.2 58.4 2.8 66.8 Sample 60s soe oe ete eee 62.4 58.2 4.2 70.8 Sampleredimseec eee cca es ores 63.0 60.6 2.4 67.8 Sample: (8.5: Baha 2 SE te tee 62.8 59.6 3.2 69.2 RSET ra1 8) (cha 8s ta eye a Pe 64.2 58.8 5.4 75.0 Sample OAS 60a inwss toy Soke 64.4 58.8 5.6 75.6 Sampleviile po: eee See ees eee 64.2 58.8 5.4 75.0 R. M. Mehurin, Bureau of Animal In- dustry, Washington, D. C. Sample Lert e. . Pee ee creme 62.4 59.0 3.4 69.2 Sample inet 2s be ae eee 61.7 61.4 0.3 62.3 Sample 3). .c,c0sc eee eas ee 63.4 58.8 4.6 72.6 Sample 4000 ee etree sees cae 64.2 59.4 4.8 73.8 Sample (5. 4ase ere tae 61.0 57.8 32 67.4 Samples 6.915 81s .\.0 9 coe cero 63.2 59.6 3.6 70.4 Sample fee ccc eee ere eee oe 62.6 59.0 3.6 69.8 Samples'8 59; acne eee 62.4 59.2 3.2 68.8 Sampleyio he oa nara atone 64.1 59.8 4.3 72.7 Sample Mie... Ss cee one 64.0 59.8 4.2 72.4 ee 1920 KERR: REPORT ON EDIBLE FATS AND OILS 197 Tape 1.—Continued. ANALYST AND SAMPLE NUMBER aa AN “(B) DIFFERENCE | A+2 (A—B) oG; Gs °C. °C. E. H. Ingersoll*, Bureau of Animal In- dustry, Washington, D. C. Sample mse co oes Soe isc! eS 62.6 58.8 3.8 70.2 Sam plemaeanr ert. Mee ae ence heen te 62.8 61.2 1.6 66.0 Stay) (EEG Bearers eee or eae eee ieee 63.0 58.0 5.0 73.0 Stave} log WO ee ei Perel eee 64.2 57.8 6.4 77.0 SETroyg| ORS eee te eee eee Oe 60.6 56.2 4.4 69.4 BWIDIG WM Girne eto wiscists ain vel eines 62.4 58.8 3.6 69.6 SSRUNDIG me ose eaere cae ene cie seven one areas 62.6 59.4 3.2 69.0 \Sharvryo) [2 ks) ee a eae uy eae 62.5 59.0 3.5 69.5 Samples Qestencnkay. 6. SER. one’s 64.4 58.2 6.2 76.8 SS IPI eM ee espa bat cea Paras atermcarsk she vale 63.9 58.0 5.9 75.7 * Since deceased. COMPOSITION OF MIXTURES PREPARED BY P. RUDNICK. Sample 1.—Lard + 5 per cent completely hydrogenated cottonseed oil. Sample 2.—Pure lard. Sample 3.—Lard + 5 per cent hydrogenated soy bean oil. Sample 4.—Lard + 5 per cent hydrogenated corn oil. Sample 5.—Lard-+ 5 per cent soft oleo stock. Sample 6.—Pure lard. Sample 7.—Pure lard + 5 per cent hydrogenated corn oil. TABLE 2. Cooperative work on the determination of melting point on mixtures prepared by P. Rudnick. ANALYST AND SAMPLE NUMBER ore (AN oas “(B) DIFFERENCE | A+2 (A—B) P. Rudnick S ai a i Samplecli;,: gcse: enero 62.7 61.8 0.9 64.5 SHAH) 1] Ee eee is nn ee 63.9 o.5 6.4 76.7 StATTyO) 33a Ae een eeis ko ete oitee tote 63.6 50 6.1 75.8 Seererye) it coe a ene ae bn ee hear 63.5 62.7 0.8 65.1 SSRTELPLE LO oh oak Seal apa cece Me ee an ie 62.8 57.7 ll 73.0 Sample Giyccc 5. = oi«, see 63.3 57.2 6.1 75.5 IBM DLE Mics c san 3,86 diay een na eeres 62.2 60.9 1.3 64.8 R. H. Kerr Sh) dl ete ree socio cca 63.2 62.4 0.8 64.8 SSAITIDIEEZ ole =<) 2 crea 2 ate ern aye Terma 64.2 58.6 5.6 75.4 Sampletan js s.06s. satel: Hotere 63.4 58.0 5.4 74.2 Sinnnliéh See ae pence oe Saeeporiiee 64.6 63.0 1.6 67.8 ATTIC os otey create se ictche aye tems ahetada sais oravnic 63.4 58.8 4.6 72.6 AITO Ge Semen ast artse aia oo 64.2 58.6 5.6 75.4 Siri yn) G7 (epee eee ee ee eae See toa 62. 61.2 0.8 63.6 198 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 COMPOSITION OF SAMPLES PREPARED BY J. J. VOLLERTSEN. Sample 1.—Pure lard + 0.5 per cent vegetable stearin. Sample 2.—Pure lard + 1.0 per cent vegetable stearin. Sample 3.—Pure lard + 2.0 per cent vegetable stearin. Sample 4.—Pure lard + 0.5 per cent beef stearin. Sample 5.—Pure lard + 1.0 per cent beef stearin. Sample 6.—Pure lard + 2.0 per cent beef stearin. TABLE 3. Cooperative work on the determination of melting point on mixtures prepared by J. J. Vollerisen. ANALYST AND SAMPLE NUMBER SECA enee CB) DIFFERENCE | A+2 (A—B) C. Kumli, Morris & Co., Chicago, Ill. i a e a Sample soc fe eto a a cierto 61.5 57.0 4.5 70.5 Sample 2enteeicne: sg. ore «eee aes 60.8 57.8 3.0 66.8 Sample(3® 22-0 chine es eee 59.7 58.8 0.9 61.5 Sample:4: - 4h. SS aes Ses ete ae 62.6 57.9 4.7 72.0 Sampleip: 2: ace ean een oes eee os 61.8 56.6 Ge 72.2 Sam pleiGyes ces Hest seer 60.8 55.8 5.0 70.8 R. H. Kerr Sample slic ois. ser eae cetera 63.0 58.8 4.2 71.4 Sample.24-o= 28s eee eee 62.2 59.6 2.6 67.4 Samplei3eo. crise oe ee ene 63.2 61.8 1.4 66.0 Sample 40000 2. F275 See 63.4 58.6 4.8 73.0 Samples ee fee oe ee ee 62.8 57.6 5.2 73.2 Sam ple\ Go cscveeccseess erg en 62.0 57.8 4.2 70.4 COMPOSITION OF SAMPLES PREPARED BY C. H. ROBINSON. Sample 1—Lard + 1 per cent hydrogenated soy bean oil. Sample 2.—Lard + 2 per cent hydrogenated soy bean oil. Sample 3.—Lard + 3 per cent hydrogenated soy bean oil. Sample 4.—Lard + 4 per cent hydrogenated soy bean oil. Sample 1—Lard + 1 per cent hydrogenated cottonseed oil. Sample 2.—Lard + 2 per cent hydrogenated cottonseed oil. Sample 3.—Lard + 3 per cent hydrogenated cottonseed oil. Sample 4.—Lard + 4 per cent hydrogenated cottonseed oil. Sample 5.—Lard + 5 per cent hydrogenated cottonseed oil. Sample 1.—Lard + 1 per cent hydrogenated vegetable stearin. Sample 2.—Lard + 2 per cent hydrogenated vegetable stearin. Sample 3.—Lard + 3 per cent hydrogenated vegetable stearin. Sample 4.—Lard + 4 per cent hydrogenated vegetable stearin. i, 1920) KERR: REPORT ON EDIBLE FATS AND OILS 199 TABLE 4. Cooperative work on the determination of melting point on miztures prepared by C. H. Robinson. ANALYST AND SAMPLE NUMBER SUR ice “7B) DIFFERENCE | A+2 (A—B) C. H. Robinson ee & c = LUC se oar ons eats tr eee RO Ke EEE 63.6 57.3 6.3 76.2 Samplevlere. £ oe accross hens oseas eats 63.2 60.1 Sill 69.4 Sampler 2 es accede tore caste cas shoes oye 62.5 60.5 2.0 66.5 Sampler ree hier ea tes Mee 63.1 61.0 2.1 67.3 Sample ase: eee a acca ese 62.5 61.1 1.4 65.3 Samplewlly Seisteeactic aes os wines ee vie 62.9 57.9 5.0 72.9 ISAM DILEL 2 Meccan eases eee PS ee 62.8 59.2 3.6 70.0 SHVin}s) OC RAeiAn GOO ere Ee ae mae 62.3 58.7 3.6 69.5 Sam plerd-reycianincctcays oo Geeianc cs 62.1 59.2 2.9 67.9 Sampleseccn te: tc monn sro sn coe ee 62.5 59.8 2.7 67.9 Samplevleee soe oo se cre senae eon 63.2 59.8 3.4 70.0 SAID LEED ey pa ete ts ciples chavo oelinee 62.5 60.5 2.0 66.5 Samplers acre pei Miicsoer ic 62.4 60.7 ie2/ 65.8 Sanmple diate (ns mhet 3. ssc stae amie 63.4 62.1 1.3 66.0 R. H. Kerr ample lie secs oe sce actors cioisksl sete 63.0 59.8 3.2 69.4 Sample2eoe een eee ee 62.2 60.4 1.8 65.8 Sample:duecnee nr Anis ee eee 62.4 61.2 12 64.8 Sample:deer terns Pere eee 62.6 61.2 1.4 65.4 Samples aise capictert:< vite arctan 62.8 59.0 3.8 70.4 re titie fo} Ley SAE eee SE Re eens ee 62.4 59.6 2.8 68.0 Sanipleroee eter. ee 62.0 59.8 2.2 66.4 Sample Aen dies thao de nen Lee 62.2 60.6 1.6 65.4 Sample: Sentence ast the are Poaeis 62.6 59.8 2.8 68.2 Samplenien. see eee se ole chews 62.8 59.8 3.0 68.8 Sample Disa. ce ete ara. yer eee 62.6 61.0 1.6 65.8 SINT OS es SS eRE ee ceenee Ome 63.0 61.4 1.6 66.2 Sampler eee seh vee coals s wicete 65.0 62.4 2.6 70.2 TABLE 5. Determination of melting point on lards known to be pure. SAMPLE NUMBER PTT ACB) DIFFERENCE A+ 2(A — B) SG: °C. °C. °G: 9347 64.4 59.8 4.6 73.6 9405 64.6 58.8 5.8 76.2 9406 64.4 59.4 5.0 74.4 9415 64.4 59.0 5.4 75.2 9322 63.4 57.0 6.4 76.2 9436 63.8 57.8 6.0 75.8 9577 64.0 57.4 6.6 77.2 9594 63.6 57.6 6.0 75.6 9550 63.6 57.6 6.0 75.6 9553 63.6 57.6 6.0 75.6 200 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 Tasie 5.—Continued. SAMPLE NUMBER | Sr CAN EE “B) DIFFERENCE A+2 (A—B) °e! °G eG: °€: 9570 63.6 57.6 6.0 75.6 9674 63.6 57.6 6.0 75.6 9675 63.6 57.6 6.0 75.6 9687 63.8 57.6 6.2 76.2 9697 §3.8 58.2 5.6 75.0 9747 64.0 58.2 5.8 75.6 10025 64.0 57.8 6.2 76.4 10028 64.0 58.4 5.6 75.2 10187 64.2 59.0 52 74.6 2135 63.4 57.8 5.6 74.6 10536 63.6 56.8 6.8 Uden 10537 63.4 57.2 6.2 75.8 10538 63.4 57.2 6.2 75.8 10543 64.0 57.6 6.4 76.8 TABLE 6. Determination of melting point on a series of mixtures containing graded proportions of oleo stearin added to the same lard. Sat ADULTERANT sig RANT SP “B) DIFFERENCE | A+2 (A—B) °C. °C. °c. eG. 1 INGNG. fst hat soca mctycre tons 64.4 57.6 6.8 78.0 2 0.5 per cent oleo stearin...... 64.0 58.4 5.6 75.2 3 1 per cent oleo stearin........ 63.6 58.6 5.0 73.6 4 2 per cent oleo stearin........ 63.0 59.0 4.0 71.0 5 3 per cent oleo stearin........ 62.4 59.0 3.4 69.2 6 5 per cent oleo stearin........ 62.2 59.4 2.8 67.8 U 5 per cent ox marrowfat...... 63.4 58.4 5.0 73.4 The results given above show clearly that the figure 71 for the sum A +2 (A-B) is too low to provide against quite material adulterations. The examination of the samples of pure lard shows that this figure may be increased to 73 without danger of condemning pure lard. It is rec- ommended therefore that the method be adopted as a tentative method in the following form: METHOD FOR THE DETECTION OF ADULTERATION OF LARD WITH FATS CONTAINING TRISTEARIN. Weigh out 5 grams of the filtered fat into a glass-stoppered cylinder graduated to 25 cc., add warm acetone until the 25 cc. mark is reached. Shake the cylinder until the contents are thoroughly mixed; then allow the cylinder and its contents to stand in a suitable place in which a temperature of 30°C. is maintained. After 18 hours, remove the cylinder and carefully decant the supernatant acetone solution from the crystallized glycerides, which are usually found in a firm mass at the bottom of the cylinder. Then 1920] HORTVET: REPORT ON DAIRY PRODUCTS 201 add warm acetone in three portions of 5 cc. each from a small wash bottle, care being taken not to break up the deposit while washing and decanting the first two portions. Actively agitate the third portion in the cylinder and, by a quick movement, transfer with the crystals to a small filter paper. Wash the crystals with five successive small portions of the warm acetone by means of the wash bottle and remove by suction the excess acetone. Transfer the paper with its contents to a suitable place, where it should be spread out, and any large lumps of the glycerides broken up by gentle pressure. When dry, thoroughly comminute the mass and determine the melting point of the crys- tals'. A melting point below 63.0 is regarded as evidence of adulteration, and a melting point below 63.4 is regarded as suspicious. After the melting point of the crystallized glycerides has been determined, transfer them to a 50 cc. beaker, add 25 cc. of approximately N /2 alcoholic potassium hydroxid and heat on the steam bath until saponification is complete. Pour the solution into a separatory funnel containing 200 cc. of distilled water, acidify, add 75 cc. of ether and shake. Draw off the acid layer and wash at least three times with distilled water. Transfer the ether solution to a clean, dry 50 cc. beaker, drive off the ether on the steam bath and finally dry the acids at 100°C. After the acids have stood for at least 2 hours after drying, determine the melting point in the same manner in which the melting point of the crystals was determined. If the melting point of the glycerides plus twice the difference between the melting point of the glycerides and the melting point of the fatty acids is less than 73°C., the lard is regarded as adulterated. REPORT ON DAIRY PRODUCTS. By Jutrus Hortvet (State Dairy and Food Commission, St. Paul, Minn.), Referee. The work included: (1) A further study of modifications of the official Roese-Gottlieb method applied to malted milk, dried milk and plain ice cream. (2) A further study of the Harding-Parkin method for fat deter- minationsin comparison with the present official and provisional methods. (3) A further study of the tentative Schmidt-Bondzynski modified method for the determination of fat in cheese. In accordance with the plan of work above outlined, the instructions sent out to the collaborators included full descriptions of the methods, following in the main the original published authors’ texts or the texts as found in the last compilation of tentative and official methods of analysis?. No material changes were incorporated and such additional directions as seemed to be required were given in separate paragraphs. Directions were given regarding the preparation, weighing, and pre- liminary treatment of samples. Much attention has been given by the referee to these preliminary details and experience has led to the con- clusion that no uniform rule of procedure can be Jaid down which will be suitable for all classes of dairy products. Before the application of 1U.S. Bur. Animal Ind. Cire. 132: (1908). 2 Assoc. Official Agr. Chemists, Methods, 1916, 287. 202 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 the regular analytical method, therefore, it has been found necessary to subject each given sample to such mode of preliminary treatment as has been shown by experience to yield most reliable results. The collaborators were also given general instructions relative to the follow- ing topics: (a) the condition of the sample as to fitness for analysis; (b) the various comparative tests to be made on each sample submitted; (c) the number of determinations to be made in duplicate and the averages to be reported; (d) the importance of experience and preliminary trials of the various methods before attempting determinations for the pur- poses of collaborative work. In the 1916 report of the referee', con- siderable attention was given to a discussion of the acid extraction modification of the official Roese-Gottlieb procedure, and it was then recommended that this modification be given further study. Accord- ingly, the plan of work has been so arranged as to secure from the collaborators comparative results showing the relative merits of the two procedures which have been somewhat in controversy for many years. Whatever may be the relative theoretical advantages of either mode of treatment of material before proceeding with the extractions, the aim has been at least to obtain practical comparative results under as favorable uniform conditions as possible by as many analysts as could be engaged to assist in the work. The referee is indebted to W. D. Strack, Chief Chemist for Borden’s Condensed Milk Company, New York, N. Y., for obtaining uniform sets of samples and forwarding them direct to the collaborators. Each set of samples included: (1) a plain ice cream, preserved with 15 grains of mercuric chlorid, in a tightly covered glass container; (2) a dried skimmed milk enclosed in a pasteboard carton; (3) a malted milk powder in a well-sealed bottle. In the study of the modified Schmidt-Bondzynski method, each collaborator was provided with a sample of Parmesan, a type of Italian cheese made from partly skimmed milk. Also, several weeks later, uniform samples of an American Pineapple cheese were distributed, and, although this type of cheese is essentially a Cheddar cheese made from whole milk, there was little difficulty experienced in preparing uniform samples and getting them to the collaborators in condition satisfactory for analysis. The collaborators were directed to carry out the work described in the following instructions: 1 J. Assoc. Official Agr. Chemists, 1920, 3: 436. 1920) HORTVET: REPORT ON DAIRY PRODUCTS 203 PREPARATION OF SAMPLES. DRIED MILK AND MALTED MILK. Thoroughly mix the entire sample before weighing a portion for analysis. Weigh out a 1 gram sample and transfer to the Rohrig tube with the help of a camel's hair brush and glazed paper. The mixing and weighing should be done as rapidly as possible for the reason that these powders very readily take up moisture from the air. (a) Alkaline method.—Add 10 cc. of water to the sample in the Rohrig tube, place the tube in a water bath at 60°C. and mix the contents by frequent shaking until no lumps remain. Add 2 ce. of concentrated ammonium hydroxid, mix thoroughly, heat again in the water bath at 60°C.. and proceed as directed in the official Roese-Gottlieb method. (b) Acid method—Heat the sample with 10 cc. of hydrochloric acid (sp. gr. 1.125) in the Rohrig tube, by means of a water bath at 80°C. for 15-25 minutes, being certain that the curd is well dissolved. Cool, add 10 cc. of alcohol, and proceed as in the official Roese-Gottlieb method. ICE CREAM. Allow the sample to soften at room temperature. Stir thoroughly with a spoon or mix by pouring from one beaker to another. Another good method of obtaining a uniform sample is to mix with an egg beater just before weighing. Owing to the fact that melted butter fat readily separates out and tends to rise to the surface, it is not advisable to soften the ice cream by heating on a water bath or over a flame. Weigh out 4 grams of the sample in a small dry beaker, add 3 cc. of water, thoroughly mix with a glass rod, and pour into the Rohrig tube, washing out the remaining portion with 3 cc. of water. Add 2 cc. of concentrated ammonium hydroxid, mix thoroughly, heat in a water bath at 60°C., and proceed as directed in the official Roese-Gottlieb method. The method of weighing may be simplified by pouring the mixed sample into a 25 cc. graduated cylinder. Weigh the cylinder, pour about the right amount into a tube, weigh, and determine the amount of the sample by difference. CHEESE. By means of a cheese sampler, draw three plugs, one from the center, one from a point near the outer edge, and one from a point between the other two. Reject the rind and grind the plugs in a sausage machine or cut them very finely and mix thoroughly. Proceed as directed in the Schmidt-Bondzynski method. DESCRIPTION OF METHODS. ROESE-GOTTLIEB METHOD.—OFFICIAL!. Notes on the method—If an emulsion occurs in the Rohrig tube, the addition of a little alcohol, followed by shaking, will usually break it up. Also, the use of a tube haying a larger caliber will tend to overcome this difficulty. If a Rohrig tube is not available, prepare an apparatus consisting of a large test tube provided with a blow-off device, as used in the Werner-Schmidt method. Care should be taken to make the final weighing of the ether-freed residue of fat under exactly the same conditions as those under which the dish was first weighed. 1 Assoc. Official Agr. Chemists, Methods, 1916, 289. 204 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 HARDING-PARKIN METHOD!. In applying the method to malted milk, weigh out a 1 gram sample, transfer to a Werner-Schmidt extraction tube, add 8 cc. of acetic acid (25% by volume) and warm the contents of the tube to about 50°C. in a water bath. When the protein has dissolved, add 12.5 cc. of redistilled carbon tetrachlorid and shake the tube vigorously for 2 minutes, then add 25 cc. of 95% alcohol and shake thoroughly; add 25 cc. of petroleum ether, shaking vigorously for 2 minutes, and an additional 15 cc. of the same ether. and continue shaking 1 minute longer. Close the tube and let stand until separated. Insert the blow-off device and blow out the ether layer cautiously through a filter into a weighing flask, taking care that none of the carbon tetrachlorid is blown off. Place 5 ec. of petroleum ether in a small evaporating dish and gently draw into the tube by suction applied to the blow-off device. After the ether has mixed with the layer in the jar, blow off and filter as before. Add 5 ce. of carbon tetrachlorid to the contents of the jar, thoroughly shake, then add 30 cc. of petroleum ether with repeated thorough shaking. Let stand and allow time to separate and wash once, as in the first blow-off. Repeat the above operation, using 5 cc. of carbon tetrachlorid and 30 cc. of petroleum ether, wash the filter paper with small portions of petroleum ether, evaporate off the ether slowly and heat the flask in an oven at a temperature of 100°C. and weigh. In applying the method to ice cream, weigh out a 5 gram sample. Add 5 ce. of acetic acid, 12 ce. of carbon tetrachlorid, 20 cc. of alcohol and 30 cc. of petroleum ether, and proceed as directed above. SCHMIDT-BONDZNSKI METHOD, MODIFIED?. GENERAL INSTRUCTIONS. Condition of samples——Carefully note the condition of each sample. The ice cream should not be separated or fermented, should be perfectly smooth, containing no small lumps of fat or curded matter. The cheese should not show evidence of having been overheated or of separation of melted fat. Comparative tests —On the sample of dried milk, make the official Roese-Gottlieb de- termination, both after the regular alkaline method of preparation and after the acid method of preparation, as directed under ‘‘Preparation of Samples’. On the sample of malted milk, make the same determinations as on the sample of dried milk and also make the determination by the Harding-Parkin method. On the sample of ice cream, make the official Roese-Gottlieb determination and also make the determination by the Harding-Parkin method. On the sample of cheese, make the determination by the Schmidt-Bondzynski method, modified. Duplicate determinalions.—In all cases, so far as possible, make two or more deter- minations by each method on all samples as directed. Report the individual results so obtained and calculate the averages of results which are in reasonable agreement. Experience.—In the case of all methods make preliminary trials. Repeat as many times as seems necessary in order to become adequately prepared for the regular de- terminations to be made on selected samples. The importance of ample experience can not be overestimated, especially in connection with the Roese-Gottlieb method and the Harding-Parkin method. Supplementing the foregoing instructions, at a later date, the collabora- tors were directed to make moisture determinations on all samples, except the sample of ice cream, according to methods of the association 1 J. Ind. Eng. Chem., 1913, 5: 131. 2 Assoc. Official Agr. C Themists, Methods, 1916, 297. 1920] HORTVET: REPORT ON DAIRY PRODUCTS 205 for dairy products'. It was also directed that the results obtained by the fat determinations be reported on the dry basis, as well as on the original whole samples. It so happens, however, that no special method is given for malted milk and milk powders. A general method is described? which is applicable to milk and condensed milk products and there is also given the tentative method for cheese*. A special effort was made to distribute uniform samples of each kind of product among the collaborators. There was no difficulty in the case of the malted milk for the reason that the sampling was made from the same uniformly mixed batch and immediately put up in well-sealed containers. The dried milk samples were similarly made up, although they were enclosed in pasteboard cartons which, in several instances, reached the collaborators in a somewhat damaged condition. However, even in this case there was no evidence reported of serious change in composition, and the material was promptly placed in stoppered bottles when received. The plain ice cream was thoroughly worked up to uni- form consistency before being placed in tightly covered glass jars, and each sample was furthermore preserved with a small quantity of corrosive sublimate. The samples of Parmesan and American Pineapple cheese were prepared in a satisfactory, uniform condition and great care was taken to put them up in suitable containers so that they might reach the collaborators without change or deterioration. Practically no serious complaints were received regarding the condition of the samples. Owing to the wide discrepancies shown among the moisture determina- tions on all kinds of samples, it has been decided to omit the results expressed on the dry basis. There are no circumstances to justify the belief that these differences could be due to actual variations in moisture content. For example, the results obtained on the malted milk show wide variations of from approximately 3.5 to 4.75 per cent. Similar results are noted among the other samples, particularly in the case of the Parmesan cheese. The method adopted for preparing and bottling the cheese samples was sufficient to assure the referee that no wide variations ought to be shown in the moisture results obtained by the various collaborators. The same statements can not be made with equal confidence regarding the samples of dried milk owing to the nature of the containers in which they were forwarded. Nevertheless, a careful inspection of the results for butter fat does not lead to any clue consistent with the wide variations reported among the results for moisture. These results vary from a trifle below 3.0 to somewhat over 7.5 per cent. This feature of the work has really no essential relation 1 Assoc. Official Agr. Chemists, Methods, 1916, 293, 296. 2 Tbid., 293, 33. 3 Ibid., 296, 53. 206 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 to the plan of study adopted for the present year and was simply thrown in as an afterthought. Nevertheless, it is worth while calling attention to the fact that the methods for determining moisture on certain classes of dairy products are not in very satisfactory shape. An inspection of the tables simply indicates that there is here an opportunity for profit- able study during the coming year. There is no moisture method adapted to such products as malted milk and dried milk, and some questions have been raised regarding the method for cheese!. TABLE 1. Moisture determinations. CHEESE MALTED MILK DRIED MILK Parmesan Pineapple per cent per cent per cent per cent 3.55 5.76 10.25 23.71 4.78 2.88 10.15 24.18 3.90 4.75 10.45 23.68 4.11 6.91 10.10 24.02 3.71 7.65 10.15 24.21 3.76 7.52 9.88 24.58 3.58 5.66 9.07 23.16 3.89 6.41 10.65 24.02 3.40 6.60 9.94 24.09 3.77 sax 10.31 wissoe 3.78 sole 10.23 Maximum 4.78 7.65 10.65 24.58 Minimum 3.40 2.88 9.07 23.16 A few comments on this subject have been submitted by collabor- ators as follows: In the moisture determinations, it was found impossible to obtain constant weight upon the dried and malted milk samples by drying in the water bath. Moisture was determined by drying in a vacuum oven at 95°C. to constant weight. There was appar- ently no oxidation or darkening under these conditions. The time required was approxi- mately 2 hours. In determining moisture on the Parmesan cheese, the weight was found to gain after 43 hours’ heating. In the case of Pineapple cheese, the weight gained after 7} hours’ heating. The final weighing was made at the expiration of 9 hours. In determining moisture on cheese, about 1 gram of material was weighed into a dish with a glass rod, 2 cc. of water added and the sample thoroughly mixed. The moisture was quickly evaporated on a hot plate at 180°C.; then the dish was placed in a vacuum oyen at a temperature of 100°C. for 20 minutes. Heating was continued at 20 minute intervals to constant weight. Some difficulty was experienced in determining moisture on the Parmesan cheese. 1 Assoc. Official Agr. Chemists, Methods, 1916, 296, 53. 1920] HORTVET: REPORT ON DAIRY PRODUCTS 207 The results obtained by the various methods for the determination of fat have been compiled and arranged for purposes of comparison in Table 2. TABLE 2. Fat determinations on dairy products. MALTED MILK DRIED MILK ICE CREAM CHEESE Par- Pine- z z mesan | apple = = ANALYST a3 as a= as 23 2 a = a oa | o= | £2 | og | c= | 62 | of | 358 | s82 g2 | $2 | se | $43 | $3 | $2 | SE | ess | 33s oa°| $2 | ae | Sa} ea | 82 | se | sme | eas fa q = a = -= x 2) Nn per cent| per cent| per cent) per cent) per cent| per cent| per cent| per cent| per cent M. L. Jones, Sears, | 9.00 | 9.26 | 8.88 | 1.07 | 1.10 | 7.69 | 7.75 | 23.07 Roebuck & Co., Chi- | 8.98 | 9.26 | 8.84 | 1.07 | 1.12 | 7.69 | 7.81 | 23.04 cago, Ill. 9.00 | 9.28 | 8.85 | 1.05 | 1.11] .... Hl Lael |chcsos IAVEFAge=. 5.2 je. es 8.99 | 9.27 | 8.86 | 1.06 | 1.11 | 7.69 | 7.78 | 23.06 E. C. Thompson, Bor- | 8.99 | 9.02 | 9.02 | 1.10 | 1.02 | 7.74 | 7.78 | 22.05 |36.02* den’s Condensed | 9.00 | 9.04 | 9.04 | 1.10 | 1.07 | 7.75 | 7.81 | 22.20 |35.89* Milki@o: New York, | 9:01 | 9:00) } 235-4] 1.12.) 1.05.) ‘7.75. | 7.84 |-...- |) --.- INDY. IAVETABES 2 5.5 5.22/52 9.00 | 9.02 | 9.03 | 1.11 | 1.05 | 7.75 | 7.81 | 22.13 H. E. Otting and E. E. | 9.07 | 9.16 | 8.99 | 1.19 | 1.02 | 7.93 | 7.83 | 22.85 |38.96* Dysart, The John | 9.12 | 9.16 | 8.99 | 1.24 | 1.07 | 7.93 | 7.81 | 22.82 |39.52 Wildi Evaporated | 9.16*| 9.13 | 9.02 | 1.24 | 1.03 | 7.93 | 7.82 | 23.03 |39.46 Milk Co., Columbus, | 9.07 | 9.13 | 9.00 | 1.16 | 1.13 | 7.92 | 7.80 | .... |39.03* Ohio. Det OP LOO: O08. ss cee We Gee nce 39.88* Pict rll Went 7.90 39.55 IAN ETARES ob. 9.09 | 9.15 | 9.00 | 1.21 | 1.06 | 7.92 | 7.82 | 22.90 |39.51 Raymond Hertwig, U. | 8.94 | 9.40 | 8.89 | 0.99 | 1.11 23.13 | 39.63 S. Food and Drug | 8.97 | 9.42 | 8.94 | 1.03 | 1.15 23.31 | 39.77 Inspection Station, | ....| .... | 8.98] .... aot 2 rere (ic eae U. S._ Appraiser’s Stores, San Francis- co, Calif. IAVETER Cs giiac ic 3 52: 8.96 | 9.41 | 8.94 | 1.01 | 1.13 23.22 | 39.70 E. W. Thornton, State | 8.99 | 9.34 | 9.50 | 1.31 | 1.56 | 7.90 | 7.73 | 22.57 | 38.67 Department of Agri- | 8.94 | 9.51 | 9.52 | 1.23 | 1.50 | 7.93 | 7.74 | 22.58 | 38.86 culture, Raleigh, | 8.92 | 9.52 Sea LeZO MICS S vedo Be eee ee INAG. 8.98 1.21 | 1.54 | 7.99 22200) eee Ae Be AGA 645 Bic eve Be | flea bey fret 8) Pan oe leans IAVERAG CS Sk S553 8.96 | 9.46 | 9.51 | 1:24 | 1.56 | 7.87 | 7.74 | 22.53 | 38.77 * Not included in calculations. 208 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 Taste 2.—Continued. MALTED MILK DRIED MILK ICE CREAM CHEESE Par- | Pine- =) z mesan | apple ANALYST s zz =| = = =| 3 335 = © Sons = a z 82 | S= | S3 | 82 | S | SB | 22 | 283) 282 be | $3 | se | $3 | $3 | $2 | SB | B82] G85 82 | 82 | §= | 82 | 82 | 8S | ES | Bae | dae e ee es a ee A es D L percent) per cent) per cent) per cent) per cent| per cenl| per cent| per cent) per cent Miss Kathryn Holden, | .... | .... | .... | 0-926] 0.927] 7.86 | 7.89 |22.59 |39.74 Hires Condensed |....|.... | .... | 0.956) 0.901] 7.85 | 7.86 |22.65 |39.83 Milk” Co.,; Philadele |) 2.24| «2275 4|| soshen|, O!980) ee mal e845 ccc || een ota phia, Pa. IAVOra Ze oysters: afore d|le-teyee Iineteine || 0:96; IN O:90 ie Soul @ Seal 22-020 | Soeur J. H. Bornmann, U.S. | 8.98 | 9.17 |8.74 | 0.89*) 1.01 | 7.69 | 7.35*|22.75*|39.42 Food and Drug In- | 8.82 | 9.23 |8.84 | 0.89*| 1.00 | 7.63 | 7.44*|23.30 |39.35 spection Station, . |23.26 Transportation | Building, Chicago, Ill. . Average: ec ..0-. 8.90 | 9.20 |8.79 | .... | 1.01 | 7.66 | .... |23.28 |39.39 . William Brinsmaid, | 7.39*| 7.78*|6.43* | 1.31 | 1.51] .... | .... |19.58*/386.55* Division of Foods | 7.39*| 6.87*/7.11* | 1.26 | 1.52] .... | .... |20.15*36.12* and Dairies, State Department of Agri- culture, Chicago, III. Average. ......... fewteetll aedee |) asSet e290 |) G2] 4. alll eee ee , J. T. Keister, Bureau | 9.028] 9.480/8.990 | 1.107} 1.256} 7.856] 7.848]22.92 |39.76 ’ of Chemistry, Wash- | 9.133] 9.375)9.934*| 1.150) 1.293) 7.837| 7.780/22.96 |39.75 ington, D. C. 9.017} 9.453/8.966 | 1.189} 1.276] .... | 7.890)23.12 |39.62* 8.910} 9.540)9.075 | 1.146) .... | ....-] 7.752) .... 189.755 Poets 9.560) teil biae ae 7.820 39.76 AV Grape fa oe aide 9.022} 9.482/9.010 | 1.15 | 1.28 | 7.85 | 7.82 |23.00 |39.76 Hugo Ringstrom, State | 9.20*/ 9.10 | .... | .... | .... | .... | .... |22.96 [89.30 Dairy and! Food) De= || 9:14.) 8:98) 322.5 || d25s0|_a. ce all ace | eee eae eo partment, St. Paul; | 9/05 | 91027) 32.5] Jnce |) one | oe ol een eezedizcn eee Minn. INV CLARE serys eae £201 0) lak? 3 ee lies SPR Meseereoel lene ocean gerocipetses [BURST Walter Egge, State | .... | 8.86 |9.05 22.61 Dairy and Food De- | .... | 9.03 |8.90 ace chill «oS Ih reece WES een 228 partment, St. Paul, | .... | 8.96 |9.01 eho Seal oss titel leans eerepall Mecca pee On Minn. .... | 8.96 |9.03 wa tahlh he Beball! tensch di fore mleiy | een 8.93 |8.92 8.97 AV erapeisoce nicee sei |s8:95018:98 Scie oeicnn rciciee eriaoise| eee Maxamom pees eee 9.10 | 9.48 |9.51 1.29 | 1.56 | 7.92 | 7.88 |23.28 |39.76 Minimum..........| 8.90 | 8.95 |8.79 | 0.96 | 0.91 | 7.66 | 7.74 |22.13 |38.77 Differences......... 0.20 | 0.53 |0.72 0.33 | 0.65 | 0.26 | 0.14 | 1.15 | 0.99 * Not included in calculations. 1920] HORTVET: REPORT ON DAIRY PRODUCTS 209 It was intended to include among the reported results only such figures as were believed by the analysts to be obtained by a proper procedure and concerning which there could be no assignable reason for doubt. It was, furthermore, contemplated that these averages would represent fairly the results obtained upon the various samples. In computing these averages, attention has been given to the customary rule of discarding values which are not in reasonable agreement. If two results have been found to agree within reasonable limits, it has been considered fair to report the mean of those results. If more than two results have been obtained by repeated determinations, only such values as agree within reasonable limits have been used in computing the averages. The comparisons are therefore made strictly among the averages, although it is interesting to note the variations which exist among the large number of individual determinations. In the case of the uniform samples of malted milk, the smallest variation between maximum and minimum results is found in the column headed “‘Roese- Gottlieb Alkaline Method’. The acid method, on the other hand, fails to yield results which are in equally satisfactory agreement. The maxi- mum and minimum difference indicated among the results obtained in the alkaline method is 0.20 per cent, whereas in the case of the acid method the corresponding figure is 0.53. The results obtained by the Harding-Parkin method are less satisfactory, although there are no serious criticisms upon this method, except that the method is rather time-consuming and involves a few cumbersome details. The results obtained upon the sample of dried milk, while hardly as satisfactory as could be wished, are nevertheless not especially disappointing when it is considered that the product was a skimmed milk powder containing about 0.1 per cent of butter fat. No decided preference seems to be indicated in the preliminary treatment of the sample in favor of either the alkaline or the acid method. The results obtained on the ice cream samples are very satisfactory, especially those obtained by the official Roese-Gottlieb procedure. The maximum and minimum variations cover a range of only 0.26 per cent. The results reported by the Harding- Parkin method are equally satisfactory and show even a somewhat smaller difference between the maximum and minimum values, 0.14 per cent. Barring the objection pointed out by a few of the collaborators regarding the time consumed in carrying out this latter procedure, it may be said that there is no decided preference regarding the relative merits of the Harding-Parkin method as compared with the official Roese-Gottlieb method applied to ice cream. An inspection of the results obtained on the two samples of cheese leads to the conclusion that the Schmidt- Bondzynski method is capable of yielding satisfactory results, especially when it is considered that there were somewhat greater difficulties to 210 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 be encountered in preparing and forwarding uniform samples of products of this class. The variations among the maximum and minimum values have a range of about 1.0 per cent, being in the case of the Parmesan cheese 1.15 per cent, and in the case of the American Pineapple 0.99 per cent. Considering, also, the high fat content of the cheese samples, it may be concluded that these results are approximately as good as may be expected in practical work. One or two of the collabora- tors have suggested criticisms regarding the tentative method for cheese, and appear to prefer the long discarded treatment employed in the application of the Werner-Schmidt method, which consisted in the digestion of the sample with dilute hydrochloric acid. There are also a few more or less positive differences of opinion expressed regarding the difficulties arising on account of the formation of foam. While there are certain analysts who encounter difficulties in the application of the alkaline method, there are others who apply the same criticism to the acid procedure. However, the consensus of opinion seems to favor the alkaline mode of preparing the sample and the practical difficulties indicated do not appear to be formidable. Such annoyances as trouble- some emulsions, foams, etc., can be overcome easily by proper exercise of ingenuity and ordinary analytical technique. On the whole, it is gratifying to conclude that the results reported are very satisfactory. RECOMMENDATIONS. It is recommended— (1) That the Roese-Gottlieb method, as applied to malted milk products and plain ice cream, be adopted as official. (2) That the Harding-Parkin method for fat in ice cream be adopted as a tentative method. (3) That the Schmidt-Bondzynski modified method for the deter- mination of fat in cheese be adopted as official. (4) That a further study be made of the Roese-Gottlieb method as applied to dried milk products having a high as well as a low content of butter fat. (5) That a study be made of methods for the determination of mois- ture in milk products, including condensed and sweetened condensed milk, dried milk and malted milk, and that the tentative method for the determination of moisture in cheese! be subjected to further study with a view to its adoption as an official method. 1 Assoc. Official Agr. Chemists, Methods, 1916, 296, 53. 1920) LEPPER: REPORT ON COFFEE 211 REPORT ON THE SEPARATION OF NITROGENOUS SUBSTANCES IN MILK AND CHEESE. By L. L. Van Styke (Agricultural Experiment Station, Geneva, N. Y.), Associate Referee. Last year it was recommended that study be continued leading to the adoption of methods for the determination of the non-casein proteins and the products of protein decomposition in milk. It was also recommended that collaborative work on the subject of enzym reactions of milk be undertaken. Before such enzym work can be done to advantage, much serious study must be made of the tests that are in use. The methods now used are largely empirical, and the interpretations based on the results of their use are far from satisfactory. A beginning was made in the study of the methylene blue reaction. The work, however, has been carried only far enough to reveal how much remains to be learned about the details of the action of this reagent in milk before it can be utilized as an intelligible and dependable means for practical use in relation to milk. The demands of this field are sufficient to require a separate referee to carry on research work, pre- paratory to collaborative investigations. The referee did not reach the special subject of non-casein proteins in milk. In his judgment further work remained to be done with casein and its separation from milk before taking up details involving the isolation of the other milk proteins and the study of their properties in pure form. The progress made by the referee on the preparation of pure casein! was then presented. No report on spices and other condiments was made by the referee. No report on cacao products was made by the referee. REPORT ON COFFEE. By H. A. Lepper (Bureau of Chemistry, Washington, D. C.), Referee. The StahIschmidt method for the determination of caffein in tea has been before the association since 1911 and was slightly modified and used for this determination on coffee in 19152. This modified method was recommended for official adoption this year. In view of the fact that very few collaborators offered their services in 1915 and that the method had little trial on coffee, some preliminary 1 J. Biol. chem., 1918, 35: 127. 2 J. Assoc. Official Agr. Chemists, 1917, 3: 21. 212 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 analyses were made by this method on several samples of coffee, yielding the results shown in Table 1. The nitrogen determinations reported by the referee were made by the Nitrogen Laboratory, Bureau of Chemistry, Washington, D. C. TABLE 1. Comparison of the Stahlschmidt and Fendler and Stiiber methods for the determination of caffein in coffee. STAHLSCHMIDT FENDLER AND STUBER RUB DESCRIPTION OF SAMPLE Gravimetric | N © 3.464 | Gravimetric | N 3.464 per cent per cent per cenl per cent 1 Santos medium roast......... 1233) ol Tents 1.23 1.14 1.33 Tile 1.23} 1.16 1.53 | 1.16 hehe sehen | | 2 Santos dark rOashasc ee ree 1.43 | 1.24 Be 1.14 1.52 1.24 118; =| 1.18 1.38 1.14 1.20 1.14 1.42 1.16 ce sae 1.37 1.14 AV CLAL CR se ye cara reoLae V4 1.18 V21 1.15 3 Coffee ‘‘caffein-free”.......... 0.25 0.09 0.09 0.05 0.23 0.09 0.09 | 0.05 0.27 0.12 i8 AG: 0.24 0.12 eon ANeragern th. cok. eee 0.25 0.11 0.09 | 0.05 These results on pure coffee compare favorably with those reported in 1915, showing a variation averaging 0.24 per cent in the values ob- tained by weighing the residue and by calculating from the nitrogen determinations. However, the values on a commercial sample of coffee (No. 3), labeled as coffee having 95 per cent of the caffein removed, are not so favorable. The results show that the caffein obtained contains impurities greater in weight than the alkaloid itself. Moreover, the amount of sample required by this method gave a weight of residue of about 5 mg., which, being less than one-half caffein, furnished a rather small sample for the determination of nitrogen. The errors incident to the nitrogen determination become relatively larger than with larger residues of crude caffein. As the so-called caffein-free coffees are becoming more plentiful and more widely used, it seemed desirable to the referee to have a method better adapted to these products and at the same time one which will give a purer crude caffein. The following method was chosen from among several!: 1J. Burmann. Bull. soc. chim., 1910, 7: 239; C. A., 1910, 4: 1777. C. Virchow. Chem. Zitg., 1910, 34: 1037; C. A., 1911, 5: 542. F. Adam. Arch. Chem. Mikros., 1910, 3: 212; C. A., 1911, 5: 1470. G. Costes. Ann. chim. anal., 1912, 17: 246; Analyst, 1912, 37: 401. 1920] LEPPER: REPORT ON COFFEE 213 DETERMINATION OF CAFFEIN IN COFFEE!. By G. Fendler and W. Stiiber. Pulverize the coffee to pass without residue through a 1 mm. sieve. Treat a 10 gram sample with 10 grams of 10% ammonium hydroxid and 200 grams of chloroform in a glass-stoppered bottle and shake continuously by machine or hand for 30 minutes. Pour the entire contents of the bottle on a 12.5 mm. folded filter, covering with a watch glass. Weigh 150 grams of the filtrate into a 250 cc. flask and evaporate on the steam bath, removing the last chloroform with a blast of air. Digest the residue with 80 cc. of hot water for 10 minutes on the steam bath, with frequent shaking, and let cool. Treat the solution with 20 cc. (for roasted) or 10 cc. (for unroasted) of 1% potassium permanganate and let stand 15 minutes at room temperature. Add 2 cc. of 3% hydrogen peroxid (containing 1 cc. of glacial acetic acid in 100 cc.). If the liquid is still red or reddish, add hydrogen peroxid, 1 cc. at a time until the excess of potassium perman- ganate is destroyed. Place the flask on the steam bath for 15 minutes, adding hydrogen peroxid in 0.5 cc. portions until the liquid ceases to become lighter. Cool, and filter into a separatory funnel, washing with cold water. Extract four times with 25 cc. of chloroform. Eyaporate the chloroform extract from a weighed flask with the aid of an air blast and dry at 100°C. to constant weight (30 minutes is usually sufficient). Weigh the residue as caffein and calculate on 7.5 grams of coffee. Test the purity of the residue by determining nitrogen and multiplying by the factor 3.464. Fendler and Stiiber, in considering more than twenty methods and studying those of C. C. Keller?, J. Katz’, and Lendrich and Nottbohm‘ found the last two to be trustworthy but long and tedious. They also found, as did the referee for 1910° and 1911°, that the Lendrich-Nott- bohm method gave an exceptionally pure caffein but low results unless the extraction was carried on for at least 6 hours. The exceptional purity of the caffein can be attributed to the action of potassium permanganate on the crude caffein residue, a procedure of purification employed originally by Lendrich and Nottbohm. Fendler and Stiiber after a study of the extraction, separation of the fat, purification and drying of the caffein, have retained the potassium permanganate purification in principle and have included it in a composite of the Katz and Lendrich-Nottbohm methods. Analyses were made on the same samples by this method by the Stahlschmidt method and the results are given in Table 1. The averages on pure coffee show a variation of 0.05 per cent between the weighed caffein and the calculated nitrogen value, indicating a much purer product than that obtained by the other method. The results on the “caffein-free” sample also show a very much purer caffein. Besides the advantage of yielding a residue only slightly contaminated, the Fendler-Stiiber 1 Z. Nahr. Genussm., 1914, 28: 9; C. A., 1914, 8: 3599. 2 Ber. pharm. Ges., 1897, 7: 105. 3 Tbid., P1902, 12: 250. +Z. Nahr. Genussm., 1909, 17: 5 U.S. Bur. Chem. Bull. 137: (dont), 106. § [bid., 152: (1912), 163. 214 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 method is easier of manipulation and much quicker than the Stahl- schmidt method and, at the same time, uses a sample three times as large. Three samples of coffee—A, “‘caffein-free’’ coffee purchased on the market; B, Santos medium roast; and C, Rio medium roast—were ground to pass a 1 mm. sieve without residue, were thoroughly mixed and sent to twelve collaborators with the request that they be examined by the Stahlschmidt! and the Fendler-Stiiber methods. Although the latter method was tried in its original form, it is believed that an improve- ment tending to easier, quicker, and more accurate manipulation is TABLE 2. Results of collaborative work on Sample A. CAFFEIN AN ALYST Stahlschmidt Fendler and Stiiber Gravimetric | N 3.464 | Gravimetric | N 3.464 per cent per cent per cent per cent H. J. Wichmann, U.S. Food and Drug 0.30 Petar 0.109 Inspection Station, Tabor Opera 0.31 ace 0.094 House Building, Denver, Colo. G. N. Watson, reported by L. E. Sayre, 0.22 0.189 0.117 0.095 School of Pharmacy, University of 0.22 eisie 0.085 ss Kansas, Lawrence, Kans. E. C. Merrill, Bureau of Chemistry, 0.237 Sick 0.18 Washington, D. C. Leicester Patton, U. S. Food and Drug 0.50 0.09 0.09 0.07 Inspection Station, Federal Building, Buffalo, N. Y. E. M. Bailey, reported by J. P. Street, 0.23 0.13 0.08 0.05 Agricultural Experiment Station, New Haven, Conn. C. E. Shepard, reported by J. P. Street. cares Ss 0.08 0.06 C. B. Gnadinger, reported by G. W. 0.25 0.10 0.09 0.06 Hoover, U. S. Food and Drug In- spection Station, Transportation Building, Chicago, Ill. C. K. Glycart, reported by G. W. 0.11 0.05* 0.04 0.04* Hoover. 0.06 He (Astieppers 2s DETAILS OF ELECTRODES PLATING? FULED IM BLASE OfPOSITION BATH FIG. 1. APPARATUS FOR ELECTROLYTIC DETERMINATION OF LEAD. Wiring Diagrams: Deposition Bath: Details of Electrodes: A = Ammeter. a = Anode (plate). Spiral = 30 cm. of No. 22 wire. B = Deposition bath. b = Beaker. Plate = Foil—25 mm. square. C = Switch. c = Cathode (spiral). R = Variable rheostat. S = Variable shunt. method. The placing of this cell in parallel gives an increased voltage across the re- maining cells and a resulting increased current in them which should be regulated by the variable resistance. The other cells may in turn and in a similar manner be removed from the series circuit and the electrodes washed by using the first replacement beaker with water and 2 cc. of hydrochloric acid, and the second with water alone. Following that the cathode is removed from the holder, washed in alcohol in a small beaker, and then the FIG. 2. ELECTROLYTIC SET-UP FOR PLANT CONTROL WORK. A—Ammeter. M—Main line switch. C—Electrolytic cell. O—Point in switch S intentionally left dead. L—Electric bulbs or other resistance. S—tTriple point double throw switch. 224 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 lead is dissolved with concentrated nitric acid heated gently. The lead is determined gravimetrically after precipitation as the chromate, or for plant control work may be determined colorimetrically by comparison with standard solutions. In Fig. 3 is shown a simple hinged arm for supporting the electrodes and enabling their shift from electrolytic cell to the beaker for resolution of the lead to be conven- iently made. The clamps, K, are simply wooden clothespins with a spring clamp; they are screwed to the long wooden arm, T, which is hinged to W, a wall support of wood. A flexible insulated copper cable is connected to the electrodes, Q, R, by a two point hard rubber dashlight connector, or other suitable means. During resolution of the lead from the cathode, the anode may be placed in the clamp, K’, out of the way. FIG. 3. ELECTRODE DETAILS. K—Electrode clamp. R—Cathode. K’—Extra anode clamp. T—Wooden arm electrode support. Q—Anode. W—Wall or other support. RESULTS OF COLLABORATORS USING CHITTICK METHOD. In Table 2 are given the results obtained for 1917 on Samples 1701, 1702, 1711, 1712, 1721 and 1722 of baking powder. The determinations of Exner, Malmstrom and Collins, Epstein, and Strunk are very con- sistent, on the whole, with themselves and with each other. Epstein’s values on Sample No. 1702 evidently were due to misnumbering the sample, as he hits almost exactly on the lead content of the control sample. Holbrook and Burkhardt are low but consistent. In ten de- terminations, Lyman approximates the actual lead content but his results, in the main, are not near the correct value. Clarke’s values are consistent but much too low. Exner has modified his former method and submits results for these samples obtained by it, as shown in the last 1920] PATTEN: REPORT ON BAKING POWDER 225 column of the table; but they are very much higher than his own results (using the Chittick method) which came very close to the actual value of the lead content. Consequently, further details of the Exner method will not be given at this time. The actual directions sent out to collaborators for the Chittick method are not those published in this report, since it was thought wise to publish this method in as perfect form as possible at the first writing and save the necessity for correction later, as well as confusion in the minds of analysts who may wish to use the method. Those who tried the method as first sent out will recognize at once the need of these changes. TABLE 2. Chittick method for lead in baking powders. LEAD FOUND She zt A ae F woe e -s aD SAMPLE TOTAL a5 = g.8 Es a = + NUMBER ceca % o5 © om 5 ES aq = et fe 2a = ZO = She | 3 at S. 2 £ ra Baie) s * perigee Des) eee eee se ate) | <5 rot Zz = =5 S) = = = 3 < = fa) < fe parts per | parts per | parts per | parts per | parts per | parts per | parts per | parts per | parts per million | million | million | million | million | million | million | million | million 1701 6 Some Rea Sues 6 1702 56 60.6 14.7 | 16.6 60 301 3.8 79 119 See 22.0 25.6 ae 305 5.1 Sars 96 41.0 aise Bis 232 ee 1711 4.8 1712 54.8 56.4 41.0 35.2 ae 118 30 48.4 $4 oe ee 38.0 30.7 67 55 Rode 80.8 ace 182 : sHioe aie 1721 3.2 | 1722 53.2 55.2 40.0 19.2 =o 65 48.7 48.4 82 43.6 21.8 as 60 Pe ee 83 * Carleton College, Northfield, Minn. + Victor Chemical Works, Chicago, Ill. {State Department of Agriculture, Atlanta, Ga. § Wilckes Martin Wilckes Company, Camden, N. J. ** Since deceased. 7+ Jaques Manufacturing Company, Chicago, Ill. {t.Using Exner’s method, modified. 226 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 RESULTS ON THE CORPER-BRYAN ELECTROLYTIC METHOD FOR LEAD IN BAKING POWDER. In Table 3 are given the findings of various collaborators using the Corper-Bryan method. Where the conditions of this method have been adjusted to reduce the high acidity originally mentioned in the method, very consistent and accurate results were obtained. TABLE 3. Electrolytic method for lead in baking powders. (Corper-Bryan Method.) LEAD FOUND 4 es) Eb = = te i | as) C =| & SAMPLE TOTAL < 2 g gs “ g g Bx 3 g NUMBER LEAD ¥ om %8 2s $= GE x oe PRESENT q £5 oe ss eS iE | § ae eg | g. Se | Se een ele so = 2 CP ieee Vice Peal am | m4 a ee Me | Se | a | Sd) | fae bl ee = 4 A < is) oe < < 5 < parts per | parts per | parts per | parts per | parts per | parts per | parts per | parts per | parts per million | million | million | million | million | million | million | million | million 1701 6 0 1702 56 49.3 67 cee 39 69 as Nega- 52 ones Sa 67 aoe 49 ats “Ne tive 59 85 a ne of results 1711 4.8 4.8 sfecsts 4.8 he 5.1 1712 54.8 50.6 52 42 24 53 Sovck 48.0 49 44 24 54 : 53 tks 1721 3.2 mies 26 3.2 oye whe 12 1722 53.2 45.4 51 23 33 tater 48.0 50 26 29 48 1074}f} 20 rs we 19.5 lets tow sz 20.5 * Larkin Company, Buffalo, N. Y. + Victor Chemical Works, Chicago, Ill. } Since deceased. U.S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, New York, N. Y- ** General Chemical Company, Laurel Hill, N. Y. +t Special baking powder used by Morey and Webster. 1920] PATTEN: REPORT ON BAKING POWDER 227 OTHER EXPERIMENTAL WORK. INVESTIGATION OF THE WICHMANN METHOD. In accordance with the findings for 1916, the referee and G. H. Mains made some experiments and outlined a method of investigation with a view to modifying the Wichmann method. The results obtained by the collaborators in this case were neither full nor satisfactory, but the method of working and the preliminary experiments have merit and are included here. OUTLINE OF EXPERIMENTS TO BE CARRIED ON WITH A VIEW TO MODIFYING THE WICHMANN METHOD. After consideration of the difficulty encountered in the Wichmann method, that phosphate made from rock bears relatively large amounts of iron and thus renders difficult the separation of lead and iron, in the precipitation as sulphids, an attempt was made to hold up the iron during the hydrogen sulphid precipitation. The hydrogen ion concentration, expressed in P,, value (Py = log a) was determined for the point at which the iron was just held up in hydrochloric acid solution. The accompanying notes give a description of this work. Having determined that at Pa = 3.3 iron will be held up and lead sulphid deposited when hydrogen sulphid is run in, it is desirable to determine whether or not under these conditions all of the lead present is precipitated as the sulphid. The following suggestions for the work are made in order to secure comparable results: 1. Make up a baking powder containing 27 parts by weight of sodium bicarbonate, sufficient monocalcium phosphate of the best quality and with lead content and neutral- izing power carefully determined exactly to neutralize the soda, and enough starch to make a total of 100 parts. The lead content of the sodium bicarbonate and of the starch should be determined. A determination of the per cent of iron present in the phosphate should likewise be made. 2. Take 100 gram portions of this completed baking powder mixture, place in 1.3 liter beakers, add 200 cc. of 10% hydrochloric acid to each, and heat on the steam bath until the starch is completely hydrolyzed. To different portions then add enough lead nitrate solution (0.320 gram per liter) to give, together with the amount of lead deter- mined in the baking powder ingredients, the following quantities of lead per 100 grams of baking powder: (a) 0.001 gram; (b) 0.002 gram; (c) 0.005 gram; (d) 0.010 gram: (e) 0.02 gram or 10, 20, 50, 100 and 200 parts per million, respectively. Dilute the baking powder solution containing added lead to 1 liter, and add 200 cc. of neutral ammonium citrate solution (lead-free), and cool to room temperature. 3. Test the solution for its P, value as follows: Place a 3 cc. portion of the solution in a test tube, and add 4 drops of the indicator tetrabromphenolsulphonephthalein. The concentration of the indicator is 0.1 gram in 250 ce. of alcohol'. This indicator turns from green to purple through a P, range of 3.3-4.5, showing the first faint tinge of purple at 3.3. If the sample in the test tube shows no purplish tint, add dilute ammonium hydroxid to the main solution, a few drops at a time, with constant stirring, and remove 3 cc. portions to test after each 1H. A. Lubs and W. M. Clark. J. Wash. Acad. Sci., 1915, 5: 609. 228 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 addition, until the value P, = 3.3 is reached. If this value is exceeded and the test tube sample shows more than a tint of purple color, dilute hydrochloric acid may be added a few drops at a time until the correct shade is obtained. 4. Having brought the solution to a Py value of 3.3 proceed with the precipitation of the lead sulphid, without the addition of mercuric chlorid as in the Wichmann method. Allow the lead sulphid to settle out overnight. Continue with the regular procedure through the weighing of the lead chromate. 5. Repeat this procedure (3) and (4), with a second series of solutions exactly as before, except that 15 cc. of saturated mercuric chlorid solution are added to each portion, and the treatment of the combined mercury and lead sulphids carried out according to the Wichmann method. This is to test the efficacy of the use of mercury to hasten the lead separation as recommended in this method. Whether or not at the acidity given, Py = 3.3, the mercury and lead will be clearly precipitated by hydrogen sulphid is to be determined. In case it is found that some of the lead is retained in solution in the first series of solutions, with no mercury present, the second series should still be run, as it may be found that with mercury present during the precipitation a more complete separation of lead and iron may be effected. Following this outline, A. H. Fiske and A. L. Thayer, working on a baking powder containing 0.55 per cent of iron, have obtained the results given in Table 4. It is evident that under the conditions of the Wich- mann method accurate results are not obtained, and that the addition of mercuric chlorid does not increase the accuracy. TABLE 4. Wichmann method. (A. H. Fiske, Collaborator; A. L. Thayer*, Analyst.) LEAD RECOVERED “= With 15 cc. of saturated mercuric chlorid LEAD PRESENT Without mercury solution: added. Lead found Recovery Lead found Recovery parts per million parts per miliion per cent parts per million per cent 10 4 40 22 220 20 0 0 20 100 50 i 14 28 56 100 90 90 24 24 200 50 25 101 50.5 * Rumford Chemical Works, Providence, R. I. EXPERIMENTS ON THE SOLUBILITY OF LEAD CHROMATE. The question was raised by some collaborators as to the solubility of lead chromate under the conditions of precipitation which obtain in the quantitative determination of lead in this form. Consequently, at the request of the referee, experiments were carried out as follows by A. H. Fiske: 1920] PATTEN: REPORT ON BAKING POWDER 229 Lead chromate was prepared by mixing solutions of lead nitrate and potassium dichromate which had been prepared from commercially C. P. material. The amounts mixed were approximately chemically equivalent. The precipitate was washed several times with hot water, redissolved in nitric acid and reprecipitated with ammonia in the presence of acetic acid. It was washed again several times by decantation with hot water and dried in the oven at 115°C. Great care was used to filter the solutions to make sure that no insoluble materials were present in the precipitate. The precipitation was done in flasks and the greatest care taken in every respect to avoid contamination. After cooling the precipitate in the desiccator and allowing it to stand in a weighing bottle in the balance case for 24 hours, charges of the material were weighed out into beakers and then warmed with 100 cc. of 20% acetic acid and 10 ce. of saturated dichro- mate solution. These proportions were used because it is recommended in the direc- tions for Bryan’s modification of the Corper method that 20 cc. of 20% acetic acid be used to dissolve the lead material and the solution then be precipitated with 2 cc. of saturated potassium dichromate solution. Thus, in each experiment, there is five times as much solution as was used in the precipitation of the lead chromate by the Corper- Bryan method. The beaker containing the solution and the lead chromate was heated on the steam bath for 2 hours with occasional stirring and was then allowed to cool overnight. The following morning, the temperature of the solution was taken, it was filtered on a weighed Gooch containing an asbestos mat, dried in the oven at 115°C. for 2 hours, and weighed. The loss in weight represents the amount of lead chromate dissolved in the solution. Irregularities in the results are probably due to the occlusion of soluble material in the original charge of lead chromate, because this work is usually supposed to be within a limit of error of 0.0002 gram. A tabular statement is given below of the loss of the lead chromate: TABLE 5. Difference between amount of lead chromate weighed out and the amount recovered. LEAD CHROMATE TEMPERATURE LEAD CHROMATE TEMPERATURE gram °G. gram &G; 0.0014 26 | 0.0030 23 0.0011 26 0.0008 23 0.0011 21 0.0008 23 Average difference in weight of lead chromate.................-..00-.-200005 0.0014 It will be noted from the above that the loss of the lead chromate in precipitation, using 20 ce. of 20% acetic acid and 2 cc. of saturated dichromate solution, must be very small if it is one-fifth of the average of the above. J. R. Davies (Calumet Baking Powder Company, Chicago, Ill.) car- ried out the following experiments: Lead chromate, made by the action of potassium dichromate on lead acetate, thor- oughly washed and dried, analysis showing 64.7 per cent of lead, was taken in amounts from 2.8-4.4 mg. This was brought into solution with 0.3 cc. of concentrated potassium 230 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 hydroxid solution, and sufficient water was added to make a total volume of 30 cc., with the addition of the required amount of acetic acid and potassium dichromate. This dilute solution of lead chromate in alkali was brought to the boiling point, when the dichromate solution and 5 cc. of acetic acid, plus that required to neutralize the potassium hydroxid used, were added simultaneously in order to approach the same conditions as obtained in the regular procedure. After the solution had stood for 18 hours at room temperature, the regular procedure was followed, filtering through tared Gooch crucibles, washing and drying the precipitate at 115°C. for 3 hours. The results appear in Table 6. The greatest loss was 0.2 mg., the greatest increase 0.1 mg. In the collaborative work of two or three years ago, a difference was obtained of at least 0.2 mg. in the weight of the same prepared crucible which had been dried and weighed repeatedly. It is evident that the solubility of lead chromate under these conditions is nil. TABLE 6. Solubility of lead chromate in potassium dichromate. (J. R. Davies, Analyst.) LEAD CHROMATE|LEAD CHROMATE POTASSIUM DICHROMATE ADDED RECOVERED ese a DICHROMATE IN SOLUTION mg mg. mg. mg. cc. per cent 4.1 4.1 0.0 ae 0.5 0.246 4.4 4.3 0.1 Ao6 0.5 0.246 3.8 3.6 0.2 soc 1.0 0.492 3.6 3.5 0.1 Sac 1.0 0.492 3.4 3.2 0.2 ios 2.0 0.984 3.4 3.3 0.1 SH 2.0 0.984 3.4 3.3 0.1 sa5 3.0 1.47 3.3 3.4 oon 0.1 3.0 1.47 3.2 3.0 0.2 one 5.0 2.46 3.2 3.2 0.0 RAD 5.0 2.46 3.2 3.3 Se 0.1 7.0 3.44 3.1 3.0 0.1 206 7.0 3.44 3.1 3.2 arte 0.1 8.0 3.93 3.0 3.1 0.1 8.0 3.93 2.9 3.0 bee 0.1 10.0 4.92 2.8 2.8 0.0 S0¢ 10.0 4.92 There is a statement! to the effect that if potassium dichromate is added to a neutral or very slightly acid solution of a lead salt, there is formed a basic lead chromate. As a precautionary method, the large amount of acetic acid was used. If a condition occurs where the basic chromate is formed, a large error will naturally result, the results show- ing a loss of lead. NEW METHODS SUBMITTED. ELECTROLYTIC METHOD FOR LEAD DETERMINATION. R. A. Holbrook and R. H. McCreary have worked out ar electrolytic method using a phosphoric acid solution and a rotating cathode. The time of electrolysis is much shortened, and they have obtained results 1 J. pharm. chimie., 1914, 10: 265. 1920) PATTEN: REPORT ON BAKING POWDER 231 on this year’s collaborative samples comparable with those obtained with the Corper-Bryan method. The method seems well worthy of study. The details as given by the authors follow: The method consists in separating the lead from the solution of the sample by elec- trolysis, dissolving the lead from the electrode, precipitating and weighing as PbCrO.. No attempt is made to decompose the starch. The electrical apparatus is a motor generator set, capable of generating 20 amperes at 6 volts, with field rheostat for control of voltage. A voltmeter and ammeter are necessary. The cell is an ordinary 800 cc. beaker, and the electrodes consist of a plat- inum wire anode of about 18 B. & S., gauge, with 2} inches submerged in electrolyte, and a gold cathode made of a disk 2 inches in diameter and soldered or rivetted on a gold spindle. Arrangements are made to rotate the disk at about 3000 revolutions per minute. A better cathode for this purpose would be of platinum, not more than 1} inches in diameter. DETAILS OF ELECTROLYSIS Weigh 100 grams of baking powder into a 800 cc. beaker and decompose by stirring in, a little at a time, 50 cc. of phosphoric acid (sp. gr. 1.75). When the reaction has subsided, add 400 cc. of water. The mixture is then ready for electrolysis. The electrodes are mounted so that the spindle of the cathode is at the bottom of the beaker and the disk } inch from the bottom, and the anode is adjusted to clear the disk of the cathode by } inch. The cathode is revolved and the current is turned on. With 6-7 volts potential drop across the cell, a current of 1.2 amperes is maintained. This corresponds to approximately 3.4 amperes per 100 square cm. of cathode surface ex- posed to electrolyte, since a part of the disk is not covered, which is due to the vortex caused by the high speed of rotation. No heat is applied. After 30 minutes’ electrolysis, quickly disconnect the cathode, dip in a beaker of water to wash off the electrolyte and place in a beaker just large enough to take the disk. Add enough strong nitric acid to cover the electrode, apply heat until the deposit is all dissolved, rinse off the electrode with a stream from a wash bottle and evaporate the solution to a volume of about 3 cc. Dilute this solution with 10 cc. of water and neu- tralize by adding ammonium hydroxid until a slight precipitate appears or until the solution is neutral to methyl orange, add 5 cc. of glacial acetic acid, boil the solution and, if there is a precipitate, filter, washing through with hot water. Bring the filtrate to the boiling point and precipitate the lead by adding 2 cc. of saturated potassium dichromate solution. Allow the precipitated lead chromate to settle overnight and filter off on a dried and weighed porcelain Gooch crucible with an asbestos pad, wash with cold water, dry at 110°C. for 1 hour, cool and weigh. The above method is applicable to monocalcium phosphate using 100 grams of sample, 25 cc. of phosphoric acid (sp. gr. 1.75) and 400 cc. of water. The time of elec- trolysis should exceed 1 hour. This amount of phosphate is not entirely soluble but good results can be obtained if the sample is as finely ground as in baking powder materials. METHOD OF DETERMINING FLUORIDS IN BAKING POWDER. During 1917 a method of broad range and great accuracy was elabo- rated by C. H. Wagner and W. H. Ross! (Bureau of Soils, Washington, D. C.) for the determination of fluorids. Some preliminary experiments 1 J. Ind. Eng. Chem., 1917, 9: 1116. 232 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 have shown this method to be well applicable to baking powders, and it deserves study and consideration. ACKNOWLEDGMENT. The referee wishes to express his appreciation of the assistance ren- dered by G. H. Mains and A. J. Johnson (Bureau of Chemistry, Wash- ington, D. C.), and likewise to the various collaborators mentioned in the tables. RECOMMENDATIONS. It is reeommended— (1) That the modified Corper-Bryan method for the electrolytic deter- mination of lead in baking powder (page 221) be adopted as a tentative method. (First reading.) (2) That a study be made of the electrolytic method, proposed by Holbrook and McCreary (page 230), in which a rotating cathode is used and which operates directly in an aqueous phosphoric acid suspension of the powder without preliminary hydrolysis of the starch. (3) That a study be made of the electrolytic separation and deter- mination of zinc in baking powder. (4) That a further study be made of Chittick’s method for the deter- mination of lead in baking powder (page 218). (5) That in view of the fact that Wichmann’s modification of the Seeker-Clayton method gives difficulty as applied to modern baking powders, no further study be made of this method at the present time. (6) That the Wagner-Ross method for total fluorids (page 131) be studied. (7) That efforts be made to develop a chemical method for the deter- mination of zinc in baking powders. 1920] PATTEN-MAINS: HYDROGEN ION CONCENTRATION 233 A NOTE ON THE HYDROGEN ION CONCENTRATION AT WHICH IRON IS PRECIPITATED FROM HYDRO- CHLORIC ACID SOLUTION BY AMMONIUM HYDROXID, SODIUM HYDROXID, AND HYDROGEN SULPHID. By H. E. Patren! and G. H. Matns (Bureau of Chemistry, Washington, D. C.). In working out the details of a method for determining lead in baking powders, tests were made as to the hydrogen ion concentrations at which ferric iron is precipitated from hydrochloric acid solution. A 1200 ce. solution containing 0.4 gram of iron in the form of ferric chlorid and 0.002 gram of lead in the form of lead nitrate was divided into 100 ce. portions. (The concentration of iron given corresponds to the maximum likely to be met with in phosphate baking powders.) To one of these portions, dilute ammonium hydroxid was added from a burette, a few drops at a time. The hydrogen ion concentration of the solution expressed as P,, (P,, =log a)? after each addition of ammonium hydroxid was determined by color comparison® using the following in- dicators, whose color changes had been checked by the hydrogen electrode. The indicators oa and their practical range of color changes were: M-Benzolsulfosaurediphenylamin P,, 1.2 to 2.3 Methyl orange P, 2.0 to 3.5 Tetrabromphenolsulphonephthalein Py 3.3 to 4.5 Methyl red Py 4.0 to 6.4 Phenolsulphonephthalein P,, 6.5 to 8.5 Rosolic acid Pe C.0ito 7-0 The P,, values may be considered as correct to +0.2. Ata P, of 3.3 the solution was perfectly clear. At P,, = 3.5 a very faint cloudiness, due to a colloidal precipitation of ferric hydroxid, could be seen. This became more pronounced as the P,, increased, giving a small amount of fine flocculent precipitate at P,, = 5.5 and becoming very heavy at P,, = 6.0. By the addition of hydrochloric acid the P,, was lowered, and the precipitate dissolved correspondingly, the solution becoming clear at P,, = 3.3. Duplicate results were secured on a second portion. The use of sodium hydroxid in place of ammonium hydroxid gave the same results as to the point at which the iron was held in solution. 1 Present address, Provident Chemical Works, St. Louis, Mo. 2 Cf. Leonor Michaelis. Die W Benes siet onenkonzente bon: Berlin, 1914; S. P. L. Sorenson. Compl. mena oe lab. Carlsberg, 1909, 8: = Cf. W. M. Clark and H. A. pee J. Bact., 1917, 2: 1. 234 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 By the addition of various amounts of sodium hydroxid and hydro- chlorice acid, respectively, several portions of the solution were brought to certain different hydrogen ion concentrations. The P, of each of these portions was then determined as before, and all of the portions were saturated with hydrogen sulphid gas. It was found that the highest P,, at which the iron was held in solution was approximately 3.3. Ata P,, of 3.5 a small amount of iron sulphid was precipitated, increasing in amount as the Py was increased. At P,, points lower than 3.3 the solu- tion remained clear, the iron being held up. This was checked with several solutions containing the above concentration of iron (0.03 per cent). It is customary to say that iron is precipitated by hydrogen sulphid from alkaline solutions, and not from acid solutions, without stating any definite limit as to the degree of acidity or alkalinity. We have found that iron in quantities up to 0.03 per cent can be held up in hydrochloric acid solutions at a P,, below 3.3, and that, in solutions of a higher P,, it is precipitated as ferrous sulphid by hydrogen sulphid. We have also found that when ammonium hydroxid or sodium hy- droxid is added to this same concentration of ferric iron in hydrochloric acid solution, the first formation of colloidal ferric hydroxid is noted at a P,, value very slightly greater than 3.3. This P,, value 3.3, at which iron is held up in hydrochloric acid solu- tions, may be conveniently obtained in practice as follows: Place a 3 cc. portion of the solution in a test tube, and add 4 drops of the indicator tetrabromphenolsulphonephthalein! (0.1 gram in 250 cc. of alcohol). This indicator turns from green to purple through a Py range of 3.3 to 4.5, showing the first faint tinge of purple at 3.3. If the sample in the test tube shows no purplish tint, add dilute ammonium hydroxid to the main solution, a few drops at a time, with constant stirring, and remove 3 cc. portions to test after each addition, until the value Py = 3.3 is reached. If this value is exceeded and the test tube sample shows more than a tinge of purple color, dilute hydrochloric acid may be added a few drops at a time until the correct shade is obtained. For the determination of other P,, values, indicators and comparison solutions of known P,, may be made as outlined by Clark and Lubs?. 1H. A. Lubs and W. M. Clark. J. Wash. Acad. Sct., 1915, 5: 609. 2 W. M. Clark and H. A. Lubs. J. Biol. Chem., 1916, 25: 479. 1920| PATTEN-MAINS: BEHAVIOR OF NEUTRAL AMMONIUM CITRATE =. 235 NOTE ON THE BEHAVIOR OF NEUTRAL AMMONIUM CITRATE IN CERTAIN PHOSPHATE SOLUTIONS. By H. E. Patten! and G. H. Mains, (Bureau of Chemistry, Washington, D. C.). In the methods for the determination of lead in phosphate baking powders the use of neutral ammonium citrate is specified, but there seems to be much uncertainty among analysts as to the function it per- forms, and the qualifying conditions for its use. Therefore, tests were made upon hydrochloric acid solutions of phosphate baking powder to determine the hydrogen ion concentration at which precipitates of cal- cium phosphate and calcium citrate are formed. The starch in a 100 gram sample of baking powder containing 56 grams of monocalcium phosphate was hydrolyzed by the addition of 300 cc. of concentrated hydrochloric acid, and the solution made up to 1 liter with water. This was divided into 100 cc. portions. To one of these, ammonium hydroxid was added a few drops at a time, and the Pe (Pe S log a) of the solution determined after each addition by color comparison, using indicators checked by the hydrogen electrode. P,, values given may be considered correct to + 0.2. When the Py had increased to 2.3, the first colloidal precipitate of calcium phosphate was formed, at a temperature of 26°C. Lowering the temperature to 10°C. brought no change in the amount of precipitate. Twenty cc. of neutral ammonium citrate solution (P,, = 7) were added, but did not cause an appreciable change in the volume of the precipitate. The P,, of the solution after the addition of the ammonium citrate was 5.5. Upon standing overnight, a heavy precipitate of calcium citrate settled out. By the addition of hydrochloric acid to the solution, the P,, was lowered gradually, the precipitate dissolving correspondingly, and the solution becoming clear at a P,, of 2.4. The P,, was again gradually increased by the addition of the ammonium hydroxid until a value of 6.0 was reached, with no formation of precipitate, the temperature of the solu- tion being 25°C. The solution was gradually heated over a Bunsen flame. At 95°C., a heavy precipitate of calcium citrate began to form, and settled rapidly. The P,, of the hot liquid was 6.2. To a second portion of the solution 20 cc. of neutral ammonium citrate solution were added, giving a P,, of 3.1. Ammonium hydroxid was very gradually added and the P,, determined at intervals as above. Small amounts of gelatinous calcium citrate, which dissolved upon stirring, were formed at each addition of the ammonium hydroxid. At P,, values of 5.0 and higher, the liquid appeared clear, but calcium 1 Present address, Provident Chemical Works, St. Louis, Mo. 236 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 citrate settled out on standing overnight. At P,, = 7.2, a permanent gelatinous precipitate of calcium citrate was formed. The temperature of the solution was 22°C. Another portion of solution gave the first permanent precipitate of calcium citrate at P,, = 7.1. Tests with ammonium molybdate solution showed that, when neutral ammonium citrate had been added to the phosphate solution, the pre- cipitates obtained by standing overnight or by raising the P,, to 7.1 were not calcium phosphate but calcium citrate. These experiments show that neutral ammonium citrate, when added to hydrochloric acid solution of phosphate baking powder, prevents the formation of a precipitate of calcium phosphate upon the addition of ammonium hydroxid. Calcium phosphate is held up in hydrochloric acid solution at P,, values more acid than 2.3 but precipitates at higher P,, values. When neutral ammonium citrate is added, the P,, is shifted greatly toward the alkaline end, tending still further to precipitate the phosphate. However, the ammonium citrate (broken up into citric acid) acts on the calcium phosphate, forming calcium citrate. At P,, values below 5.0, the calcium citrate is held in solution. At P,, values between 5.0 and 7.0, the precipitation is extremely slow in the cold, becoming noticeable only after several hours, but the precipitate settles out upon standing overnight. Raising the temperature of the solution hastens the precipitation. At P,, = 7.1, an immediate permanent precipitate of gelatinous calcium citrate is formed. After the precipitate is once formed, the addition of neutral ammonium citrate except in large excess will not clear up the solution. A comparatively small amount of hydrochloric acid, because of the sharp increase in hydrogen ion concentration (de- crease of P,,), rapidly dissolves the gelatinous calcium citrate. A convenient method of ascertaining the hydrogen ion concentration (P,,) of any solution is given herewith, since this determination has not yet come into general practice. The following directions are applicable only when a considerable volume of the solution to be tested is available. When a very small volume of solution is in n question, other methods must be used!. Take several test portions of 3 cc. each and place in test tubes, add 3 to 5 drops of the indicator solution, and observe the color-shade pro- duced. Each indicator solution has its own color change corresponding to a more or less definite hydrogen ion concentration. The quantitative directions for synthesizing and making up these indicator solutions are given by Clark and Lubs?, and the same authors’ have outlined very exactly a system of comparison solutions (or buffer solutions, as they 1G. S. Walpole. Biochem. J., 1913, 7: 410; Leonor Michaelis. Die Wasserstoffionenkonzentration. Berlin, Hols W. M. Clark and H. os “Labs. J. Bact., 1917, 2: 1. 2 J. Wash. Acad. Sci., 1915, 5: 609. 3 J. Bul. Chem., 1916, 25: 479. 1920| PATTEN-MAINS: BEHAVIOR OF NEUTRAL AMMONIUM CITRATE 237 term them) whose hydrogen ion concentration is determined by their quantitative composition, and is reproducible. The hydrogen ion value for each comparison solution is given, and opposite each value is given the color-shade of the appropriate indicator for that particular hydrogen ion concentration. Further quotation of the great number of references to the literature of this subject is not given here since this is well covered in the authori- ties cited. The specific indicators that we have used in the above work on citrate and phosphate solutions, together with their practical ranges of color change, are given below: M-Benzolsulfosaurediphenylamin P, 1.2 to 2.3. Methyl orange Py 2.0 to 3.5. Tetrabromphenolsulphonephthalein Py, 3.3 to 4.5. Methyl] red P, 4.0 to 6.4. Phenolsulphonephthalein Py 6.5 to 8.5. Rosolic acid P,, 7.0 to 7.5. J. K. Haywood made the following recommendations in behalf of the executive committee: It is recommended— (1) That the Committee on Amendment to the Constitution and By-Laws be discharged. This committee completed its work last year and should have been discharged at that time. Approved. (2) That the action of the president in appointing an associate referee on gelatin be approved. Approved. (3) That the action of the president in appointing an associate referee on eggs and egg products be approved. Approved. (4) That the Committee on Editing Methods of Analysis be continued for another year and that A. J. Patten be appointed to fill the vacancy due to the resignation of J. P. Street. Approved. (5) That a referee on the toxicity of feed, suggested by W. A. Withers of North Carolina, be not appointed, as it appears to the executive com- mittee that the work of a referee on this subject is somewhat outside the scope of the work of this association. Approved. 238 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (6) That no separate section be held on soils, since it does not appear to the executive committee that it would be to the best interests of the association to break up into sections. The program is so arranged now that soils are discussed in the main meeting while drugs are discussed in a separate room, which practically amounts to a separate session for soils. Approved. William Frear of Pennsylvania made the following motion, which was duly seconded and adopted, that the executive committee, in the prepa- ration of the program next year, be requested to keep carefully in mind this request of the soil chemists. He called attention to the fact that there were a great many subjects that required more time than has been given to them during the past five years. The meeting adjourned at 4.30 p. m. for the day. THIRD DAY. WEDNESDAY—MORNING SESSION. REPORT OF COMMITTEE ON RECOMMENDATIONS OF REFEREES. By B. B. Ross (Alabama Polytechnic Institute, Auburn, Ala.), Chairman. Your committee has made a report and has discharged a certain part of the duty assigned to it. As a result of the amendment to the consti- tution that was adopted a year ago, the Committee on Recommenda- tions of Referees is delegated or authorized to recommend to the President of the Association the names of referees and associate referees to work on each of the subjects to be considered by the association. At a joint meeting of the Executive Committee, the Committee on Recommenda- tions of Referees, and the President of the Association, this committee made such recommendations. The chairmen of the various subcommittees will report on the recom- mendations of the various referees that have been approved for the coming year. Probably owing to war time conditions, a number of recommendations made a year ago have not been carried out by the present referees. Wherever possible it is hoped that work along these lines will be conducted during the coming year. REPORT OF COMMITTEE A ON RECOMMENDATIONS OF REFEREES. By A. J. Parren (Agricultural Experiment Station, E. Lansing, Mich.), Chairman. [Phosphoric acid (basic slag, to cooperate with committee on vegetation tests on the availability of phosphoric acid in basic slag), nitrogen (special study of Kjeldahl method), potash, soils (nitrogenous compounds, lime requirements), inor- ganic plant constituents, insecticides and fungicides, and water.] PHOSPHORIC ACID. It is recommended that the following recommendations of 1916 be referred to the referee for 1918: (1) That the study of the preparation of neutral ammonium citrate solution, its use in determining reverted phosphoric acid and possible substitutes for it in this determination, be continued. Approved. 239 240 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (2) That in view of the conditions resulting from the European war, whereby the price of molybdic acid has been more than quadrupled and 100 per cent molybdic acid practically removed from the markets of the. United States, the referee study the determination of phosphoric acid with a view to recommending an optional method not requiring the use of molybdic acid. Approved. (3) That the volumetric method, dissolving the slag in sulphuric and nitric acids', be adopted as an official method for total phosphoric acid in basic slag. Approved. (4) That this association instruct its referee on phosphoric acid to give prominent attention to the question of methods of determining available phosphoric acid in slags, the chemical ingredients influencing the same, and the bibliography on the subject. Sufficient reports are already in the hands of your committee to be of service to the referee on phosphoric acid in his chemical investigations. It seems unnecessary to the committee to wait until all of the vegetation results are at hand before tentative methods of analysis are submitted to the association. Approved. (5) It is further recommended that the papers presented by H. D. Haskins? on “The Effect of Mass and Degree of Fineness on the Per- centage of Available Phosphoric Acid in Precipitated Phosphate’’ and by E. O. Thomas* on “Insoluble Phosphoric Acid in Organic Base Goods’’, be referred to the referee for 1918. Approved. NITROGEN. Tt is recommended— (1) That work on the West Coast refraction method be discontinued. Approved. (2) That the referee for 1918 study the Lunge nitrometer method, which is invariably used by the manufacturers of explosives, for the analysis of nitrate of soda. Approved. 1J. Assoc. Ohreir Agr. Chemists, 1917, 3: 90. 2 Ibid., 1920, 3 J. Ind. Eng. "ChE: 1917, 9: 865. 1920| PATTEN: COMMITTEE A ON RECOMMENDATIONS OF REFEREES 241 (3) That the use of 10 grams of anhydrous sodium sulphate as a substitute for potassium sulphate in the Gunning method and any modification thereof be made official. Approved. (4) That the use of potassium permanganate, wherever it appears in the Kjeldahl method, be eliminated. Approved. (5) That a further study be made of the effect of glass wool in the ferrous-sulphate-zinc-soda method for nitrates. Approved. POTASH. It is recommended— (1) That the work on the availability of potash be continued. Approved. (2) That the study of the perchlorate method be continued. Approved. (3) That the official method for the preparation of potash solution! be revised to read as follows: Place 2.5 grams of the sample upon a 12.5 cm. filter paper and wash with successive portions of boiling water into a 250 cc. graduated flask until the filtrate amounts to about 200 cc. Add to the hot solution a slight excess of ammonium hydroxid and sufficient ammonium oxalate to precipitate all of the lime present, cool, dilute to 250 cc., mix, and pass through a dry filter. Approved. (4) That the paper presented by H. D. Haskins’, entitled “A Modified Method for the Determination of Water-Soluble Potash in Wood Ashes and Treater Dust’’, be referred to the referee on potash for 1918. Approved. SOILS. It is reeommended— (1) That the recommendations held over from 1916% be rescinded and the referee on soils for 1918 be given authority to take up such work as seems in his judgment most necessary. Approved. 1 Assoc. Official Agr. Chemists, Methods, 1916, 12. 2 J. Assoc. Official Agr. Chemists, 1920, 4: 82. 3 [bid., 3: 520. 242 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (2) That the title, “Lime Requirement of Soils’’, be changed to “Lime Absorption Coefficient”. Approved. (3) That the work of the ensuing year be directed along lines which will fully develop the optimum conditions for carrying out the Jones method. Approved. INORGANIC PLANT CONSTITUENTS. It is recommended— (1) That the report of J. F. Breazeale! on “The Determination of Calcium in the Presence of Phosphates’ and the recommendations approved by the association in 1916? be referred to the referee for 1918. Approved. (2) That the methods as outlined for calcium, magnesium, iron and aluminium be further studied on solutions approximating the composi- tion of the ash from cereals. Approved. (3) That the colorimetric method for the determination of manganese be further studied. Approved. INSECTICIDES AND FUNGICIDES. It is reeommended— (1) That further cooperative work be done on the Gyory method for titrating arsenious oxid in hydrochloric acid solution with a solution of potassium bromate. Approved. (2) That further cooperative work be done on the determination of lead, copper and zinc in the analysis of such preparations as Bordeaux- lead arsenate, Bordeaux-zinc arsenite, etc. Approved. (3) That cooperative work be done on the determination of total arsenic in London purple by first destroying the color by heating the sample with a mixture of zinc oxid and sodium carbonate. Approved. 1 J. Assoc. Official Agr. Chemists, 1920, 4: 124. 2 Ibid., 3: 521. 3 Ibid., 329. 4 Ibid., 330. 1920] PATTEN: COMMITTEE A ON RECOMMENDATIONS OF REFEREES 243 (4) That cooperative work be done on the removal of coloring matter from London purple by the use of an adsorbent. Approved. (5) That the methods given by Roark! for total sulphur and for total lime be made official. Approved. (6) That methods for determining the monosulphid equivalent, thio- sulphate sulphur, sulphid sulphur, and sulphate sulphur under the iodin titration method’, be made tentative. Approved. (7) That the paper on “The Determination of Arsenic in Insecticides by Potassium Iodate” by George S. Jamieson® be referred to the referee for 1918. Approved. WATER. It is recommended— (1) That the method for the determination of barium‘ be adopted as official. Approved. (2) That the method for the determination of manganese® be adopted as an additional official method. Approved. (3) That further study be given to the rapid method for the deter- mination of calcium and magnesium in industrial water‘. Approved. (4) That further study be given to the determination of free and albuminoid ammonia in water containing sulphids, with a view to modi- fying the official method in this respect. Approved. (5) That the referee for 1918 be instructed to continue the work on water along the lines suggested in the Report of the Referee on Water for 1917, giving particular attention to the selection of methods for determining lead, copper, zinc and tin in waters, and to the calculation of the milligram equivalents of the radicals found in water with a view to their use in the interpretation of water analyses. Approved. inci at oe peat Agr. Chemists, 1920, 3: 354-5. 3 J. Ind. ie, Chem., 1918, 10: 290. a7: qe Official Agr. Chemists, 1920, 4: 86. 5 Tbid., 6 Ibid., 82. 244 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (6) That the methods listed below, recommended in 1916! for adop- tion as official, be adopted as official this year. (Second presentation of the methods for action.) (a) Method for the determination of lithium, potassium and sodium!. (b) Method for turbidity, 1 and 22. (c) Method for color, 3 and 4°. (d) Method for odor, 5°. (e) The Schulze-Trommsdorf method for the determination of required oxygen, 22 and 23°. (f) Method I and Method II for dissolved oxygen, 24, 25, 26, 27, 28 and 294, (g) Method for the determination of specific gravity, 30°. (h) Method for the determination of hydrogen sulphid, 37°. (i) Method for temporary hardness, 70°. (j) Method for alkalinity, 71, 72, 73 and 74°. (k) Method for total hardness, 75 andd 76’. (1) Method for permanent or non-carbonate hardness, 777. Approved. (7) That the method for free carbon dioxid’ remain a tentative method. (Second presentation of the method for action.) Approved. (8) That consideration be given to the Gutzeit method for the deter- mination of arsenic with a view to having it printed in the methods for the analysis of water (as an additional official method)*. (Second pre- sentation of the method for action.) Approved. (9) That the official reduction method for the determination of nitro- gen in the form of nitrate be revised to read as outlined in the 1917 Report of the Referee on Water”. Approved. 1 J. Assoc. Official Agr. Chemists, 1920, 3: 522. : rote hi Agr. Chemists, Methods, 1916, 35. id., 39. Cale al- 10 J. Assoc. Official Agr. Chemisls, 1920, 4: 92. 1920] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 245 REPORT OF COMMITTEE B ON RECOMMENDATIONS OF REFEREES. By H. C. LytHcor (State Department of Health, Boston, Mass.), Acting Chairman. [Foods and feeding stuffs (sugar, crude fiber, stock feed adulteration, organic and inorganic phosphorus, water), dairy products (separation of nitrogenous sub- stances in milk and cheese), saccharine products (maple products, honey, sugar house products), drugs (medicinal plants, alkaloids, synthetic products, medicated soft drinks, balsams and gum resins, enzyms), testing chemical reagents and microanalytical methods.] FOODS AND FEEDING STUFFS. It is recommended— (1) That a further study be made of sulphur dioxid in bleached grain. Approved. (2) That the method for determining the acidity of corn, as described by Black and Alsberg!, be considered by the referee next year with a view to its adoption as an official method, and that the method be studied to determine whether changes are necessary to make it applicable to grains other than corn. Approved. SUGAR. No recommendations were made by the referee. The committee therefore recommends that the following 1916 recommendations be continued: (1) That the modifications proposed in 1915 for determining sucrose by acid and invertase inversion be further studied. Approved. (2) That the work upon determining small amounts of reducing sugars in the presence of sucrose be continued. Approved. (3) That the methods of determining copper by reduction of the oxid in alcohol vapors be investigated. Approved. (4) That the optical methods for estimating raffinose in beet products be examined with special reference to hydrolysis by means of enzyms. Approved. 1U.S. Bur. Plant Ind. Bull. 199: (1910). 246 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (5) That details of mixing raw sugars be studied with a view to reduc- ing moisture changes. Approved. (6) That the influence of temperature upon polarization by sugars other than sucrose be studied. Approved. (7) That recommendations 2, 3 and 5 made by W. D. Horne! be referred to the Committee on Editing Methods of Analysis. Approved. (8) That the referees continue in collaboration with the Bureau of Standards the preparation of a table of reduction factors for the more common reducing sugars. Approved. CRUDE FIBER. (1) That the one filtration method? be further studied. Approved. (2) That the matter of a uniform filtering medium be further studied. Approved. STOCK FEED ADULTERATION. (1) That the work on scratch feed be continued with a view to secur- ing an accurate and satisfactory method of sampling. Approved. (2) That the work of developing a method for the quantitative deter- mination of cottonseed hulls in cottonseed meal be continued. Approved. ORGANIC AND INORGANIC PHOSPHORUS. (1) That the magnesia mixture method’ for the estimation of water- soluble inorganic phosphorus in flesh be adopted as an official method, with one minor change of detail, in the interest of economy of reagents, namely, that the amount of magnesia mixture used in extracts from 10 to 12 gram samples be reduced from 50 to 10 ce. The committee feels that sufficient collaboration has not been reported and recom- mends that final action be deferred until further collaboration. Final action postponed. 1 J. Assoc. Official Agr. Chemists, 1919, 3: 263. 2 Tbid., 256. 3 Ibid., 1916, 1: 562; 1919, 3: 264. 1920] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 247 (2) That further work be done with the magnesia mixture method! on brain; and that other glandular tissues be studied. Approved. (3) That the referee consider the report of J. B. Rather on ‘‘The Determination of Phytin Phosphorus in Plant Products’’’. Approved. WATER. It is recommended— (1) That the method for the determination of water in foods and feed- ing stuffs by drying in vacuum over sulphuric acid’ be adopted as official. (This method has been twice before recommended as an official method by the previous referee.) (Final reading.) Approved. (2) That the following method for the determination of water by drying over lime in vacuum be adopted as a tentative method, and be recommended for further study for the ensuing year: Lime-Vacuum Method for Moisture. Weigh 2 grams of the material into a suitable dish or crucible with a tightly fitted cover. Place in a vacuum desiccator over about 400 grams of freshly ignited powdered lime, and exhaust with a vacuum pump. After 24 hours, open the desiccator, forcing the incoming air through concentrated sulphuric acid, and make the first weighing. After weighing, replace the dish in the desiccator and repeat the process until constant weight is obtained. The lime should be changed on the third or fourth day and, with very wet substances, once again near the end of the process. Approved. (3) That the following method for the determination of water by drying over carbide in vacuum be adopted as a tentative method, and be recommended for further study: Carbide-Vacuum Method for Moisture. Weigh 2 grams of the material into a suitable dish or crucible with a tightly fitted cover. Place in a vacuum desiccator over about 400 grams of clean lumps of calcium carbide, and exhaust with a vacuum pump. After 24 hours, open the desiccator, forcing the incoming air through concentrated sulphuric acid, and make the first weighing. After weighing, replace the dish in the desiccator and repeat the process until constant weight is obtained. The calcium carbide should be changed on the third or fourth day and, with very wet substances, once again near the end of the process. Approved. 1 J. Assoc. Official Agr. Chemists, 1916, 1: 562; 1919, 3: 264. 2 J. Am. Chem. Soc., 1917, 39: 2506. 3 Assoc. Official Agr. Chemists, Methods, 1916, 79. 248 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 DAIRY PRODUCTS. It is reeommended— (1) That the Roese-Gottlieb method! for fat, as applied to plain ice cream, be adopted as official. (First reading.) Approved. (2) That the Harding-Parkin method? for fat in ice cream be adopted as a tentative method. (First reading.) Approved. (3) That the Schmidt-Bondzynski method’ modified for the deter- mination of fat in cheese be adopted as official. (First reading.) Approved. (4) That a further study be made of the Roese-Gottlieb method! as applied to malted milk and dried milk products of various fat content. Approved. (5) That a study be made of methods for the determination of moisture in milk products, including evaporated and condensed milk, dried milk, and malted milk. Approved. (6) That the tentative method for the determination of moisture in cheese* be further studied with a view to its adoption as an official method. Approved. SEPARATION OF NITROGENOUS SUBSTANCES IN MILK AND CHEESE. The committee recommends that the following recommendations, adopted at the 1916 meeting, be continued for further study: (1) That the referee for next year attempt to determine the relative amounts of some of the dissociation products in water-soluble and water-insoluble meat proteins. Approved. (2) That study be continued leading to the adoption of methods for the determination of the non-casein proteins and the products of protein decomposition in milk. Approved. 1 Assoc. Official Agr. Chemists, Methods, 1916, 289. 2 J. Ind. Eng. Chem., 1913, 5: 131. 2 Assoc. Official Agr. Chemists, Methods, 1916, 29 4 [bid., 296. 1920] LYTHGOE: COMMITTEE B ON RECOMMENDATIONS OF REFEREES 249 SACCHARINE PRODUCTS. No report or recommendations. DRUGS. It is recommended— (1) That the method for the determination of atropin in tablets’, with the following change relative to drying the alkaloidal residue, be made tentative: “Dry in vacuo to a constant weight, and weigh as atropin”’. Approved. (2) That further work be done on the methods for separating quinin and strychnin, and that a method be submitted to the collaborators, which has a reasonable certainty of yielding concordant results. Approved. (3) That work be continued to find new sources of supplies or proper substitutes for drugs not now obtainable. Approved. (4) That work be continued to determine the value of a more extended use of weights of unit volumes in the analysis of crude drugs and spices. Approved. (5) That comparative work be resumed on the ricin method for the assay of pepsin? and that the methods outlined for the identification and assay of pepsin be studied cooperatively. Approved. (6) That the appointment of the referee on balsam be continued, and that a study be made of the methods of demonstrating the difference between the natural and the artificial product. Approved. (7) That the work on mixtures containing synthetic products be continued. Approved. (8) That a further study be made of the methods for the determina- tion of strychnin in tablet triturates’®. Approved. 1 J. Assoc. Official Agr. Chemists, 1920, 3: 379. 2 Assoc. Official Agr. Chemists, Methods, 1916, 363. 3 J. Assoc. Official Agr. Chemists, 1919, 3: 189; 1920, 3: 379. 250 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (9) That a further study be made of the method for the determination of strychnin in liquids! where it occurs as the only alkaloid. Approved. TESTING CHEMICAL REAGENTS. No recommendations were made by the referee. The committee therefore recommends that the following 1916 recommendations be continued: (1) That the work on the determination of alcohol in pharmaceutical preparations be continued. Approved. (2) That the study of methods for the determination of the strength of acetic anhydrid be continued. Approved. (3) That work on the testing of purity of immiscible organic solvents be continued. Approved. MICROANALYTICAL METHODS. It is recommended that studies on quantitative methods be continued. Approved. REPORT OF COMMITTEE C ON RECOMMENDATIONS OF REFEREES. By R. E. DootitrtLe (Transportation Building, Chicago, IIl.), Acting Chairman. {Food preservatives, coloring matters in foods, metals in foods, fruits and fruit products, canned vegetables, cereal foods, wines, soft drinks (bottlers’ products), distilled liquors, beers, vinegars, flavoring extracts, meat and meat products (separa- tion of nitrogenous compounds in meat products, meat extracts), edible fats and oils, spices and other condiments, cacao products, coffee, tea, baking powder.| FOOD PRESERVATIVES. It is recommended— (1) That further work be done on Method II?, submitted for col- laborative work last year, for the determination of saccharin in the presence of mustard oil. Approved. 1 J. Assoc. Official Agr. Chemists, 1919, 3: 189; 1920, 3: 379. * [bid., 1920, 3: 505. 1920] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 251 (2) That other methods not dependent upon the sulphur component of saccharin be investigated. Approved. (3) That further work be done upon the determination of saccharin in baked flour preparations. Approved. (4) That the following methods be made official, the paragraph num- bers and titles being given as they appear in the Association of Official Agricultural Chemists, Methods, 1916, 141-54. (Final action): SALICYLIC ACID. 1 PREPARATION OF SAMPLE.—OFFICIAL. 2 Ferric Chlorid Test.—Qualitative—Offcial. 4,5 Colorimetric Method.—Quantitative —Official. BENZOIC ACID. 6, 7 PREPARATION OF SAMPLE.—OFFICIAL. Ferric Chlorid Test—Qualitalive —Official. 10 Modified Mohler Test.—Qualitative—Official. 11 Quantitative Method —Official. SACCHARIN. 12 Qualitative Test—Official. BORIC ACID AND BORATES. 14 Qualitative Test—Official. 15 Quantitative Method.—Official. FORMALDEHYDE. 16 PREPARATION OF SAMPLE.—OFFICIAL. 17 Phenylhydrazin Hydrochlorid Method —Official. 18 Hehner Method.—Official. 19 Leach Method.—Official. 20 Phenylhydrazin Hydrochlorid and Sodium Nitro-prussid Test.—Official. 21 Phenylhydrazin Hydrochlorid and Putassium Ferricyanid Test.—Official. 22 Phenylhydrazin Hydrochlorid and Ferric Chlorid Test—Official. 23 Phloroglucinol Method. FLUORIDS. 24 Method I.—Modified Method of Blarez—Official. 25 Method II.—Official. 252 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 SULPHUROUS ACID. 30 Method I.—Distillation Method.—Official. 31 Method II.—Direct Titration Method.— Official. 32 DETERMINATION OF FREE SULPHUROUS ACID.—OFFICIAL. FORMIC ACID. 38, 39, 40 Quantitative Method —Official. Approved. COLORING MATTERS IN FOODS. It is recommended— (1) That the study of the natural coloring matters be continued. Approved. (2) That the data secured during the past year relative to the be- havior of natural coloring matters with certain specified reagents be added to the table for the “Behavior of certain natural coloring matters with common reagents’! when this table is revised. Approved. METALS IN FOODS. It is recommended— (1) That the Penniman method for tin? be the subject of collaborative work during 1918. Approved. (2) That the Gutzeit method as modified during 1916* be the subject of collaborative work on baking powder materials during 1918. Approved. (3) That a study be made of methods for the determination of arsenic in gelatin and similar products. Approved. (4) That a study be made of methods for the determination of zinc, copper, and aluminium in foods. Approved. FRUITS AND FRUIT PRODUCTS. It is recommended that methods for the detection of pectin from apple pomace, used in the manufacture of jellies and jams, be studied. Approved. } Assoc. Official Agr. Chemists, Methods, Fee 166-7. yma OGicrat Agr. Chemists, 1920, 4 3 Tbt = 1920] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 253 CANNED VEGETABLES. It is recommended— (1) That the referee be instructed to study methods peculiarly adapted to the examination of canned foods, especially methods for the detection of spoilage and conditions which are likely to lead to spoilage. Approved. (2) That the methods for the hydrolysis of linamarin and the subse- quent determination of hydrocyanic acid! be adopted as tentative methods. Approved. CEREAL FOODS. It is recommended— (1) That the work on the determination of moisture, gluten, soluble carbohydrates, cold water extract, chlorin, and ash be continued. Approved. (2) That the referee for the coming year study methods for the deter- mination of fat in baked cereal products. Approved. WINES. No recommendation. SOFT DRINKS. It is recommended that the work of the present year, particularly that for the determination of ginger and of capsicum in ginger ale and other ginger drinks, be continued. Approved. DISTILLED LIQUORS. No recommendation. BEERS. No recommendation. VINEGARS. No recommendation. FLAVORING EXTRACTS. It is reeommended— 1 J. Assoc. Official Agr. Chemists, 1920, 4: 151. 254 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (1) That the following method for the determination of benzoic acid in almond extracts be adopted as tentative: Oxidation Method for Determining Benzaldehyde and Benzoic Acid Together. Measure 10 cc. of the extract into a 100 cc. flask, add 10 cc. of a 10% sodium hy- droxid solution, and 20 cc. of U. S. P. hydrogen peroxid solution; cover with a watch glass and place in a water oven. Oxidation of the aldehyde to benzoic acid begins almost immediately and should be continued 5-10 minutes after all odor of benzalde- hyde has disappeared, which usually requires 20-30 minutes. Remove the flask from the water oven, transfer the contents to 1 separatory funnel, rinsing off the watch glass, add 10 ce. of dilute sulphuric acid solution (1 to 5) and cool the contents of the funnel to room temperature under the water tap. Extract the benzoic acid with 4 portions of 25, 25, 20, and 20 cc. of ether, respectively, and wash the combined extracts with two portions of 5-10 cc. of water, or until all sulphuric acid is removed. Filter into a tared dish, evaporate at room temperature, dry overnight in a desiccator, and weigh the benzoic acid. Multiply the result by 10. Multiply the grams per 100 cc. of benzaldehyde obtained in the sample by 1.151 to obtain the equivalent of benzoic acid, and subtract this from the grams per 100 ce. of total benzaldehyde and benzoic acid obtained above. The difference will be grams of benzoic acid per 100 cc. of the extract. Approved. (2) That the Association of Official Agricultural Chemists, Methods, 1916, 265-9, be changed as follows: 35 (a), Phenylhydrazin solution. Line 2.—Eliminate the word “‘article’’ and substitute therefor the words “product in vacuo”, making the sentence read: ‘‘A sufficiently pure product can be obtained by distilling the commercial product in vacuo, rejecting the first portions coming over which contain ammonia.” 36, DETERMINATION. Line 1.—After the word ‘“Weigh” insert the words ‘accurately about’’, making the clause read: “Weigh accurately about 15 grams of the sample into a small, glass- stoppered flask;”’. 55, Hortvet and West Method Modified.—Tentative. Change the last sentence to read as follows: “Multiply the weight of salicylic acid so found by 9.33 to obtain the per cent by volume of methyl salicylate.” Approved. (3) That Wichmann and Dean’s qualitative method for coumarin in vanilla extract be studied with a view to its possible adoption as a pre- liminary test for the purpose of shortening the official method when coumarin is absent. The method is as follows: Make 10 ce. of extract alkaline with sufficient 10% sodium hydroxid solution, dilute with 15 cc. water, to reduce the alcoholic strength, and extract with 20 cc. of ether in a separatory funnel. The ether solution will be slightly colored when the brown lower 1920] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 255 layer has been drawn off. Add a few cc. of strong alcoholic potassium hydroxid solution and wash the mixture with 10 cc. of water. The ether layer will be white. This pro- cedure removes all organic acids, coloring matter or saccharin that may be present. Place 1 cc. of 50% potassium hydroxid solution in a test tube and pour the ether solu- tion of coumarin over it. After thoroughly shaking, hastily evaporate the ether. Then place the tube over a free flame and evaporate the water and fuse the potassium hydroxid. If coumarin is present in any amount, a change of color will be noticed as the evapora- tion of the water proceeds and fusion begins. Even very small quantities of coumarin in strong hot potassium hydroxid solution will show a greenish color that suddenly disappears as the heating is continued. The disappearance of the color shows that the coumarin has been converted into the salicylate and heating should be discontinued. Take up the melt with a few cc. of water, acidify the solution with sulphuric acid and extract in a small separatory with 5-10 cc. of benzol. Benzol is preferred to any other solvent because of its low density, low solvent power for mineral acids, and because it will not dissolve any protocatechuic acid formed from vanillin that might possibly have been carried over with the ether. Remove the acid solution from the separatory and wash the benzol with a few cc. of water. After washing, filter the benzol into a test tube and test for salicylic acid with 1-2 cc. of water, containing a few drops of ferric chlorid solution. If no color develops on shaking, add 1-2 drops of N/10 sodium hydroxid solution to neutralize any trace of mineral acid that may be present and prevent the development of the purple color. This test can be conducted easily in 15 minutes, takes only 10 cc. of extract, and does not require dealcoholization or any complicated apparatus. The only evaporation necessary, that of the ether, can be done on a steam bath without appreciable loss. The change of color on fusion indicates its own end point. Approved. (4) That methods of analysis for imitation vanilla preparations con- taining large quantities of coumarin and vanillin be studied. Approved. (5) That the applicability of Hortvet and West’s method! for alcohol in orange and lemon extract, with F. M. Boyle’s details for alcohol in ginger extract, be considered in connection with the official methods and other available methods. Boyle’s method is as follows: To 25 ce. of the ginger extract, add 50 cc. of water, saturate with salt and shake with 75 cc. of petroleum ether. Allow to stand for 10 minutes, draw off the lower layer into a 200 cc. flask. Wash the petroleum ether with 50 cc. of saturated salt solution. This washing must be done carefully with moderate shaking, to avoid the formation of an emulsion. A slight emulsion at this point may be broken up by pouring back and forth into two separators. Add this wash water to the 200 cc. flask and make up to the mark with salt solution. Filter through a rapidly acting folded filter and determine the alcohol in 100 cc. of the filtrate by distillation. Approved. (6) That Mitchell’s polarization method? for lemon and orange ex- tracts be studied for the purpose of determining ihe most accurate 1 J. Ind. Eng. Chem., 1909, 1: 84. 2 Assoc. Official Agr. Chemists, Methods, 1916, 262. 256 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 factors to be used, especially with reference to the natural variations in the oils and the influence of dilution. Approved. (7) That Albright’s details of the Kleber method for citral in lemon and orange oils! be studied. Approved. MEAT AND MEAT PRODUCTS. No recommendations. SEPARATION OF NITROGENOUS COMPOUNDS IN MEAT PRODUCTS. No recommendations. MEAT EXTRACTS. No recommendations. EDIBLE FATS AND OILS. It is recommended that the method for the detection of the adultera- tion of lard with fats containing tristearin? be adopted as a tentative method. Approved. SPICES AND OTHER CONDIMENTS. It is recommended— (1) That the associate referee’s modification of the distillation method for determining moisture in whole spices* be further studied with a view to its adoption by the association. Approved. (2) That the method for the determination of volatile oil in mustard seed and mustard substitutes* be adopted as tentative. Approved. CACAO PRODUCTS. No recommendations were received from the referee. Your commit- tee, however, has been informed that the referee has had under investi- gation methods for the detection of adulteration in cocoa butters. It is therefore recommended that these studies be continued. Approved. 1 J. Assoc. Official Agr. Chemists, 1920,3: 417. 2 Ibid., 4: 200. 3 Ibid., 3: 428. 4 Ibid., 4: 149. 1920] DOOLITTLE: COMMITTEE C ON RECOMMENDATIONS OF REFEREES 257 COFFEE. It is reeommended— (1) That the Gorter method for the determination of caffein in coffee! be dropped. Approved. (2) That the Stahlschmidt method for the determination of caffein in coffee! be not made official this year. Approved. (3) That the Fendler-Stiiber method for the determination of caffein in coffee? be adopted tentatively. Approved. (4) That the Fendler-Stiiber method for the determination of caffein in coffee? be tried on other coffees, including raw coffee, with a view to its adoption as official next year. Approved. TEA. No recommendations. BAKING POWDER. It is recommended— (1) That the modified Corper-Bryan method for the electrolytic deter- mination of lead in baking powder® be adopted as a tentative method. (First reading.) Approved. (2) That a further study be made of the electrolytic method proposed by Holbrook and McCreary‘, which uses a rotating cathode, and operates directly in an aqueous phosphoric acid suspension of the powder without preliminary hydrolysis of the starch. Approved. (3) That a study be made of the electrolytic separation and deter- mination of zinc in baking powder. Approved. (4) That a study be made of Chittick’s method for the determination of lead in baking powders’. Approved. 1 Assoc. Official Agr. Chemists, Methods, 1916, 332. 2 J. Assoc. Official Agr. Chemists, 1920, 4: 213. 3 [bid., 221. + Ibid., 230 5 Ibid., 218. 258 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 (5) That in view of the fact that Wichmann’s modification of the Seeker-Clayton method gives difficulty as applied to modern baking powders, no further study be made of this method at the present time. Approved. (6) That the Ross-Wagner method for total fluorids! be studied. Approved. (7) That efforts be made to develop a commercial method for the determination of zinc in baking powders. Approved. REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS?. Your committee on Editing Methods of Analysis begs leave to report that the instructions given by the association at the 1916 meeting’ have been carried out as follows: (1) The following general reference tables have been removed from the text of the several chapters and inserted in a separate chapter designated as Chapter XXX: 1 Munson and Walker’s Table‘. For calculating dextrose, invert sugar alone, invert sugar in the presence of sucrose, etc. 2 Krober’s Table®. For determining pentoses and pentosans. 3 Table for densities of solutions of cane sugar at 20°C.*. 4 Table of temperature corrections for changing percentages of sugar by specific gravity to true values at 20°C.’. 5 Geerlig’s Table’. For dry substances in sugar-house products by the Abbé refrac- tometer, at 28°C. 6 Table of corrections for temperature to be used in conjunction with Table No. 5°. 7 Alcohol Table'®. For calculating the percentages of alcohol in mixtures of ethyl alcohol and water from their specific gravities. 8 Alcohol Table'!. For calculating the percentages of alcohol in mixtures of ethyl alcohol and water from their Zeiss immersion refractometer readings at 17.5°-25°C. 1 J. Ind. Eng. Chem., 1917, 9: 116. 2 Presented by R. E. Doolittle. 3 J. Assoc. Official Agr. Chemists, 1920, 3: 537. 4 Assoc. Official Agr. Chemists, Methods, 1916, 88-96. 5 Ibid., 112-7. 6 Ibid., 125-6. 7 U.S. Bur. Standards, Cire. 19: (1916), 25. 8 Assoc. Official Agr. Chemists, Methods, 1916, 127. § [bid., 128. 10 [bid., 194-207. 1 Thid., 208-35. 1920] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 259 (2) There has been included in Chapter XXX a table of the Inter- national Atomic Weights for 1916. (3) The word “‘chlorids’ has been substituted for the word “‘chlorin”’ in the phrase “wash free from chlorin”’ and similar phrases. (4) The gravimetric factors have been restored to the body of the text, these factors being based upon the atomic weights given in the atomic weight table included in Chapter XXX. (5) Specific directions for the preparation of solutions by weight or volume have been substituted in those methods in which the strength of solutions was expressed in terms of per cent. (6) The methods and changes in methods reported by the referees and adopted by the association in 1916 have been included in the revised methods. (7) The deletions, additions, and changes recommended by the Com- mittee on Editing Methods of Analysis at the 1916 meeting and approved by the association, together with those recommendations made from the floor of the meeting, and adopted by the association, have been made with the following exception: Under Chapter IIT, Inorganic Plant Constituents, cross references to methods under “‘Soils’’, have not been changed to references to methods under ‘‘Waters”’. Your committee found that this change of the cross references from “Soils” to ‘Waters’ would necessitate a complete rewriting of the methods under Inorganic Plant Constituents, including changes in pro- cedure in the methods. The methods under Chapter IV, Waters, are differently grouped from those under Inorganic Plant Constituents and provide for the determination of elements not included under Inorganic Plant Constituents. In order to comply with this motion, it would have been necessary to rewrite entirely the methods under Inorganic Plant Constituents, in most cases giving the methods in detail without cross references. Often these details were different from the official methods for Inorganic Plant Constituents adopted by the association. It is therefore recommended that the methods as now submitted, which disregard the motion, be approved. It is further recommended that the 1916 motion be referred to the referee on Inorganic Plant Constituents. (8) The use of proper names in the titles of methods has been omitted in so far as possible. Only such names have been retained as serve to identify properly certain procedures. (9) Careful consideration has been given to the methods designated as “Provisional” in Bureau of Chemistry Bulletin 107, Revised, and “Tentative” in the revised methods printed in supplements to the 260 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 Journal of the Association of Official Agricultural Chemists in 1916 for criticism, and your committee recommends that the rules be suspended and the following methods be made official (final action): I. FERTILIZERS'. 1, MECHANICAL ANALYSIS OF BONE AND TANKAGE. THOMAS OR BASIC SLAG. 46, MECHANICAL ANALYSIS. 47, PREPARATION OF SAMPLE. 48, 49, Gravimetric Method. Ill. INORGANIC PLANT CONSTITUENTS. 18, CHLORIN IN PLANTS. VII. INSECTICIDES AND FUNGICIDES. 57, Modified Method of Benedikt and Lewkowitsch. 58, POTASSIUM AND SODIUM. Vill. FOODS AND FEEDING STUFIFS. 3, Drying in Vacuo Without Heat. 12, GENERAL DIRECTIONS FOR RAW SUGARS. 13, PREPARATION AND USE OF CLARIFYING REAGENTS. 15, 16, By Polarization Before and After Inversion with Invertase. 18, DETERMINATION OF SUCROSE FROM REDUCING SUGARS BEFORE AND AFTER INVERSION. 24, 25: Munson and Walker General Method. 26, I. Direct Weighing of Cuprous Oxid. 28, 29, I. A. H. Low Volumetric Method, Modified. 30, III. Volumetric Permanganate Method. 31, IV. Electrolytic Deposition from Sulphuric Acid Solution. 32, V. Electrolytic Deposition from Sulphuric and Nitrie Acid Solution. 33, VI. Electrolytic Deposition from Nitric Acid Solution. 34, VII. Reduction in Hydrogen. 35, 36, 38, 39, Herzfeld Gravimetric Method. 42, General Gravimetric Method. 1 The references given are to the Assoc. Official Agr. Chemists, Methods, 1916. 1920| REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 43, 44, 45, Wein Method. 46, General Gravimetric Method. 52, General Gravimetric Method. 53, 54, 55, Allihn Gravimetric Method. 56, REDUCING SUGARS OTHER THAN DEXTROSE. 61, 62, Diastase Method with Subsequent Acid Hydrolysis. 63, 64, PENTOSANS. IX. SACCHARINE PRODUCTS. 1, PREPARATION OF SAMPLE. 3, Drying upon Pumice Stone. 4, Drying upon Quartz Sand. 10, REFRACTOMETER METHOD. 17, SOLUBLE AND INSOLUBLE ASH. 18, ALKALINITY OF THE SOLUBLE ASH. 19, ALKALINITY OF THE INSOLUBLE ASH. 21, NITROGEN. 22, Method I. 23, Method II. (Double Dilution Method.) 24, Method I. 25, Method II. tbe ALCOHOL IN SIRUPS USED IN CONFECTIONERY (“BRANDY DROPS”). HONEY. 34, PREPARATION OF SAMPLE. 35, MOISTURE. 37, SOLUBLE ASH. 38, ALKALINITY OF THE SOLUBLE ASH. 41, REDUCING SUGARS. 42, sUCROSE. 46, FREE ACID. MAPLE PRODUCTS. 53, PREPARATION OF SAMPLE. 54, MOISTURE. 261 262 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 55, POLARIZATION. 56, REDUCING SUGARS AS INVERT SUGAR. 57, By Polarization. 58, By Reducing Sugars Before and After Inversion. 59, TOTAL ASH. 60, SOLUBLE AND INSOLUBLE ASH. 61, ALKALINITY OF THE SOLUBLE ASH. 62, ALKALINITY OF THE INSOLUBLE ASH. X. FOOD PRESERVATIVES. 3, Jorissen’s Test.—Qualitative. 13, Quantitative Method. XIII. FRUITS AND FRUIT PRODUCTS. PREPARATION OF SAMPLE. . ALCOHOL. - TOTAL SOLIDS. Direct Method. Indirect Method. - - ALKALINITY OF THE ASH. - SULPHATE AND CHLORID. ¥ Soe Jee fa eS TOTAL ACIDITY. . 10, VOLATILE AcIDs. 14, By Reducing Sugars Before and After Inversion. 15, REDUCING SUGARS. 16, COMMERCIAL GLUCOSE. 18, ALCOHOL PRECIPITATE. 19, Qualitative Test. XIV. CANNED VEGETABLES. » PREPARATION OF SAMPLE. » MOISTURE. » TOTAL ACIDS. aon AW N » VOLATILE ACIDS. 1920) XVI. WINES. 3 PREPARATION OF SAMPLE. » SPECIFIC GRAVITY. 2 3 4, ALCOHOL. 4 >» Method I. (By Direct Weighing.) 8, Method II. (By Oxidation with Dichromate.) 9, GLYCEROL IN SWEET WINES. 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, GLYCEROL-ALCOHOL RATIO. From the Specific Gravity of the Dealcoholized Wine. By Evaporation. NON-SUGAR SOLIDS. REDUCING SUGARS. By Reducing Sugars Before and After Inversion. By Polarization. COMMERCIAL GLUCOSE. ASH. ASH-EXTRACT RATIO. ALKALINITY OF THE WATER-SOLUBLE ASH. ALKALINITY OF THE WATER-INSOLUBLE ASH. PHOSPHORIC ACID. SULPHURIC ACID. CHLORIN. TOTAL ACIDS. Method I. Method II. (Hortvet Method.) FIXED ACIDS. TOTAL TARTARIC ACID. FREE TARTARIC ACID AND CREAM OF TARTAR. CRUDE PROTEIN. PENTOSANS. REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 263 264 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 XVII. DISTILLED LIQUORS. 1, SPECIFIC GRAVITY. 4, Method IT. 7, ACIDITY. 8, ESTERS. 9, 10, ALDEHYDES. 11, 12, FuRFURAL. 13, 14, FUSEL om. 15, suGaRs. 16, Trillat Method. 17, Riche and Bardy Method. 18, Immersion Refractometer Method. (Leach and Lythgoe.) XVIII. BEERS. 1, PREPARATION OF SAMPLE. 3, SPECIFIC GRAVITY. 4, ALCOHOL. 7, Method ITI. 8, EXTRACT OF ORIGINAL WORT (APPROXIMATE). 9, DEGREE OF FERMENTATION. 10, ToTaL acrDs. 11, VOLATILE ACIDS. 12, REDUCING SUGARS. 15, GLYCEROL. 17, PHOSPHORIC ACID. XIX. VINEGARS. 2, PREPARATION OF SAMPLE. 3, SPECIFIC GRAVITY. 5, 6, GLYCEROL. 7, SOLIDS. 8, TOTAL REDUCING SUBSTANCES BEFORE INVERSION. 9, REDUCING SUGARS BEFORE INVERSION AFTER EVAPORATION. 10, REDUCING SUGARS AFTER INVERSION. 1920| REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, ASH. SOLUBLE AND INSOLUBLE ASH. ALKALINITY OF THE SOLUBLE ASH. SOLUBLE AND INSOLUBLE PHOSPHORIC ACID. TOTAL ACIDS. FIXED ACIDS. VOLATILE ACIDS. COLOR. Fincke Method. PENTOSANS. Qualitative Test. TOTAL TARTARIC ACID. XX. FLAVORING EXTRACTS. VANILLA EXTRACT AND ITS SUBSTITUTES. 1, SPECIFIC GRAVITY. 4, 5, Modified Hess and Prescott Method. 6, NORMAL LEAD NUMBER. 7, TOTAL SOLIDS. 10, 12, 17, 18, 20, ot, 22, 24, 28, 29, 32, 33, SUCROSE. METHYL ALCOHOL. LEMON AND ORANGE EXTRACTS. SPECIFIC GRAVITY. ALCOHOL. By Polarization. (Mitchell Method.) By Precipitation. (Mitchell Method.) 23, Chace Method. 25, Hiltner Method. SUCROSE. METHYL ALCOHOL. LEMON AND ORANGE OILS. SPECIFIC GRAVITY. INDEX OF REFRACTION. 265 266 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 34, OPTICAL ROTATION. 35, 36, Kleber Method. 37, Hiliner Method. 38, Chace Method. 39, PHYSICAL CONSTANTS OF THE 10 PER CENT DISTILLATE. 49, Chace Method. XXI. MEAT AND MEAT PRODUCTS. MEAT. 1, PREPARATION OF SAMPLE. 2, MOISTURE. 5, TOTAL PHOSPHORUS. MEAT EXTRACTS AND SIMILAR PRODUCTS. 32, PREPARATION OF SAMPLE. 33, MOISTURE. 35, TOTAL PHOSPHORUS. 36, CHLORIN. XXII. DAIRY PRODUCTS. MILK. 6, Method I. 7, Method II. 16, AcETIC SERUM. CHEESE. 56, acrDITy. XXIII. FATS AND OILS. 20°C. ro) 2, At 5, General Directions. 11, Capillary Tube Method. 12, 13, Alcoholic or Aqueous Sodium Hydroxid Method. 14, Glycerol-Potassium Hydrorid Method. 28, Polenske Method. 31, Benedikt-Lewkowitsch Method. 34, UNSAPONIFIABLE RESIDUE. 37: Modified Renard Test. 1920| REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 1, 4, 5, 8, 5 ’ XXIV. SPICES AND OTHER CONDIMENTS. SPICES. PREPARATION OF SAMPLE. SOLUBLE AND INSOLUBLE ASH. ASH INSOLUBLE IN ACID. Winton, Ogden and Mitchell Method. VOLATILE AND NON-VOLATILE ETHER EXTRACT. 10, ALCOHOL EXTRACT. 12, copPER-REDUCING SUBSTANCES BY DIRECT INVERSION. 13, sTARCH. 14, cRUDE FIBER. 15, TANNIN. PREPARED MUSTARD. 23, PREPARATION OF SAMPLE. 24, soLips. 26, SALT. 29, acIDITY. 30, COPPER-REDUCING SUBSTANCES. TOMATO PRODUCTS. » PREPARATION OF SAMPLE. » ALKALINITY OF THE ASH. » REDUCING SUGARS BEFORE INVERSION. » REDUCING SUGARS AFTER INVERSION. 44, sucROSE. 45, TOTAL ACIDS. , VOLATILE ACIDS. 48, FIXED ACIDS. 1, 4, 5, 6, 7, XXV. CACAO PRODUCTS. PREPARATION OF SAMPLE. ASH INSOLUBLE IN ACID. SOLUBLE AND INSOLUBLE ASH. ALKALINITY OF THE SOLUBLE ASH. ALKALINITY OF THE INSOLUBLE ASH. 12, Fat. 267 268 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 XXVI. COFFEES. ROASTED COFFEE. 4, PREPARATION OF SAMPLE. 8, ASH INSOLUBLE IN ACID. 9, SOLUBLE AND INSOLUBLE ASH. 10, ALKALINITY OF THE SOLUBLE ASH. 11, SOLUBLE PHOSPHORIC ACID IN THE ASH. 12, INSOLUBLE PHOSPHORIC ACID IN THE ASH. 16, CRUDE FIBER. 19, PETROLEUM ETHER EXTRACT. XXVII. TEA. 2, PREPARATION OF SAMPLE. 3, MOISTURE. 6, SOLUBLE AND INSOLUBLE ASH. 7, ASH INSOLUBLE IN ACID. 8, ALKALINITY OF THE ASH. 9, PHOSPHORIC ACID IN THE ASH. 10, PETROLEUM ETHER EXTRACT. 12, cRUDE FIBER. XXVIII. BAKING POWDERS AND THEIR INGREDIENTS. 1, PREPARATION OF SAMPLE. 3, 4, 5, Method Using Knorr’s Apparatus. 6, 7, 8, Method Using Heidenhain’s Apparatus. 9, RESIDUAL CARBON DIOXID. 10, AVAILABLE CARBON DIOXID. 11, acrpiry. 13, Goldenberg-Geromont-Heidenhain Method. 14, Qualitative Test. 15, Quantitative Method. 16, POTASSIUM BITARTRATE. 17, Direct Inversion Method. 18, Indirect Method. 1920] REPORT OF COMMITTEE ON EDITING METHODS OF ANALYSIS 269 20, Qualitative Test. 21, INSOLUBLE ASH AND PREPARATION OF SOLUTION. 22, IRON AND ALUMINIUM. 23, CALCIUM. 24, POTASSIUM AND SODIUM. 26, SULPHURIC ACID. 27, AMMONIA. Respectfully submitted, R. E. DoouittT1e, W. A. WITHERS, A. F. SEEKER, J. P. STREET, G. W. Hoover, B. L. Hartwe tt, Committee on Editing Methods of Analysis. Adopted. 270 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 REPORT OF SECRETARY-TREASURER FOR By C. L. AtsBere (Bureau of Chemistry, RECEIPTS. 1916 Nov.-14 Bank balance’). 2: aosc.ces., oe fencing eo alse nistanoae st eee era bee $221.07 Noy. 22 1915-16 dues from 4 organizations (Oakland, Calif., Canada, Wis- consin and Pennsylvania) received after the Secretary-Treasurer’s report for 1916 had been made out.................---2-2000: 8.00 1917 Noy. 12 Dues for the year 1916-17 from 76 Federal, State, Municipal and Canadian organizations (includes 1 subscription to Journal de- posited under assumption it was for dues).................... 380.00 $609.07 1920] ALSBERG: REPORT OF SECRETARY-TREASURER THE YEAR ENDING NOVEMBER 21, 1917. Washington, D. C.), Secretary-Treasurer. 1916 Noy. Noy. aa 25 25 4 DISBURSEMENTS. Tips, New Willard Hotel, 1916 meeting.................. Telephone calls, New Willard Hotel, 1916 meeting......... 1000 special request 2-cent envelopes....................- POSUERE ia reel srsuci siege eh or ace ove: a oko otayn ingore (osore vel aueroics cievagey opeievs foe Stenographic report Tuesday afternoon meeting, November Pa UO ak, Ad aid ae oie pick oe Sia tec eee terete etter Grae Partial payment for editing Vol. II, No. 4 of the Journal (MV trrri all) Ee te care ete ee ee oe ice ot oS an Post office box rent for quarter ending March 31, 1917..... Rostagel (Journal): 2). ft ects cn ee cee tees ae [Eexpressagey(JOUrnAl) |.jie.e.sa: te isis iiterctenciste he tec sagen ears Printing circulars’: F555 casifewoctevays sis Oi a oslo nls. Sys8 Shoe alae us Printing 1000 letterheads (Journal)...................... POSH RON Ree ehere sist eiacecichale ca) oad creat stage elesarete Ona ueyetauaness Certified public accountant (Journal).................... Transferring post office box, increased rent due...... $0.36 bess ‘refand onikey ec a-reno Jota eS aie 0.20 Post office box rent for quarter ending June 30, 1917....... Printings! OOOMetterheadstem wr. ceie oelkya cess eae ia tans Refund to Williams & Wilkins Co. which was deposited under assumption it was dues (Journal)................ Editing remainder of Vol. II, No. 4 and part of Vol. III, INosltokthe: Journal QGournal) hess... oes ose Se 1000 special request 2—cent envelopes.............. $22.56 Less return on mutilated stamped envelopes...... 0.56 Post office box rent for quarter ending September 30, 1917. On account reporting Wednesday meeting, November 22, GTO = eR A Ras acide See Mais = Om igcbaleit a whasiedoets To complete payment reporting Wednesday meeting, INovember!22,6h90G Fc Aaes S2ee6-e64- 6 32.72 30.57 22.87 25.38 22.40 The carcasses from the 70 acre rotation pasture and the 50 acre pas- ture graded fair to medium, while the other three all graded good. The three carcasses were really as good beef as the average market would care to handle. These steers had had no grain whatsoever. They were typically range Angus steers. The quality of the meat was excellent. The close grazing of the range does not appear to affect the flavor of the meat. It is worth noting that the 30 acre pasture steer lost weight during the last ten days of August and on the reserve pasture from September first to October twentieth gained only 1.3 pounds per day, yet this steer dressed the highest per cent and showed the greatest per cent of fat in the cross section. This steer also had the greatest amount of offal fat, 23.5 pounds. The 50 acre pasture steer had only 10.5 pounds of offal fat. All the data on this steer indicate that the 50 acre pasture was exhausted and the steers were losing rapidly in condition while barely holding their own in weight. These steers were strictly grass steers. They did not know the taste of grain. The meat was produced entirely from products which man could not use as food and the meat thus produced was a definite increase in the nutrients available for man. I have tried to use these illustrations to show that in the economical production of man’s food the production and use of meat plays a very important part, because of the areas of our country that are only fit for the growing of grasses and because the production of cereal foods entails the production of nearly an equal weight of roughage in addition to the 30 per cent or more of milling by-products that are best suited for animal foods. To these should be added the protein concentrates from the seeds of flax, cotton, peanuts, soy beans, etc. Our experience of the past years has called to our mind the seriousness of a world shortage in food. We have increased our consumption of fish, but have scarcely begun to realize the possibilities of our waters to augment the meat supply. Our attention has been called to the possi- 1920] TROWBRIDGE: PRESIDENT’S ADDRESS 319 bilities of the utilization of animal flesh other than beef, pork, mutton, and poultry for food. Probably some here have tried the generous whale steaks. In the United States quite a number of markets have been established for the sale of horse meat for human food. They have met with very indifferent success, but there appears to be a growing demand for the cured horse meat for export. The horse does better than the steer on the open ranges in making a living under adverse conditions. He is able to graze closer and will paw away the snow in winter to get at the grass when a steer will starve. Horse meat is more like beef than it is like pork or mutton. In fact, most of us could not tell a roast of horse from one of beef. Our prejudice against eating an animal which has been of such service to man is hard to overcome. I hope the time may come when the meat of the horse will find its place on our tables without prejudice, yet I would not wish the stress of necessity to force us to it as was the case with Europe. There is not time to discuss the question of the economy of milk production or its importance as animal food. A steer may gain from 300 to 800 pounds in a year, not over 40 per cent of which is solids available for human food. In the same length of time the dairy cow may add 100 pounds to her weight and produce more than her body weight in milk solids. She exceeds the steer in economy of production, but she should be made to manufacture her products from those feed stuffs not already available for human consumption. Modern agriculture must not seek to make of man a vegetarian. Pro- duction and consumption of meat must be encouraged. Permanent agriculture demands crop rotation and the maintenance of soil fertility with the production of sufficient animals to manufacture into human food and into energy for man’s use those products not directly available to him. This should be done with a minimum use of that food for animals which is in its form adapted to man’s immediate use. As I try to figure the possibilities of meat production from the hay, grass, and roughage of the cereal crops, I am almost incredulous at the magnitude. I will not attempt to give you the figures. I have used the Government reports of acreage and yields. I have used Henry and Morrison’s! figures on the composition of the various roughages and on the digestible nutrients contained in them. I have estimated that one-half of all the cereal straw and corn fodder could be wasted and used for other than feed purposes. I have computed the number of cattle, sheep, horses, and mules and estimated that one-fourth of all the roughage should be reserved for the horses and mules. I have not counted in the feed value 1W. A. Henry and F. B. Morrison. Feeds and Feeding. 15th ed., 1915, 633-4. 320 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 2 of any of the concentrates nor the cereals. I have used our experimental data which show that only about 15 per cent of the digestible nutrients can be transformed by the animals into digestible meat product nutrients for man’s consumption. I have subtracted the over two and one-half billion pounds of meat and meat products we exported during 1918, and yet if we would only utilize what we already produce every man, woman, and child in our land might eat pork and poultry as of old and, in addition, have more than one and one-half pounds of beef or mutton every working day in the year. FIRST DAY. MONDAY—MORNING SESSION. The thirty-fifth annual convention of the Association of Official Agri- cultural Chemists was called to order by the President, P. F. Trowbridge, of Agricultural College, North Dakota, on the morning of November 17, 1919, at 10:00 at the New Willard, Washington, D. C. REPORT ON FOODS AND FEEDING STUFFS. By G. L. Bipwett (Bureau of Chemistry, Washington, D. C.), Referee. The referee has very little to report. He has consulted with his associate referees on several occasions, written letters regarding the work of the association, and given advice to a small extent. The investiga- tional work, however, has been conducted by the associate referees and their reports will speak for themselves. R. F. Jackson and C. L. Gillis (Bureau of Standards, Washington, D. C.) presented a paper on “The Double-Polarization Method for Estimation of Sucrose and the Evaluation of the Clerget Divisor”™'. REPORT ON SUGAR. By A. H. Bryan? (Arbuckle Bros., New York, N. Y.), Associate Referee. DISCUSSION OF FORMER ASSOCIATE REFEREE’S RECOMMENDATIONS. During the past two years it has been impossible for the associate referee to carry on any extended work upon the recommendations left over from the 1916 meeting, although many of these are of the greatest importance to chemists called upon for sugar determinations. The recommendations of C. A. Browne (New York Sugar Trade Laboratory, 80 South Street, New York, N. Y.), former associate referee, called for further study along the following lines?: (1) Upon the modifications proposed in 1916 for determining sucrose by acid and invertase inversion. 1U_S. Bur. Standards Scientific Paper 375: (1920). 2 Since deceased. 3 J. Assoc. Official Agr. Chemists, 1919, 3: 263. 321 322 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 (2) Upon methods for the determination of small amounts of reducing sugars in the presence of sucrose. (3) Upon the methods of determining copper by reduction of the oxid in alcoholic vapors. (4) Upon the optical methods for estimating raffinose in beet products, using enzyms for the hydrolysis. It is suggested that the first, second, and fourth recommendations be referred to the Carbohydrate Laboratory of the Bureau of Chemistry for study, as there is need in these recommendations for the continuous work of one man. The third recommendation could be studied by any chemist doing reducing sugar determinations, as it is a rapid method of determining the copper in the cuprous oxid precipitate from reducing sugar determinations. In the case of pure sugars, the weighing of the cuprous oxid gives good results, but with impure sugar products this method does not give true results, because of the contamination of the cuprous oxid with organic matter, and also with mineral salts. The changing of the cuprous oxid to cupric oxid by heating, or of the cuprous oxid to copper by alcoholic vapors, removes the organic matter, but does not remove the contamination by mineral salts. The most accurate method is to determine the copper in the precipitate volumetrically. At the 1916 meeting, W. D. Horne (National Sugar Refining Company, Yonkers, N. Y.) asked for an investigation and report upon five points’. Upon some of these a little work has been conducted, but on others there seems to be no particular need for experimentation. The following suggestions on the points submitted by Horne are made: (1) That raw sugar samples be mized in a mortar, instead of on a plate, to diminish moisture changes.—Under normal conditions there is little mois- ture change by mixing samples of raw sugar on a glass plate, and a more thorough mixing in a shorter time is accomplished on the glass plate than in the mortar. It was impossible for the associate referee to mix as many samples in a given length of time in a mortar as upon a glass plate. This, however, may have been due to awkwardness on his part, as he has always used the glass-plate method. Comparative experiments showed a greater tendency for wet sugars to cling to the mortar than to the glass plate, and more difficulty was noted in cleaning the mortar than the glass plate. With certain raw sugars, as Philippine mats and hard, lumpy, dry sugar, the mortar gave a sample more even in appear- ance than the same sample mixed upon a glass plate, using a rolling pin or spatula to mash the lumps. Polarization, however, revealed no decided difference in favor of the one or the other method of mixing. It 1 J. Assoc. Official Agr. Chemists, 1919, 3: 263. 1921] BRYAN: REPORT ON SUGAR 323 is believed, therefore, that raw sugar samples may be mixed on a glass plate or in a mortar, and yield as correct results one way as the other. (2) That the defecation be made with the minimum amount of lead sub- acetate requisite to cause flocculation and that an excessive quantity for pro- ducing a lighter-colored filtrate than is necessary to obtain a reliable reading be avoided.—All printed regulations for the use of lead subacetate require that a minimum amount be used, which means just enough lead to cause a clear defecation. All sugar chemists know that increasing the quantity of lead subacetate changes the polarization, especially in low-grade sugars, and it is to be regretted that an absolute amount of lead sub- acetate to be used with raw sugars of a definite polarization can not be prescribed. This point is covered in the methods of analysis. The term “minimum quantity” is really a personal equation. (3) That polarizations be checked by readings above and below rather than by averaging.—The usual method of polarizing sugars is to average a series of three to five successive readings. In each case the reading is the one in which the analyst believes he has an exact match of color in the field. The writer has been unable to obtain as concordant results by the method suggested as by the usual method. (4) That polarizations be made at 20°C., or that temperature corrections for levulose be included with those for sucrose-—The methods of the Inter- national Commission for Uniform Methods of Sugar Analysis! which were adopted by this association require that polarizations be made at 20°C., but they do not offer any corrections for polarizations made at other than 20°C. Corrections for temperature in polarizations should be founded upon the substance that is being polarized, that is, the temperature correction for a raw beet sugar is different from that for a raw cane sugar; hence they are not interchangeable. The application of a correction for sucrose alone where other sugars are present is also wrong. The question of temperature corrections for raw cane sugars is discussed on page 326.) (5) That the Bureau of Standards be asked to certify to the most advisable Baumé scale and that it be adopted.—The Baumé scale still clings in the ~ sugar industry. Yet Baumé spindles are not graduated as finely as those standardized for the Brix scale. The ordinary Baumé spindle is generally divided into degrees and seldom finer than half a degree, while the ordinary Brix spindle is divided to a tenth of a degree. With 1° Baumé equalling 1.8° Brix, it is easily seen that by using a Brix spindle a more correct reading of the density can be obtained than by using a Baumé scale. The Baumé scale should be relegated to the shelf, and only the Brix scale used. If there is real need for a Baumé scale, however, the one in general use should be that advocated by this association. 1 Proceedings, Paris Convention, 1900. 324 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 AN AMERICAN-MADE POLARISCOPE. During the past few years few, if any, polariscopes have been imported into this country; and of the few many showed big discrepancies in the scale. As the time seemed ripe for the production of an American polariscope, and makers were eager to produce it, it was decided to formulate specifications for a polariscope which would be accurate, simple, and easy of manipulation, and would embrace the best ideas of the users of these instruments. With this in view, C. A. Browne, after consultation with many sugar chemists, submitted to a committee of the American Chemical Society specifications for a polariscope. These were gone over very carefully and in the main approved. A sample instru- ment was built from these specifications and criticised by members of this committee. Two points of difference arose: Optical system and normal weight. Optical system.—The preference as to a polarizer was divided between the Lippich and Jellet-Cornu systems. The former consists of a large Nicol prism with a smaller Nicol prism (half-prism) covering just half of the field and placed in front of the large one. The two must be in exact alignment to obtain good results. In the Jellet-Cornu system there is only one prism. It is generally admitted that the Lippich system gives greater accuracy, and some held out for this, but it has the disad- vantage of being a little more complicated and more easily put out of order than the Jellet-Cornu. For factory work and the ordinary run of polariscopic work, the Jellet-Cornu system can not be said by any to give unreliable readings due to the lower degree of sensitiveness. This question of optical system has been left to the opinion of the buyers of the new polariscope. With a Lippich system, however, the price will probably be some fifty to one hundred dollars more than with the Jellet-Cornu system. Normal weight.—Upon this point decided opposition developed. With the start of a new polariscope many members of this committee thought it was time to adopt a rational normal weight. The German standard is 26 grams to 100 cc., and the French standard, 16.29 grams to 100 ce. Both of these figures are not easily divisible without a fraction, one of the reasons that a 20-gram standard should be the one adopted for the polariscope made in America, 20 grams being divisible by 2, 4, 5, 10, ete. In fact, any standard pipette will deliver an even number of grams of material when 20 grams are dissolved and made up to 100 cc. This proposed standard is also between the two present standards. It is also superior to the 26-gram, in that it will allow of a normal weight of dextrose and lactose. Obviously, this proposed 20-gram standard is of great advantage to the food chemist who takes aliquot parts of his solution used for polarization to make other determinations. It is also 1921) BRYAN: REPORT ON SUGAR 325 of great use in control work around sugar houses, both cane and beet, as well as in refineries. With the French standard of 16.29 there has been no objection to the smallness of the charge used for analysis, or inaccuracy in reading due to this small charge, nor have objections arisen to the use of the 26-gram standard because of inaccuracies of reading. This objection, however, has been raised in connection with the adoption of the proposed 20-gram standard. Another reason for adopting this new standard of 20 grams is that it is proposed to have it absolutely accurate. At present there are in use in this country polariscopes standardized for 26.048 grams in true cc., in Mohr ce., and for temperatures of 17.5° and 15°C., in addition to the late standard of 26 grams to 100 cc. at 20°C. Even this last standard for the polariscope has been found by Bates (Bureau of Standards, Washington, D. C.) to be incorrect. The 100° point on the scale reads only 99.895 when using 26.00 grams of pure sugar in 100 cc. and polar- izing at 20°C. The United States Treasury Department has adopted this new value in the valuation of raw sugar for duty purposes, and the Bureau of Standards uses it for standardizing quartz plates. This pro- cedure then adds another standard for the 26-gram instrument to the already numerous ones. E. Saillard of France has recently shown that the normal weight for the French instrument is not 16.29 but 16.26'. In view of these inaccuracies and the many standards for 26-gram instruments, the American polariscope should be made with a standard which is correct, and not open to error, and which is rational. The 20- gram standard will answer this purpose. The 20-gram standard is not new, for Sidersky and Pellet advocated the adoption of the normal weight of 20 grams as an international sugar scale at the Second International Congress of Applied Chemistry, held in Paris in 1896. This standard of 20 grams has been voted upon favorably by the Louisiana Sugar Chemists and the Hawaiian Sugar Chemists. Many English chemists have spoken favorably of it; and the French chemists are willing to accept it if it becomes international. It is the desire of all advocating this standard that the value for 20 grams be checked by the physical laboratories of all countries. A committee, composed of C. A. Browne, C. E. Coates (State Univer- sity, Baton Rouge, La.), and G. W. Rolfe (3 Dana street, Cambridge, Mass.), has been appointed by the American Chemical Society to get in touch with the various governments abroad with a view to arranging an international standard for the polariscope. It is the purpose of this committee to take up this matter with the various chemists in this country. It is suggested that a committee be appointed from this asso- ciation to look into the question of the adoption of this new 20-gram standard, if it can be made international. 1 J. fabr. sucre, 1919, 60: No. 13 326 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 STANDARDIZATION OF QUARTZ PLATES BY THE BUREAU OF STANDARDS. For the past year or so the Bureau of Standards has been standardizing the quartz plates sent them on the value found by Frederick Bates and R. F. Jackson of that Bureau, that the 100° point is low by 0.105°, and not on their former value which has had practical universal usage. A quartz plate with a German Reichsanstalt value of 99.895°V. would be certified by the Bureau of Standards as reading 100°V. The applica- tion of quartz plates with the new Bureau of Standards value to sac- charimeters equipped with Reichsanstalt scales may cause the intro- duction of serious errors. In making a reading upon a polariscope it is customary first to see that the zero point of the scale is in perfect adjustment. The standard quartz plate is then introduced and any deviation from the certified value employed as a correction in the readings. If the vernier of the polariscope be changed so that the scale reading agrees with the new plate, readings made in the vicinity of zero will be in error to the extent of 0.105 and invert readings in the vicinity of —30 will be in error to the extent of 0.14. These errors at various points of the scale may be con- siderably multiplied in case of diluted solutions. To avoid such dis- crepancies, polariscopes equipped with the Reichsanstalt scale should be controlled only by quartz plates standardized according to the Reich- sanstalt value, for only in this way is the scale correct at all its points. In other words, scales and control plates should be measured according to one and the same standard. Most sugar chemists who have gone into the subject are free to admit that the 100° point is low. There is grave doubt, however, whether it is as low as the Bureau of Standards makes it. The work upon which this value was founded has been severely criticised by sugar chemists abroad, and until it has been checked it is not advisable tomake changes in the old international value. It is much less advisable to apply this correction for the 100° point in the way the Bureau of Standards is doing. If there is an error in the 100° point, the only correct way is to increase the normal weight and use the old scale, or to change the gradua- tion of the scale so that the error will be distributed equally from 0 to 100. In view of these facts, it is most strongly recommended that when quartz plates are sent to the Bureau of Standards for certification they be requested to certify to the old value of the 100° point, and not their new one—at least until this new value has been agreed to internationally. TEMPERATURE CORRECTIONS FOR RAW CANE SUGARS. At the twenty-second annual meeting of this association in 19051, and again at greater length at the twenty-fifth meeting”, C. A. Browne called 1U_S. Bur. Chem. Bull. 99: (1906), 20. ? Ibid., 122: (1909), 221. 1921] BRYAN: REPORT ON SUGAR 327 attention to the temperature factor in polarizations of raw cane sugars. At the twenty-eighth meeting in 1911', W. D. Horne showed the effect of temperature correction on polarizations of raw cane sugar. Compara- tive results on the polarizations of raw cane sugars when polarized at 20°C., and when polarized at varying temperatures, but corrected by Browne’s temperature correction formula’, are here recorded. The gen- eral formula for correcting the polarizations (P) at t° of any raw cane sugar to P*°’ is as follows: p?? = pt + 0.0015 (Pt — 80) (t° — 20). The chart shown in Fig. 1 gives corrections for sugars polarizing from 80 to 97, and for temperatures from 21° to 35°C., based on this formula. eer ee reer ae z BA migiamlalsigiolcleieipiols lololed eee eee em en aes [aes Eee dl ce CRIDER actos mice Es oqo] | | tT | | fescg | | | foto asjo| | | | fosjos | | | foo) vo ajo] | | fog | | | Povo] | | bolas! Sarainae foo, _|_| | [eveler 8&8 8 POL A AZAAIT ION ee FIG. 1. CORRECTIONS FOR POLARIZATIONS MADE AT OTHER THAN 20°C. 1U. S. Bur. Chem. Bau ii sass Gen ), 207. 2 J. Ind. Eng. Chem 328 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 In this chart the corrections vary by 0.05°, as this is the lowest differ- ence most sugar chemists use for their polarizations. This chart has been in use by the writer for some five years in the polarizations of raw cane sugars. Table 1 gives the comparative results of 4,117 polarizations made in 1915, 1916, and 1917 at 20°, together with the polarizations made at ordinary room temperature and corrected by this chart. The polarizations at 20°C. are those of the New York Sugar Trade Labora- tory; the others are the associate referee’s at room temperature, with the corrections. TaBLe 1. Results of polarizations at 20°C., and at room temperature, with corrections. RESULTS WITH 20°C. POLARIZATION. PER CENT | Same or within 0.05°..............- 005-00 So higher. \ ei. aie sissies arse 0:05-0:15? lower nr. 32% << seye Rhe tere 0.15-0.25° higher O:15—0:252 lowert a. 6 58 2 0.25-0.35° higher O:25-0'8STlowerrs.8 sae eee Soe 0:35-0:45 a higher...ic.ccciaciscteesia Sei O:35=0:45 "lower sc seyc= te ce acct see O:45.up highec 22. saci svastora croc ® O45 upillowerssi2es. ease Salone ee SOSSHNIDITH me WOOTTON ERO During the year 1915, the average temperature-corrected polarization was 0.010° higher than that made at 20°, in 1916, 0.010° lower, and in 1917, 0.001° lower. These results indicate that the temperature correction formula pre- pared by C. A. Browne will give average results closely approximating the true polarization at 20°C. This formula can not be expected, how- ever, to give exact results in each case, due to the varying percentages of fructose and glucose in samples of raw sugar of the same polarizations. The adoption of this formula is recommended for use in correcting the polarizations of raw cane sugars when made at any temperature other than 20°C. It is recommended also that this formula should be substituted for the quite frequently used formula of P?” = Pt {1 + 0.0003 (t — 20)] which corrects only for sucrose, and gives too large corrections when applied to raw sugars containing sugars other than sucrose. RECOMMENDATIONS. It is reeommended— (1) That the following recommendations left over by the former associate referee be referred to the Carbohydrate Laboratory of the Bureau of Chemistry for study: 1921] BRYAN: REPORT ON SUGAR 329 (a) Further study upon the modification proposed in 1916 for deter- mining sucrose by acid and invertase inversion. (b) Further study for the determination of small amounts of reduc- ing sugars in the presence of sucrose. (c) Further study upon the optical methods of estimating raffinose . in beet products, using enzyms for the hydrolysis. (2) That the methods of determining copper by reduction of the oxid in alcoholic vapors be further studied. (3) That under the heading in the official methods, “Preparation of Sample.—Tentative.”” IX, Saccharine Products!, the following be added: (d) Raw sugars.—Mix thoroughly on a glass plate in the shortest possible time with spatula and glass or iron rolling pin in case of lumps, or in a large clean dry mortar. (4) That Browne’s temperature formula for correcting the polariza- tion of raw cane sugars to that of 20° be adopted: p? — Pt + 0.0015 (Pt — 80) (t° — 20) but where the percentage of levulose is actually determined, use the formula p?* = Pt + 0.0003°S (t — 20) — 0.00812°L (t — 20). (5) That the question of the adoption of the Baumé scale of the Bureau of Standards in place of the one now in use be further considered, possibly by a committee. (6) That where standard quartz plates for the German or Ventzke scale are sent for certification, the Bureau of Standards be requested to certify on the old value of 100°V. = 34.657° (circular degrees) for sodium light at 20°C. in place of their new value of 34.620° until this has been adopted internationally. (7) That a committee be appointed to get in touch with the committee of three appointed by the American Chemical Society, upon an interna- tional normal sugar weight, and also to ascertain the views of all members of this association upon the adoption of an international standard normal weight of 20 grams. l Assoc. Official Agr. Chemists, Methods. 1916, 121. 330 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 DENSIMETRIC AND POLARISCOPIC STANDARDIZATION IN REFERENCE TO THE ASSOCIATE REFEREE’S REPORT ON SUGAR. By Freperick Bares and R. F. Jackson (Bureau of Standards, Washington, D. C.). In view of the current situation relative to certain important scientific procedures in the sugar industry which are treated in the report of the associate referee on sugar, page 321, the writers desire to present the following comments: BAUME SCALE. W. D. Horne (National Sugar Refining Company, Yonkers, N. Y.), at the thirty-third annual convention of the association, asked for an investigation and report upon a number of points. Among them was the following!: “That the Bureau of Standards be asked to certify to the most advisable Baumé scale and that it be adopted’. Relative thereto, the associate referee advises as follows: ‘“‘The Baumé scale should be relegated to the shelf and only the Brix scale used. If there is real need for a Baumé scale, however, the one in general use should be that advocated by this association.” It so happened, that, simultaneously with Horne’s recommendation, the Bureau of Standards, in response to frequent requests, had been preparing a Baumé scale to meet the very situation which was responsi- ble for this recommendation’. It is unnecessary to enter into a discussion of the chaotic condition relative to the Baumé scale which existed prior to the advent of the Bureau of Standards scale. About twenty scales were in existence in various parts of the world, among which were two different scales pub- lished in the methods of this association*. None of these scales was based on accurate scientific data. The writers believe that it would be a step forward could the Baumé scale be abandoned. It is, however, still firmly entrenched, so far as practical use is concerned, and the only feasible plan which presented itself for its-elimination was to educate the users to the advantages to be obtained by using the so-called Brix scale. With that end in view, the Bureau of Standards scale gives in parallel columns the value of each degree Baumé in terms of Brix. It is probable that the use of this scale will gradually result in the elimination of the term Baumé. The new Baumé scale has three features which should render its adoption a matter of routine: 1 J. Assoc. Official Agr. Chemists, 1919, 3: 264. 2 U.S. Bur. Standards Technologic Paper 115: (1918). 3 Assoc. Official Agr. Chemists, Methods, 1916, 124; U.S. Bur. Chem. Bull. 107, rev.: 1910, 221. 1921] BATES-JACKSON: POLARISCOPIC STANDARDIZATION 331 (1) It is based upon the specific gravity values of Plato! which are considered the most reliable. (2) It is based on 20°C., the most convenient and widely accepted temperature for sugar work. (3) It is based on the modulus 145, which has already been adopted by the Manufacturing Chemists Association of the United States, by the Bureau of Standards, and by all American manufacturers of hydrometers. Since the issuance of the new scale, it has come into general use and all spindles submitted to the Bureau of Standards for general scientific and sugar work are standardized upon it. The writers would therefore recommend for your consideration the importance of the adoption of the new Bureau of Standards Baumé scale in accordance with the recommendation of Horne. It is felt that action upon this matter is of importance to this association and that the present unsatisfactory condition will continue indefinitely should the indefinite advice of the associate referee be adopted, namely, “If there is real need for a Baumé scale, however, the one in general use should be that advo- cated by this association”. NORMAL WEIGHT. The associate referee’s recommendations under this heading, page 324, constitute an argument in favor of changing the present international normal sugar weight of 26 grams to 20 grams. The suggested change emanated from conditions incidental to the war. It is perhaps unneces- sary to repeat the well-known fact that for many years the best efforts of the leading sugar chemists of the world, especially at the meetings of the International Sugar Commission, have been directed towards securing an international normal sugar weight. The importance of international agreement upon this weight is obviously of the utmost importance. In order to obtain the present normal weight of 26 grams, the old so-called German weight of 26.048 was abandoned by the International Sugar Commission in favor of 26 grams, and at the same time the standard temperature of 20°C. was adopted. The advantages which have accrued to the sugar industry throughout the world because of the international scale have been tremendous. The 26-gram weight was adopted by practically the entire civilized world, the one exception being France, the latter nation refusing to change its normal weight of 16.29 grams. It is now stated, upon whose authority it is not known, that the French chemists are willing to accept 20 grams, providing it is made interna- tional, but recently E. Saillard?, a French sugar chemist of international 1 Wiss. Abh. der Kaiserlichen Normal-Eichungs-Kommission, 1900, 2: 153. 2 J. fabr. sucre, 1919, 60: No. 13. 332 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 reputation, has published an article in which he opposes both the 20- and 26-gram normal weight in favor of 16.29 grams. The inconvenience to the sugar industry of practically the entire world would be very great, indeed, should such a radical change be adopted in the normal weight as that advocated by the associate referee. It is believed that the sugar companies would continue to use the present international normal weight. The associate referee states that a committee has been appointed by the American Chemical Society to get in touch with the various govern- ments abroad with a view to arranging an international standard for the polariscope. The writers believe that the associate referee is somewhat in error in this statement in that this committee was appointed merely to make inquiries as to whether certain European nations, especially Eng- land and France, would be willing to adopt a 20-gram normal weight. The writers do not believe that the American Chemical Society has dele- gated authority to any committee to get in touch with the various gov- ernments abroad with a view to arranging an international standard for the polariscope. The associate referee’s suggestion that a committee be appointed from this association to get in touch with the committee from the American Chemical Society and with the members of this association on the question of the adoption of the new 20-gram standard, providing it can be made international, is practically equivalent to committing this association to the adoption of the 20-gram weight, and the writers wish to protest against committing this association in any such manner. STANDARDIZATION OF QUARTZ PLATES BY THE BUREAU OF STANDARDS. The associate referee asserts, page 326, that the application of the new Bureau of Standards value of quartz plates may cause the introduction of scale errors. This conclusion results from a misconception of the proper method of applying corrections. He suggests two methods of correcting for scale errors. In the first, he adjusts the zero at zero and then determines the deviation of the scale from the certified value of the plate to obtain the correction. If this correction is applied proportion- ately to the observed rotation, no discrepancy can result. There is therefore no error to be multiplied. In the second method, he adjusts the instrument at the 100° point to accord with the certified value of the plate. He then concludes that readings in the vicinity of zero will be in error by 0.105 and at —30 by 0.14. In other words, he advocates the curious procedure of determining the scale errors by means of a certified plate and then deliberately | 1921) BATES-JACKSON: POLARISCOPIC STANDARDIZATION 333 neglecting to apply the corrections thus ascertained. He further con- cludes that polariscopes equipped with a Reichsanstalt scale should be controlled by the incorrect Reichsanstalt standard in order that the plates shall agree with the instrument scales. In answer to this, we submit the obvious fact that the control plate should be used to stand- ardize the scale and not the reverse. The associate referee further remarks that most sugar chemists who have gone into the subject are free to admit that the 100° point is low, but there is grave doubt whether it is as low as the Bureau of Standards makes it. The latter part of this assertion is evidently based upon his further statement that ‘““The work upon which this value was founded has been severely criticised by sugar chemists abroad’. The writers wish to enter a solemn protest against any such misstatement of facts. So far as our information goes, there has only been one statement which could be construed as a criticism of the work of the Bureau of Standards in determining the 100° point of the saccharimeter. The criticism referred to is a statement by A. Herzfeld! (Institut fiir Zuckerindustrie, Amrum- strasse, Berlin, N. 65, Germany), who was the joint collaborator of Otto Schénrock (Physikalisch-Technische Reichsanstalt, Berlin, N. W., Ger- many) in determining the previously accepted value of the 100° point. The so-called criticism is approximately 150 words in length and is confined to a short discussion of several minor points involved in the preparation of the sugar used by the Bureau of Standards. Herzfeld merely conveys the idea of a possibility of the existence of a slight error due to these causes. He does not furnish the slightest proof that any error was made. On the contrary, all measurements and all contributory data developed since the determination of the constant by the Bureau of Standards have merely served to verify the correctness of the new value. Fortunately, or unfortunately, depending upon the point of view taken, the correction of the error in the old value of the 100° point operates in favor of the producers of sugar and against the buyers of sugar. For many years the buyers of raw sugars have had the advantage of a lowering of the test of over 0.°1S. In view of these facts, the writers desire to advise against the adoption by this association of the associate referee’s recommendation that mem- bers sending quartz plates to the Bureau of Standards for standardiza- tion request that the Bureau of Standards certify on the old value of the 100° point in place of the present corrected value until this has been adopted internationally. 1Z. Ver. Zuckerind., 1917, 67: 407. 334 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 THE ATTITUDE OF THE NEW YORK SUGAR TRADE UPON THE NEW BUREAU OF STANDARDS VALUE FOR STANDARDIZING SACCHARIMETERS|! By C. A. Browne (New York Sugar Trade Laboratory, New York, ING Yo) The question of the standardization value of normal quartz plates for saccharimeters, which A. H. Bryan discusses in his report, page 326, is a matter of extreme importance, as the difference of 0.1 sugar degree between the official standards of Berlin and Washington will mean a difference of over one million dollars in the valuation of sugars handled by the New York Sugar Trade. This conflict of opposing standards has already caused some uneasiness in the trade, and the matter has been carefully considered by the Directors of the New York Sugar Trade Laboratory, who represent equally the buyers and sellers of raw sugar. The standard of graduation for the German or Ventzke scale which has been employed by the New York Sugar Trade up to the present time is the one which is being used by practically all members of the International Commission for Uniform Methods of Sugar Analysis, the methods of which are the official methods of the New York Sugar Trade. The Directors of the New York Sugar Trade Laboratory, after careful consideration of the question, voted unanimously against the adoption of the new Bureau of Standards value for standardizing sac- charimeters for the following reasons: (1) That the new Bureau of Standards value has been criticised by European investigators and until it has been confirmed by testing bureaus in other countries and has been agreed to internationally it would be exceedingly unwise to adopt a value which might have to be changed again to something else. The Directors of the New York Sugar Trade Laboratory do not wish to make any departure in methods or standards unless the proposed changes have a fair prospect of perma- nency, especially in international transactions, otherwise the sugar trade will be subjected continually to disturbances of this kind. (2) Granting that there may be a slight error in the present German standard, and even granting that the new Bureau of Standards value may be correct, the Directors of the New York Sugar Trade Laboratory are of the opinion that no injustice is being done at present to the sellers of raw sugar for the reason that the minus error due to scale graduation is offset by an equal or greater error due to the volume of the lead precipitate in clarification. 1 Presented by G. L. Bidwell. 1921) HORNE: COMMENTS ON RECOMMENDATIONS 335 If a scale error exists it should by all means be corrected, and the true standardization value fixed by international agreement. When this scale error is corrected, the counter-balancing lead precipitate error should also be corrected either by dry lead defecation, as proposed by W. D. Horne, or by other accurate means. I might say in conclusion that this decision of the Directors of the New York Sugar Trade Laboratory is in complete agreement with the opinion of Prinsen Geerligs of Holland and other European authorities. COMMENTS ON RECOMMENDATIONS PROPOSED BY A. H. BRYAN. By W. D. Horne (National Sugar Refining Company, Yonkers, N. Y.). The following comments are presented relative to recommendations 3, 4, 5, and 6 of the associate referee on sugar, page 329: (3) In mixing sugar samples, particular care should be taken to avoid excessive exposure to the air. Speed is of first importance. Avoidance of exposure of thin layers of sugar to the air may be helped by mixing in a mortar instead of on a plate. (4) In cases where the invert sugar is known, more accurate results for individual samples may be obtained by using the formula p20° = Pt + 0.0003°S (t — 20) — 0.00812°L (t — 20) where S = sucrose and L = levulose (one-half the invert sugar). (5) The Baumé scale is so thoroughly entrenched in the industries that it will continue to be used and must be taken into consideration. The Bureau of Standards new scale and table is of particular value, having the modulus 145, which is close to the averages heretofore in use, is a round number and has already been accepted by the Manu- facturing Chemists Association. The reference of sugar solutions at 20°C. to water at 20°C. is also a great advantage. (6) The Bureau of Standards work on the 100° point of the polariscope was conducted with the utmost precaution and the one criticism of it is merely a suggestion that some inversion of the pure sucrose may have occurred. No evidence of such inversion is given, however, and it is not at all probable that it occurs, since the sugar solutions used never were heated above 35°C. The government will doubtless continue to employ the corrective value and it is important that all remaining errors of polarization, especially elevation due to the volume of the lead precipitate, be elimi- nated as soon as possible. 336 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 A SUGGESTED MODIFICATION OF THE METHOD FOR CRUDE FIBER?. By L. D. Hateu (University of Missouri, Columbia, Mo.), Associate Referee on Crude Fiber in Foods and Feeding Stuffs. The study of the crude fiber determination this year has centered around the filtration operations. The treatment of feeds with dilute acid and alkali produces solutions which do not pass easily through ordinary filtering media. This has led to the use of muslin or linen as filtering media. The uncertainty that the cloth holds all the fine particles of fiber and the fact that no two chemists would be likely to use the same variety of cloth in filtering, renders this mode of filtering undesirable. Because of these reasons, the writer has preferred the one filtration method since it avoids one of these doubtful operations. The associate referee has been unable to find a quick filtering medium which could be substituted for the muslin or linen cloth. The feeds most difficult to filter in the crude fiber determination are those of high protein content, such as linseed and cottonseed meal. If the protein in the feed could be dissolved without producing a colloidal solution and removed before the acid treatment, the filtration could be conducted without difficulty, using asbestos, thereby avoiding loss of fine material. To test this, experiments were conducted with various proteolytic enzyms. The best results were obtained with pepsin. It is, therefore, suggested that a preliminary treatment with pepsin be made in order to render the protein soluble. It may then be separated from the undis- solved material by filtration through asbestos. Subsequent treatment of the residue with 1.25 per cent acid and alkali will not produce solu- tions which are difficult to filter, such as are obtained with the old procedure. The cloth filtration can then be abandoned and a filtering medium used, such as asbestos, which is more certain to retain all the insoluble material. The time lost in trying to filter the colloidal solutions from the regular method is largely saved, even though another step, which adds about 40 minutes’ work to the process, is introduced. The results should be entirely comparable with those obtained by the old method and have the additional advantage of greater accuracy. INSTRUCTIONS TO COLLABORATORS. Two samples were prepared—silage and cottonseed meal. Both sam- ples had been washed with ether and brought to a stable, air-dry condi- tion before they were distributed. The collaborators were asked to run 1 Presented by C. R. Moulton. 1921] HAIGH: CRUDE FIBER DETERMINATION 337 each of these samples as follows: (1) By the regular official method; (2) by the regular official method, preceded by a preliminary digestion at 40°C. for 30 minutes, with pepsin in the presence of dilute hydro- chlorie acid, after which the residue should be filtered, using an asbestos filter; (3) by the one filtration method, preceded by the above-mentioned digestion with pepsin; (4) in addition to the above, the acid filtrate from Method 2 was carried through the one filtration method to deter- mine how much material precipitated from this acid solution by the alkali digestion remains to contribute to the result on crude fiber. Some wide variations are observed in the results of the nine collabora- tors with the method using pepsin. The results, especially with the cottonseed meal, indicate to some extent a lack of uniformity in the samples. A uniform mixture of the ingredients of cottonseed meal is difficult to make and maintain. However, every reasonable effort was made to avoid this error. A further experiment conducted in the writer’s laboratory by W. S. Ritchie and T. H. Hopper is shown in the table as Method 5. It was thought possible that the hydrochloric acid washing of the residue could be omitted in the one filtration method when the preliminary digestion with pepsin was made. Two of the collaborators reported that the solutions were difficult to filter where pepsin had been used. This variation may be due to some collaborators having used pepsin, which was weak or utterly useless. The writer believes that in the removal of the protein from the feed before the digestion with acid, can be found the solution of the errors of the crude fiber method. RECOMMENDATION. It is recommended— That Method 2 receive further study and that suggestions and criticism be solicited. 338 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 Loss on ignition (crude fiber) in sample of ether-washed silage. ANALYST METHOD 1 | METHOD 2 | METHOD 3 | METHOD 4 | METHOD 5 per cent per cent per cent per cent per cent L. D. Haigh, W. S. Ritchie and 18.55 17.80 0.10 17.91 18.41 T. H. Hopper, University of | 18.35 17.95 0.13 18.32 18.47 Missouri, Columbia, Mo. 45 17.88 0.12 18.12 18.44 Average thc ic Rie. see eens 18 A. E. Smoll, Jacob Dold Packing 17.12 17.26 0.62 19.28 Company, Wichita, Kans. 17.23 17.27 0.46 19.55 Averageet acosarnte sxe rune 17.18 17.27 0.54 19.42 F. N. Smalley, Southern Cotton Oil | 17.07 16.51 0.225 17.18 Co., Savannah, Ga. 18.04 16.25 0.235 17.18 17.69 ese mete nee ANGQAGE. 5 0c cients. ce ier 17.60 16.38 0.23 17.18 J. M. Pickel, Department of Agri- 17.78 culture, Raleigh, N. C. 18.01 AVCLARE {326 ote es eee 17.90 He ee) ea S. H. Wilson and J. F. King, Depart-| 16.00 17.40 0.40 17.03 ment of Agriculture, Atlanta, Ga. 16.15 17.30 0.37 Pee IAW rage rate cn seat en alesaer 16.08 17.35 0.39 17.03 W. D. Richardson, Swift and Co., VAP 17.72 0.23 17.88 Chicago, Ill. 17.50 17.85 0.21 17.87 aWa6 Feo 0.18 17.83 AV CLARE? 22y.. RVR Gane aoe 17.61 17.79 0.21 17.86 W. F. Hand and L. B. Sandiford, | 16.24 17.36 0.57 16.10 Agricultural and Mechanical Col- | 17.06 16.55 0.06 17.76 lege, Agricultural College, Miss. | 17.70 16.91 0.12 17.00 AV CTO 6 oaks ashasiemeacttaciio vee 17.00 17.04 0.25 16.95 G. L. Bidwell and L. E. Bopst, Bu- reau of Chemistry, Washington, DG: sAverages ee ee 17.67 17.34 0 H. B. McDonnell and L. H. Van 16.70 17.65 0.15 Wormer, Agricultural Experiment | 17.05 17.55 0 Station, College Park, Md. Average sas/sctiec ere eee rs 16.88 17.60 0.14 17.29 ee 1921) HAIGH: CRUDE FIBER DETERMINATION Loss on ignition (crude fiber) in sample of ether-washed cottonseed meal. ANALYST L. D. Haigh, W. S. Ritchie and T. H. Hopper PAWETAL Gira sie... cia tysichelciesate'sis, cit PeeIN-SMANEY 05 = fot cle icles ee 15% L\WERN 5 ob Sao oe ao OaboRodaoT dU, Wily PAG Gllig 6 goobeoevagcuo oped. LAMERNTDs So Oca doco ueeoorade S. H. Wilson and J. F. King....... LAGE Sob, Sela p SOU CEES Gaetoe Wistie FEvIGhargson’,...o i: scene oon os PAV ELAR CR. ferstart: -yectsl - as 5 0.10 0.000036 Dilute ENE beets payeusiere ors 0.10 0.000036 Acid, trichloracetic. ....... 0.50 0.00018 NH,Cl: Ammonium carbonate...... 0.50 0.00026 Ammonium nitrate........| 1.00 0.00052 Ammonium oxalate........ 0.10 0.000052 Ammonium sulphate... .... 1.00 0.00052 BaCl,+2H.20: Barium hydroxid.......... 0.50 0.00062 Barium nitrate. ........... 0.10 0.000122 CaClk+2H,0: Calcium bromid........... 2.00 -00075 Calcium glycerophosphate..| 1.50 Tae Chloral hydrate........... 1.00 0.00036 @hlorofonmrss 2 nee ee 0.10 0.000035 Codein phosphate. ........ 0.10 0.000036 Codein sulphate........... 0.10 0.000036 Ethylchlonds hoe ooo 1.00 0.00036 Ethyl carbamate .......... 0.50 0.00018 FeCl; +6H,0 Ferric ammonium sulphate .| 2.00 wea Hexamethylenamin........ 0.50 aN 0.00016 Todin/... Seen Pee te 0.50 0.000175 LiCl: Lithium bromid........... 1.25 0.000105 * Dissolve in U.S. P. alcohol instead of water. . 7 Shake with 22 cc. of water in a separatory funnel, allow to separate, withdraw the water, and proceed by Method 1 from acidulation. SSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 MAXIMUM IMPURITY PERMITTED, CALCULATED AS per cent HCl: 0.0072 0.0072 0.0012 0.0022 0.036 0.072 0.036 0.072 0.0144 0.0434 0.0061 0.0144 0.0020 0.0014 0.0144 0.00288 0.0152 NH,Cl: 0.0208 0.0208 0.0052 0.0208 BaCl.+2H.20: 0.124 0.01 CaCl.+2H:;0: 0.30 grams See it BH Oo Me GS oon v ie Nie Pe wo ww wo on or Oro 0.10 t Pass gas through 22 ce. of N/10 nitric acid and proceed by Method 1 from dilution to 24 cc. VOLUME ° SAMPLE 9 + = , DINe 10 roNNosco: Few eee Coeds Nth Gory tron: ocr boop: SENS) te or Orc ot: ee Gus: ls - METHOD OF PREPA- RATION RR HIRE WW NNR eee OD _ * TIME LIMIT minutes Cre COTO ON OT Or Orr Or Or Or Or Or Or Or (SS) es nS ee a 1921] CHEMICAL Paraldelyde® 5. 2-2.c6.s ai: Pilocarpin nitrate......... Potassium chromate....... Potassium dichromate. . Potassium nitrate.......... Quinin salicylate. ......... Quinin tannate............ Sodium bicarbonate........ Sodium cacodylate......... Sodium oxalate............ MAXIMUM AMOUNT oF N/100 HYDRO- CHLORIC ACID PERMITTED IN STANDARD COMPARI- SON TUBE ce. 0.10 0.50 TasBLe 1.—Concluded. KEBLER: ESTIMATING LIMITS OF CHLORIDS IN CHEMICALS 363 EQUIVALENT MAXIMUM MAXIMUM IMPURITY WEIGHT OF IMPURITY PERMITTED, PERMITTED CALCULATED AS gram per cent MgCl.+6H,20: MgCl.+6H,0: 0.00103 0.082 (Ole Cl: OO TO Siete MS We eerste OLOOOL T5291 he Peet: HCl: HCl: 0.00009 0.0036 Pilocarpin HCl Pilocarpin HCl 0.00244 0.198 KCl: KCl: 0.00074 0.0059 0.00074 0.0089 0.00037 0.03 Quinin HCI+ Quinin HCI+ 2H.0: 2H,0: 0.00198 0.396 0.00594 2.37 HCl: HCl: 0.00036 0.072 NaCl: NaCl: 0.000216 0.0216 0.00116 0.232 0.00016 0.0232 SrCl,+2H,0 SrCl,+2H,0: 0.00266 0.53 HCl: HCl: 0.00036 0.07 0.00009 0.0036 0.00036 0.07 Gl: Gl: 0.000035 0.00015 ZnCl, : ZnCh: 0.00034 0.034 WEIGHT|VOLUME| OF OF SAMPLE] SAMPLE grams cc. 1.25 2000 2000 2.5 He 1.25 0.835 1.25 0.5 0.25 0.50 ; | 1.0 0.5 0.5 0.5 0.5 2.5 5 23 1 PREPA- RATION TIME LIMIT minutes Grover Or or cror o — me oroTror Or orm oO or ororcr t Pass gas through 22 cc. of N/10 nitric acid and proceed by Method 1 from dilution to 24 cc. § Heat to 50°C. just before adding the silver nitrate. method, because of different physical properties, different reactions, and different characters of the precipitates produced. Methods have been worked out for a number of chemicals, in the case of chlorids, to meet these features. The methods tested are as follows: (1) Dissolve the prescribed weight of chemical in about 15 cc. of water, acidulate with dilute (10%) nitric acid, add enough water to make exactly 24 cc., then add 1 ce. of N/10 silver nitrate solution, and mix thoroughly. (2) Mix the chemical to be tested with chlorid-free calcium carbonate in water, dry, and ignite. After cooling, add about 15 cc. of water and enough nitric acid to render slightly acid, dilute to 24 cc. with water, then add 1 cc. of N/10 silver nitrate solution, and mix well. 364 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 (3) Mix or dissolve the sample in a mixture of 25 cc. of water and 5 cc. of dilute nitric acid, and add enough silver nitrate solution to completely precipitate all of the halogens present. Filter, and wash the precipitate with water, rejecting the filtrate and washings. Digest the precipitate for 10 minutes with 5 cc. of ammonium carbonate, U.S. P. test solution, cool, filter, and wash with 15 cc. of water. Collect the filtrate and washings in a comparison tube, acidify with concentrated nitric acid, add water to make 25 ce., mix well, and compare with the standard. (4) Add about 15 cc. of water to the chemical to be tested and 1 cc. of dilute (10%) nitric acid, warm, shake, filter, and wash with enough water to make 24 cc. Add 1 cc. of N/10 silver nitrate solution and mix well. (5) Proceed as for Method 1, except that the standard must contain an equivalent amount of the chlorid-free salt to be tested. Place the prepared standards and unknown solutions in Nessler tubes. When ready to make the observation, add the N/10 silver nitrate solution simultaneously to the standard and the unknown solution, with thorough mixing. RECOMMENDATIONS. It is recommended— (1) That immediate steps be taken to study methods for testing chemical reagents in order to provide definite details that will minimize the personal equations now obtaining. (2) That steps be taken at an early date looking towards the publica- tion of a compendium of methods for testing chemical reagents. (3) That, if this association is not in position to undertake this task, this recommendation be transmitted to the Council of the American Chemical Society for consideration and action. No report on microanalytical methods was made by the referee. The appointment of the following committees was announced by the president: Committee on auditing: G. L. Bidwell of Washington, D. C.; W. F. Hand of Mississippi; and E. M. Bailey of Connecticut. Committee on nominations: A. J. Patten of Michigan; J. M. Bartlett of Maine; and B. L. Hartwell of Rhode Island. Committee on resolutions: W. D. Collins of Washington, D. C.; H. B. McDonnell of Maryland; and Julius Hortvet of Minnesota. The meeting adjourned at 12 m. to reconvene at 2 p. m. FIRST DAY. MONDAY—AFTERNOON SESSION. The president announced the appointment of the following committee to consider the Baumé scale and report not later than Wednesday morning: W. D. Horne of New York; Frederick Bates of Washington, D. C.; Paul Rudnick of Illinois; E. W. Magruder of Virginia; and R. E. Doolittle of Illinois. No referee on the subject of phosphoric acid was appointed and no report on this subject was presented. No associate referee on basic slag, to cooperate with the committee on vegetation tests on the availability of phosphoric acid in basic slag, was appointed and no report on this subject was presented. No report was presented by the committee on vegetation tests on the availability of phosphoric acid in basic slag. REPORT ON NITROGEN. By I. K. Puetps (Bureau of Chemistry, Washington, D. C.), Referee. In the investigation of the Dupont nitrometer for the determination of nitrate nitrogen, but two collaborators were obtained. This has been due to the exigencies of the war and the high pressure under which the laboratories which were supplied with Dupont nitrometers have been subjected and to the fact that most of the laboratories which are accus- tomed to collaborate with the referee are not supplied with Dupont nitrometers. It is believed, however, that with the return to normal conditions collaborators can be procured. It is, therefore, recommended that this subject be continued for further investigation. 365 366 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 REPORT ON SPECIAL STUDY OF THE KJELDAHL METHOD!. By H. W. Daupr (Jackson Laboratory, E. I. du Pont de Nemours & Co., Wilmington, Del.), Associate Referee. On account of war activities, no work on the collaborative study of the Kjeldahl method was accomplished last year. Although the collab- orators for 1918 were only required to take up during 1919 the work previously requested and to report the results of their work in time for the 1919 meeting, only three complete reports on the work submitted in 1918 have been received. The work herein reported is largely a continuation of the investiga- tions which had been made by I. K. Phelps and the writer. In fact, it is this study of the effect of the proportions and variations of reagents, and of time on the hydrolysis of difficultly decomposable substances, that has been made the subject of collaborative work. In addition, the retention of ammonia in the presence of mercury and copper salts during the distillation has been studied. The retention of part of the ammonia as a mercuric amino compound, when it is attempted to quantitatively distil ammonia from an alkaline solution in the presence of mercuric salts, was early recognized by H. Wilfarth?, who used alkali sulphids to remove the mercury as sulphid before making the distilla- tion. This work has been checked repeatedly by various investigators, including the associate referee, and the necessity of adding a reagent to remove the mercury has been so emphasized that further work along this line was deemed unnecessary. Because of the high cost of potassium sulphid and the difficulty in obtaining suitable material on the market, it appeared desirable to attempt to substitute this reagent by the cheaper and more easily procurable sodium thiosulphate. The experiments out- lined in the following directions were, therefore, planned: THE EFFICACY OF SODIUM THIOSULPHATE IN THE PRECIPITATION OF MERCURY. Dissolve exactly 5 grams of the ammonium sulphate in water and dilute the solution to 500 cc. (preserve the remainder of the solution for experiments with copper sulphate). After thoroughly mixing, pipette 20 cc. portions of this solution into 500 cc. Kjeldahl flasks. Add 300 cc. of water and an acid solution of mercuric sulphate obtained by dissolving 0.7 gram of mercuric oxid in a mixture of 15 cc. of water and 15 ce. of sul- phuric acid. Then proceed as follows: (a) Add 25 cc. of a 4% potassium sulphid solution, agitate, then add 70 cc. of a saturated solution of sodium hydroxid. After connecting the flask to the condensing 1 Presented by I. K. Phelps. 2 Chem. Zentr., 1885, 16: 17, 113. 1921] DAUDT: STUDY OF THE KJELDAHL METHOD 367 apparatus, agitate and distil into standard acid in the usual manner until 200 cc. of the distillate have been collected. (b) Add 25 ce. of an 8% solution of sodium thiosulphate, agitate, then add 20 ce. of a saturated solution of sodium hydroxid. Proceed as in (a). (c) Proceed as in (6) except that 12.5 cc. of 8% sodium thiosulphate solution are used. (d) Add 20 ce. of sodium hydroxid solution so that it forms a separate layer in the bottom of the flask. Then add 2 grams of sodium thiosulphate crystals. After con- necting the flask to the condensing apparatus mix thoroughly by agitation and distil in the usual manner. It is essential that blank determinations be made on the sulphid and thiosulphate and corrections made therefor. Make all determinations in duplicate. The addition of thiosulphate was made in the two ways mentioned above in order to determine whether or not any sulphur dioxid passed into the condenser before neutralization of all of the acid solution. TaBLe 1. Efficacy of sodium thiosulphate in the precipitation of mercury. PRECIPITANT* S . 2 grams of lg f 2g f wwe | rae | at | aba | mae (a) (6) “O e gram gram gram gram J. J. Vollertsen, Morris & Co., 0.04252 0.04252 0.04244 0.04252 Chicago, III. Paul Rudnick and N. A. Gray, 0.0420 0.0416 0.0423 0.0422 Armour & Co., Chicago, Ill. W. D. Richardson, Swift & Co., 0.04205 0.04122 0.04194 0.04202 Chicago, Ill * Average of duplicate results reported. The results of all of the collaborators indicate that potassium sulphid can be replaced by sodium thiosulphate, that the quantity necessary for complete precipitation of 0.7 gram of mercury (as sulphid) is 1 gram and that the manner of adding the reagent has no influence on the results. THE RETENTION OF AMMONIA BY COPPER SULPHATE. It seemed desirable to make a study of the effect of copper sulphate on the distillation of ammonia, both in the presence of a slight excess of sodium hydroxid and in the presence of a larger excess. The direc- tions sent to the collaborators for this part of the work were as follows: Pipette 20 cc. portions of the ammonium sulphate solution used in the experiments in which the efficacy of sodium thiosulphate was studied, into 500 cc. Kjeldahl flasks. 368 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 To each portion add the amounts of copper sulphate crystals and the amount of satu- rated sodium hydroxid solution indicated in Table 2, then add 300 cc. of water. Distil 200 ec. of the solution in the usual manner into standard acid solution. The results are given in Table 2. TABLE 2. Retention of ammonia in the presence of copper sulphate*. COPPER a NITROGEN ANALYST SULPHATE SODIUM FOUND HYDROXID gram ce. gram JJ. Vollextsenis co, i-cyaysteiase cy cece couse 0.0 2.0 0.04235 0.0 30.0 0.04235 0.5 2.0 0.04235 0.5 30.0 0.04235 1.0 2.0 0.04194 1.0 30.0 0.04194 Paul Rudnick and N. A. Gray.............. 0.0 2.0 0.0420 0.0 30.0 0.0423 0.5 2.0 0.0421 0.5 30.0 0.0420 1.0 2.0 0.0420 1.0 30.0 0.0422 We D> Richardsone.-- 2-2 Sanit 0.0 2.0 0.04073 0.0 30.0 0.04234 0.5 2.0 0.04083 0.5 30.0 0.04117 1.0 2.0 0.04120 1.0 30.0 0.04214 * Average of duplicate results reported. There is apparently a slight discrepancy in some of the results, but the conclusion can be drawn from the results of all of the collaborators that copper sulphate, in amounts of 0.5 gram or less, does not cause the retention of ammonia. For the study of the effect of the proportion of the reagents, sulphuric acid, alkali sulphate, and heavy metal catalyst, and of time of digestion, the following directions were sent out, together with the required samples: STUDY OF THE HYDROLYSIS OF REFRACTORY COMPOUNDS AND SUBSTANCES. Into 500 cc. Kjeldahl flasks introduce the weights of the compounds indicated in Tables 3 and 4. Add the reagents indicated and boil briskly. The flasks should rest in a perforation 2} inches in diameter. In the experiments in Table 4, where 0.2 gram of mercuric oxid is used, it is essential to drive off the hydrochloric acid from the pytidin zinc chlorid and from the nicotin zinc chlorid by first heating the weighed flask containing all of the sulphuric acid and then replacing carefully the sulphuric acid lost by volatilization. When the products of hydrolysis have cooled to room tempera- ture, add enough water so that, after the addition of 35 cc. of 4% potassium sulphid 1921] DAUDT: STUDY OF THE KJELDAHL METHOD 369 TABLE 3. Study of the hydrolysis of certain refractory substances*. CATALYST hac —— =p —_—— ——— NITROGEN eis |sunpHaTe|SC-PHATE| Mercuric | Copper lieaty See seo oxid | sulphate | | I | grams grams gram gram hours | percent | per cent Je -avollertsens....c2-)- + 10 ts 0.2 ace 2 7.40 2.46 10 sare 0.7 aie 13 =| 7.40 2.54 10 88 0.7 ae 2 | 7.44 2.63 mie 8.2 | 0.7 Ot 13 | 7.48 2.54 82 | 0.7 ie 2 7.56 2.63 10.0 0.7 oe 13 7.56 2.71 10.0 0.7 oe 2 7.48 2.67 10.0 a 0.5 13 7.36 2.13 10.0 0.5 2 7.44 PHY W. D. Richardson. ...... 10 Ae 0.2 Aiea i Noe Z | 6.978 | 2.083 10 are 0.7 ee 2% | 6.992 2.115 10 bests 0.7 ee 2 7.002 - | 2.168 = 8.2 0.7 ae 13 7.083 | 2.098 8.2 0.7 ae 2 7.097 | 2.217 10.0 0.7 ne 13 7.094 | 2.141 10.0 0.7 a2 2 7.080 | 2.195 10.0 aS: 0.5 ies 6.999 | 1.996 10.0 see 2 7.013 | 2.075 Paul Rudnick........... 10 se 0.19 ae 2 7.07 2.19 10 sere 0.65 ee 13 7.08 2.09 10 os 0.65 Hee 2 7.08 Ane se 8.2 0.65 ee 13 7.08 2.11 8.2 0.65 As 2 7.17 2.18 10.0 0.65 sx 1 6 4-12 2.22 10.0 0.65 te 2 7.15 2.25 10.0 Shs 0.5 13 7.09 1.96 10.0 0.5 2 7.00 2.02 10.0 0.5 2 7.02 Sah * Digestion was made with 25 cc. of sulphuric acid in all cases. ¢ One gram of material used. solution and later the required amount of sodium hydroxid solution, the total volume becomes about 375 cc. Distil in the usual manner into standard acid solution. (It is suggested that sodium alizarin sulphonate be used as the indicator.) The effect of varying reagents and time is more pronounced with compounds containing nitrogen in the ring, as for example with pyridin, nicotin and hyroxyquinolin, than with protein-containing substances such as soy bean meal. Pepper, being a piperidin derivative, falls into the first-mentioned class. It is apparent that difficulty has been found on the part of the col- laborators in hydrolyzing completely the most refractory compounds, pyridin, nicotin, and hydroxyquinolin. This is probably caused by a difference in the intensity of heat from that maintained by the associate referee and his collaborators. This seems apparent from information sup- 370 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 Taste 4. Study of the hydrolysis of refractory compounds. HYDROXY-| PYRIDIN , si) eT ee een ie es ANALYST Ree este SULPHATE ~ TIME ; Mercuric | Copper Nitrogen | Nitrogen oxid | sulphate found ound cc. grams grams gram gram hours per cent | per cent J. J. Vollertsen..| 25 10 or 0.2 a8 2 (fi. 6.7 25 10 ae 0.2 ae 23 6.6 5.8 25 10 ive 0.7 ae 23 7.9 9.3 35 10 eon 0.7 388 23 7.9 5 20 10 ae 0.7 = 13 te 9.3 25 10 Se 0.7 ses 13 Be a4 25 10 ieee sete 0.5 23 i x 25 10 a aren 10 | 23 58 | 58 20 ae 8.2 0.2 Bs 23 6.3 4.8 20 8.2 0.7 23 7.8 9.6 25} 8.2 at 23 8.0 8.0 25 10.0 0.7 23 7.8 8.7 20 8.2 0.7 2 Uh 6.9 20 8.2 0.7 13 2 6.7 20 8.2 0.65 2 6.5 Ts 20 8.2 0.65 13 6.4 7.3 Paul Rudnick...) 20 10 Bae 0.19 er 2 5.9 6.5 25 10 Poe 0.19 on 23 4.4 6.2 25 10 a 0.65 2 Na2S,0¢. DETERMINATION. Take such a quantity of the brine or water as will contain not more than 0.1 gram of iodin or more than 10.0 grams of total salts. Adjust the volume to 100-150 cc., add a sufficient quantity of the solution of sodium hydroxid and sodium carbonate, reagent (a), to precipitate the calcium and magnesium. Boil, filter off the precipitate of calcium and magnesium, and wash with hot water; introduce the filtrate into an Erlenmeyer flask, adjust the volume to about 100 cc., neutralize with dilute sulphuric acid, reagent (b), and add 1 ce. of the solution of sodium hydroxid, reagent (C). Heat to boiling, add an excess of potassium permanganate, reagent (d), about 0.5 cc. excess, continue heat- ing until the precipitate begins to coagulate and then allow to cool. Add sufficient alcohol, reagent (€), or hydrogen peroxid to bleach the permanganate color and set the beaker on a steam bath. When the precipitate has settled, filter and wash the precipitate with hot water. After cooling, add 1-2 grams of potassium iodid, acidify with hydrochloric acid and titrate with N/20 thiosulphate. One-sixth of the iodin titrated represents the amount originally present (1 cc. of N/20 thiosulphate solution equals 1.058 mg. of iodin). 1 Presented by W. W. Skinner. 2J. Ind. Eng. Chem., 1919, 11: 563. 3 Ibid., 954. 4 Assoc. Official Agr. Chemists, Methods, 1916, 47. 1921) SALE: REPORT ON WATER 381 The method for bromin in the presence of chlorin, but not iodin follows: APPARATUS. Two high form Dreschel gas washing bottles. An ordinary wash bottle. Join the three wash bottles as in Fig. 1. REAGENTS. (a) Sulphite reagent——Solution containing 4 grams of sodium sulphite and 0.8 gram of sodium carbonate per 100 ce. (b) Chromium triozid crystals. (C) 3% solution of hydrogen perozid. (G@) Potassium iodid crystals. (e) N/20 thiosulphate. A. B. Cc. A. REACTION CYLINDER. BEC.ABSORPTION CYLINDERS. 2 CrO; + 6 HBr = Cr.0; + 3 H;O + 3 Bro. E. RUBBER CONNECTIONS. 2 H.CrO, + 3 H,02 = Cr.0; + 2 02 + 5H. FIG. 1. GAS ABSORPTION APPARATUS. Na2SO; + 2 Br + H,0 = 2 HBr + NaSO,. REACTIONS. DETERMINATION. Evaporate the sample of water or brine, which should not be too acid, to dryness or nearly so. Charge the reaction cylinder A, Fig. 1, by introducing glass beads to a depth of about 1 inch, followed by 15 grams of solid chromium trioxid, and finally enough glass beads to fill the cylinder half full. Add 20 cc. of the solution of sodium sulphite and sodium carbonate, reagent (@), to the first absorption cylinder and 5 cc. to the second. Dilute each to about 200 cc. Connect the three cylinders and draw a current of air through slowly. Wash the sample into the reaction cylinder with water sufficient to make about 25 cc. of solution. Aspirate until the contents of the reaction cylinder are in solution and thoroughly mixed, then discontinue, close the inlet tube with a small piece of rubber tubing and clamp, and reduce the pressure in the apparatus slightly by sucking out some air in order to guard against any possible escape of bromin at the ground glass stopper. Allow to stand overnight, then aspirate with a rather strong current of air (about 3 to 3 liter per minute) for 3 hours, adding four 2 cc. portions of 3% hydrogen peroxid at 30-minute intervals. Stop the aspiration and evaporate the contents of the two absorption cylinders nearly to dryness. Clean out the reaction cylinder and freshly charge with glass beads and 15 grams of chromium trioxid. Into the first absorption cylinder put 10 grams of potassium iodid dissolved in 200 cc. of water and into the second 3 or 4 grams in a like amount of water. Connect the apparatus, draw through a slow current of air and transfer the contents of the evaporating dish to the reaction cylinder by means of the small funnel, using 25 cc. of water. Aspirate until all of the bromin is evolved (about 1 hour) and titrate the potas- sium iodid solution with thiosulphate (1 cc. of N/20 thiosulphate = 3.996 mg. of bromin). It will be noted that the method for bromin is to be used only in the absence of iodin. The authors state that iodin may be removed from the sample in which bromin is to be determined subsequently, as follows: 382 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 Introduce the neutral or slightly acid sample, which should contain not more than 0.1 gram of bromin or 10 grams of total salts into a distillation flask and adjust to a volume of approximately 75 cc., add 1.5-2.0 grams of ferric sulphate and distil the liberated iodin with steam into 100 cc. of a potassium iodid solution (10 grams of potassium iodid per 100 ce.). The potassium iodid solution may be titrated with sodium thiosulphate solution and the result used to check the figure obtained by the perman- ganate method. Taste 1. Composition of samples sent to collaborators. (Expressed as milligrams per 10 ce.) SOLUTIONS | CHLORIN BROMIN IODIN SULPHATE Ate Spear CALCIUM gees SODIUM Todin....| 603.0 | 340.6 34.13 LS 3.8 0.3 1.4 177.1 | 391.0 Bromin. .| 603.0 50.25 Peake 20 6.4 0.5 2.4 24.6 | 391.0 TABLE 2. Collaborators’ resulis on synthetic sample of brine. IODIN FOUND IN IODIN SOLUTION | BROMIN FOUND IN BROMIN SOLUTION ANALYST oO Meg. per 10 cc.| Mg. per 2 cc. || Mg. per 10 cc.| Mg. per 2 cc. J. H. Mitchell, Clemson Agri- 32.7 6.8 45.00 cultural College, Clemson 33.0 6.8 } 46.8 College, 8. C. 33.0 6.9 | ="138i4* 33.5 6.9 | aries 7.0 } W. G. Koupal, State Water 34.6 6.9 | 49.0 9.6 Survey Division, Urbana, Ill. 34.5 7.0 | 49:2 9.6 34.5 6.9 48.9 9.6 D. K. French, Dearborn Chem- 42.4* 8.4* 47.8 ical Co., Chicago, Il. 42.6* 8.4* 46.7 42.8* 8.6* 44.7 | 47.8* 2 | ore W. F. Baughman, Bureau of aoe aes 49.7 Chemistry, Washington, 4 49.7 D..Ce a W. E. Shaefer, Bureau of Chem- 34.5 7.0 49.7 9.9 istry, Washington, D.C. 34.7 7.0 48.7 9.7 34.6 7.0 | 49.3 10.2 L. H. Enslow, Filter Plant, 33.6 6.8 40.6* Gatun, Canal Zone, Panama. 33.8 6.8 42.0* 33.6 6.8 39.8* Da a 40.6* J. W. Sale 34.2 6.9 48.7 9.6 34.1 6.8 48.9 9.4 Lom ; 49.0 9.0 AVELApere eo oe ore toe oe 33.9 6.9 48.2 9.6 Theory) -feccchvaee asketesh ssc 34.13 6.83 50.25 10.05 * Omitted from average. Wiens... 1921] SALE: REPORT ON WATER 383 DISCUSSION OF IODIN METHOD. Results obtained by using hydrogen peroxid in place of alcohol in the method for iodin, as suggested by Enslow, are contained in Table 3. The results obtained are satisfactory. It is suggested that the use of hydrogen peroxid be optional in the method for iodin. TABLE 3. Results obtained by the use of hydrogen peroxid in place of alcohol to destroy excess per- manganate in the method for todin. IODIN FOUND BY ENSLOW IODIN FOUND BY SHAEFER Mg. in 10 ce. Meg. in 2 ce. Msg. in 10 ce. Mg. in 2 ce. 34.6 6.9 34.1 6.9 34.6 6.9 34.0 lost 34.6 6.9 34.0 7.0 Theory. .....34.13 6.83 | 34.13 6.83 An average of 33.9 mg. of iodin was obtained by the collaborators, the theory being 34.13 mg. The difference is 0.23 mg. or 0.7 per cent. On the smaller sample of iodin solution taken for analysis an average of 6.9 mg. of iodin was obtained, the theory being 6.83 mg. The difference is 0.07 mg. or 1.0 per cent. These averages are based on fifteen determina- tions in the first instance and sixteen in the second. The results obtained by one of the analysts have been omitted from the average as they were excessively high, due, perhaps, to the incomplete removal of the excess permanganate. After carefully considering the results submitted and the comments of the analysts, it is the opinion of the referee that the method for iodin is worthy of adoption as a tentative method by the association. DISCUSSION OF BROMIN METHOD. There appears to be no objection to the modification of the method for bromin suggested by Koupal and Shaefer, viz, that the chromic acid be added to the reaction chamber in solid form and that the sample after concentration be washed in, using as little wash water as possible. The last figures reported by the referee were obtained by using this modification of the method and they are satisfactory. An average of 48.2 mg. of bromin was obtained by the collaborators, the theory being 50.25 mg. The difference is 2.05 mg. or 4.1 per cent. On the smaller sample of bromin solution taken for analysis, an average of 9.6 mg. of bromin was obtained, the theory being 10.05 mg. The differ- ence is 0.45 mg. or 4.4 per cent. These averages are based on sixteen 384 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 determinations in the first instance and nine in the second. Five deter- minations have been omitted from the average on the large sample, four of them because the analyst was so situated that adequate laboratory equipment for conducting the test was not available. The method for bromin consistently gives slightly low results. The very best results obtained were 0.5 mg. low, and other results which may be regarded as fairly satisfactory were 1.0 to 1.5 mg. low. Under these circumstances, it may be well to state that the standard potassium bromid solution used in making up the synthetic sample was standard- ized by two analysts, both by weighing the potassium bromid as such and by precipitating the bromin as silver bromid, so that the theoretical figure for bromin content is undoubtedly correct. In considering these results it must be borne in mind that the deter- mination of bromin in mineral water and brines is one of the most tedious and unsatisfactory of any of the methods. The method proposed, while seemingly full of detail, requires, as a matter of fact, comparatively little attention after the analysis is started. It is freely conceded that it is not a method for an inexperienced worker, but there are no methods for bromin in the literature that are both accurate and rapid. It is believed that the method here proposed gives more dependable results than the colorimetric method of the association’. Under the circumstances set forth above, it is suggested that the method for bromin be adopted by the association as a tentative method. It is thought that the colorimet- ric methods for iodin and bromin should be retained by the association as tentative methods, as they will continue to give value from a qualita- tive standpoint. DETERMINATION OF THE AMMONIAS IN WATER CONTAINING SULPHID. Additional analytical work on the determination of free and albumin- oid ammonia in water containing sulphid, particularly as to the effect of the reagent used on the quantity of albuminoid ammonia obtained has been done during the past year and some of the results of numerous tests are contained in Tables 4 and 5. The laboratory work was carried out by W. E. Shaefer under the direction of the referee. Two methods of preventing sulphid from interfering with the deter- mination of free ammonia had been shown previously to be satisfactory. In one of these methods, which for reference will be called “‘the acid method”, the sample is acidified with a measured amount of sulphuric acid, the sulphid boiled off, the sample made alkaline with sodium car- bonate and ammonias determined by distillation and nesslerization of the distillate in the usual manner. In the other method, which for refer- 1 Assoc. Official Agr. Chemists, Methods, 1916, 47. 1921] SALE: REPORT ON WATER 385 ence will be called “the cadmium chlorid method”, the sample contain- ing sulphid is made alkaline with sodium carbonate, the sulphid precipi- tated with cadmium chlorid and, without filtering, the ammonias are determined in the usual way. TABLE 4. Free and albuminoid ammonia in water containing sulphid* (sulphid removed by boiling in acid solution.) (Analyst, W. E. Shaefer.) | & Es NITROGEN fe NUTR OGEN Ea 5 2 a z6 LSS 5 : aie 5 3 4 5 Sa o< AMMONIA : zg neva z3 = Zz OZ, a6 g Rie 8 aie = ae = Py Z ne Zz 12 Ze og 5 a 2 | azn 8 3 Zn ga | ge | RE | 28 a | Se s | ae BS ae ae = | Present) Found & % 5 & | Present} Found ke asa Sea ee lar |e Bly eae roe || tos mg ce. ce. mg. mg. mg. mg. 1 0.5/ 30 5 | 0.060 | 0.050 | —0.010 | 0.003 | 0.014 | 0.009 | —0.005 | 0.001 2, 0.5} 30 5 | 0.060 | 0.058 | —0.002 | 0.003 | 0.014 | 0.019 |+0.005 | 0.002 3 0.5| 30 5 | 0.160} 0.160} 0.000 | 0.012 | 0.014 | 0.017 |+0.003 | 0.001 4 0.5/ 30 5 | 0.160 | 0.164 |+0.004 | 0.012 | 0.014 | 0.014 0.000 | 0.001 5 5.0/ 30 5 | 0.085 | 0.094 |+-0.009 | 0.006 | 0.162 | 0.175 |+0.013 | 0.010 6 5.0} 30 5 | 0.085 | 0.104 |+-0.019 | 0.007 | 0.162 | 0.174 |+0.012 | 0.010 if 5.0} 30 5 | 0.114 | 0.142 |+-0.028 | 0.009 | 0.114 | 0.125 |+-0.011 | 0.008 8 5.0} 30 5 | 0.166 | 0.171 |+-0.005 | 0.012 | 0.076 | 0.098 |-+-0.022 | 0.006 9 5.0} 30 5 | 0.166 | 0.182 |+0.016 | 0.012 | 0.076 | 0.102 |+0.026 | 0.006 10 0.5) 30 5 | 0.517 | 0.544 |+0.027 | 0.024 | 0.051 | 0.059 |+0.008 | 0.004 11 5.0} 30 5 | 0.517 | 0.560 |+-0.043 | 0.032 | 0.051 | 0.061 |+0.010 | 0.003 12 5.0} 30 5 | 0.517 | 0.624 |+-0.107 | 0.032 | 0.051 | 0.075 |+ 0.024 | 0.006 13 5.0} 30 5 | 0.558 | 0.552 | —0.006 | 0.024 | 0.103 | 0.124 |+0.021 | 0.008 14 | 125.0} 30 5 | 0.517 | 0.576 |+0.059 | 0.032 | 0.051 | 0.071 |+0.020 | 0.006 15 | 125.0} 30 5 | 0.517 | 0.504 | —0.013 | 0.024 | 0.051 | 0.049 | —0.002 | 0.004 16 | 125.0} 30 5 | 0.558 | 0.576 |+0.018 | 0.032 | 0.103 | 0.121 |+0.018 | 0.008 4.757 | 5.061) .... | 0.276) 1.107/1.293) .... | 0.084 * PROCEDURE: Measured amounts of sulphuric acid were added to samples containing varying, but known quantities of sulphid and free and albuminoid ammonias. The sample was boiled until free from sulphid (7. e., about 20 minutes), made alkaline with sodium carbonate and the ammonias determined in the usual manner. The samples were prepared from boiled Washington City tap water, a standard solution of ammonium chlorid, a solution of hydrogen sulphid, and an infusion of leaves. By reference to Table 4, it will be noted that a total of 4.757 grams of nitrogen in the form of free ammonia was contained in sixteen samples, whereas 5.061 grams of nitrogen were found, a plus error of 6.4 per cent. The possible error in the reading of the Nessler tubes in all sixteen tests, however, was 0.276 gram of nitrogen as free ammonia, or 5.8 per cent, which, subtracted from the total plus error, leaves 0.6 per cent error on the free ammonia, due to the modification of the method. These data indicate that “the acid method” of preventing the sulphid from interfering is preferable to ‘the cadmium chlorid method’. The 386 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 TABLE 5. Free and albuminoid ammonia in water containing sulphid* (sulphid removed by precipi- tation with cadmium chlorid). (Analyst, W. E. Shaefer.) a 8 < NITROGEN < I a 5 NITROGEN I AS ic! G] z 5 z AS FREE -§o ALBUMINOID 5 = e > BE 3 AMMONIA bs = 2 AMMONIA - E 2 z o8 <8 3) a 5 Se | §& | 28_| 28 é az z ag ze | oa | E.es| 3 z RAG z BEg gS Atel ||aS El Present) Found = & | Present) Found BI ass #Z == nee Be Fe oak =| See g és S a a By a a ce. ce. mg. mg. mg. mg. 1 0.5 5 5 | 0.023 | 0.041 |+-0.018 | 0.002 | 0.023 | 0.008 | —0.015 | 0.000 2 0.5 5 5 | 0.023 | 0.036 |+-0.013 | 0.002 | 0.023 | 0.012 |—0.011 | 0.001 3 0.5 5 5 | 0.173 | 0.160 | —0.013 | 0.010 | 0.023 | 0.021 | —0.002 | 0.002 4 0.5 5 5 | 0.173 | 0.175 |+0.002 | 0.010 | 0.023 | 0.009 | —0.014 | 0.001 5 0.5 5 5 | 0.523 | 0.530 | +-0.007 | 0.030 | 0.023 | 0.008 | —0.015 | 0.000 6 0.5 5 5 | 0.523 | 0.500 | —0.023 | 0.030 | 0.023 | 0.009 | —0.014 | 0.001 z 5.0 5 5 | 0.073 | 0.059 | —0.014 | 0.004 | 0.023 | 0.009 | —0.014 | 0.001 8 5.0 5 5 | 0.073 | 0.058 | —0.015 | 0.003 | 0.023 | 0.009 | —0.014 | 0.001 9 5.0 5 5 | 0.173 | 0.112 | —0.061 | 0.008 | 0.023 | 0.016 | —0.007 | 0.001 10 5.0 5 5 | 0.173 | 0.096 | —0.077 | 0.008 | 0.023 | 0.103 |+-0.080 | 0.006 11 5.0 5 5 | 0.523 | 0.290 | —0.233 | 0.020 | 0.023 | 0.164 |+0.141 | 0.009 12 5.0 5 5 | 0.523 | 0.350 | —0.173 | 0.020 | 0.023 | 0.119 |+-0.096 | 0.006 13 | 125.0} 25 5 | 0.073 | 0.023 |—0.050 | 0.003 | 0.023 | 0.060 |+0.037 | 0.004 14 | 125.0] 25 5 | 0.073 | 0.021 | —0.052 | 0.001 | 0.023 | 0.061 |+-0.038 | 0.004 15 | 125.0} 25 5 | 0.173 | 0.092 |—0.081 | 0.008 | 0.023 | 0.089 |+-0.066 | 0.005 16 | 125.0} 25 5 | 0.173 | 0.076 | —0.097 | 0.004 | 0.023 | 0.105 |+-0.082 | 0.005 3.468 | 2.619] .... | 0.163] 0.368] 0.802] .... | 0.047 * PROCEDURE: Measured amounts of sodium carbonate and of cadmium chlorid were added _ to samples containing varying, but known quantities of sulphid and free and albuminoid ammonia. The ammonias were then determined in the usual manner. The samples were prepared from boiled Washington City tap water, a standard solution of ammonium chlorid and a solution of hydrogen sulphid. boiling off of the sulphid in acid solution has been practiced in the laboratory of the referee for several years and has been found satisfac- tory. It is believed that this modification can now be recommended as official. It has occurred to the referee that the methods of water analysis should be broadened to include the examination of products closely allied to water, such as brine and salt. In some instances the methods for water could be used without modification. In others, however, considerable modification would be necessary. It is believed that the interest of the future referees and collaborators in the work would be increased, and a real need for proper methods for the analyses of these products would be filled by the extension of the methods. In order that the association may take some action, this suggestion will be put in the form of a recom- mendation. 1921] SALE: REPORT ON WATER 387 RECOMMENDATIONS. It is recommended— (1) That the method for the determination of barium!', be adopted as official. (Second and final presentation of the method for action.) (2) That the method for the determination of manganese? be adopted as an additional official method. (Second and final presentation of the method for action.) (3) That the method for the determination of iodin in the presence of chlorin and bromin, page 380, be adopted as a tentative method. (First presentation of the method for action.) The method has not been published in the Proceedings as provided by By-law No. 7. (4) That the method for the determination of bromin in the presence of chlorin but not iodin, page 381, be adopted as a tentative method. (First presentation of the method for action.) The method has not been published in the Proceedings as provided by By-law No. 7. (5) That the method given below for free and albuminoid ammonia in samples containing sulphid be adopted as official. (First presentation of the method for action.) The method has not been published in the Pro- ceedings as provided by By-law No. 7. FREE AND ALBUMINOID AMMONIA. (In samples containing sulphid.) REAGENTS. (a) N/2 solution of sulphuric acid. (b) 5 N solution of sodium carbonate. (C) Ammonia-free water. (d) Standard ammonium chlorid solution.—One cc. is equivalent to 0.01 mg. of nitro- gen in the form of ammonia (NHs). (e€) Nessler reagent.—Dissolve 50 grams of potassium iodid in a minimum quantity of cold water. Add a saturated solution of mercuric chlorid until a slight permanent precipitate is formed. Add 400 cc. of a solution containing 200 grams of potassium hydroxid (or an equivalent quantity of sodium hydroxid), dilute to 1 liter, allow to settle, and decant. (f) Alkaline potassium permanganate solution—Dissolve 200 grams of potassium hydroxid and 8 grams of potassium permanganate in water and dilute to 1 liter. 1J. Assoc. Official Agr. Chemists, 1920, 4: 86. 2 Tbid., 85. 388 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 DETERMINATION. Place 500 cc. of the sample in a beaker or casserole, add 30 cc. excess of N/2 sulphuric acid solution. Boil the solution carefully until free of sulphid (about 20 minutes). Add about 300 cc. of distilled water and 8 cc. of 5 N sodium carbonate solution to a distilla- tion flask connected as described in the official method!, and distil until free from ammonia. Cool and add the cooled sample which has been freed from sulphid. Proceed with the distillation, addition of alkaline permanganate solution, etc., as described in the official method. (6) That the methods on water be extended to cover the examination of allied products, such as brine and salt. (7) That continued study be given to the determination of iodin and bromin and the heavy metals and to the use of equivalents in studying the character of waters. REPORT ON SOILS. By C. B. Lipman? (University of California, Berkeley, Calif.), Referee on Soils. The report covers work undertaken two years ago on “The Total Phos- phorus Determination”. Of those who had promised to collaborate, only two sent in reports; namely, H. C. McLean (Agricultural Experiment Station, New Brunswick, N. J.) and L. A. Steinkoenig (Bureau of Soils, Washington, D. C.). The two former official methods* for total phos- phorus determination, namely, the magnesium nitrate method and the sodium peroxid method which the association adopted two years ago as tentative’, were studied. Two California soils, the Davis soil and the Oakley soil, were employed. The results obtained by the two collabora- tors are given in the following table: Determination of total phosphorus—results as phosphorus of water-free soil. DAVIS SOIL OAKLEY SOIL MCLEAN STEINKOENIG MCLEAN STEINKOENIG Mag- | Sodi Mag- | Sodi Mas- | Sodi Magnesi Sodi nesium | Deroxid | Resim | jeroxid || eS | peroxid | nitrate, | peroxid Saethod method eoehiad method Eacthod method method method per cent per cent per cent per cent per cent per cent per cent per cent 0.066 0.061 0.056 0.066 0.045 0.045 0.043 0.036 0.066 0.063 0.055 0.067 0.043 0.046 0.043 0.035 0.065 0.061 eters sess 0.045 0.045 aes Abiec 0.064 0.061 coun aos 0.045 0.044 1 Assoc. Official Agr. Chemists, Methods, 1916, 36. 2 Presented by W. H. MacIntire. 3 Assoc. Official Agr. Chemists, Methods, 1916, 25-6. 4 J. Assoc. Official Agr. Chemists, 1920, 4: 295. 1921] MACINTIRE: LIME ABSORPTION COEFFICIENT OF SOILS 389 In Steinkoenig’s case, two additional methods to those for which directions were issued were tried on the same samples. On studying these results, your referee finds that determinations made in quadrupli- cate by McLean in every case with each method and with each soil agreed well among themselves. The duplicate results obtained by Stein- koenig also agree well among themselves. The agreement between the results of the two collaborators is not so good as could be desired. Mc Lean’s results show that there is little choice between the two methods, though there is a possibility that the magnesium nitrate method is a little more thorough. This is just a possibility, however, and is offset by a certain difficulty in dehydration which was experienced by McLean with the method. With the Oakley soil even this slight difference be- tween the two methods seems to have disappeared. In the case of McLean’s results, the magnesium nitrate method is superior for the Oakley soil and the sodium peroxid method superior for the Davis soil. On the whole, your referee can not see sufficient difference between the figures submitted to justify drawing any other conclusion than that both methods so far adopted remain as they are for at least another year. RECOMMENDATION. It is recommended that the study of the determination of total phos- phorus in soil be continued with a larger number of soils and that an attempt be made to secure more collaborators. There was no associate referee on the nitrogenous compounds of soils and no report on this subject was presented. REPORT ON THE LIME ABSORPTION COEFFICIENT OF SOILS. By W. H. MacIntire (Agricultural Experiment Station, Knoxville, Tenn.), Associate Referee. During the past two years abnormal conditions have seriously handi- capped any extensive work along collaborative lines. The unusual demand placed upon station facilities has necessitated the suspension of all work not of primary importance. For this reason, those who offered collaborative assistance have been unable to fulfill the proffer made. However, following the more exhaustive previous report! made upon the results secured through selective collaboration upon representative procedures, and the adoption of the recommendation that the Jones 1 J. Assoc. Official Agr. Chemists, 1920, 4: 108. 390 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 calcium acetate method be further studied, the writer has given, with some assistance, special attention to the fundamentals of the method and the technic of the procedure. Exchange of opinions as to the merits of the method has brought out the fact that the Jones method is well adapted to its intended use. Without in any sense being derogatory to other procedures, which may be well adapted to certain conditions, it seems to be the consensus of opinion that the Jones calcium acetate method fills the need of an absorption method to replace the abandoned sodium nitrate procedure. Results from the Vermont and Virginia Agricultural Experiment Sta- tions indicate a close parallel between results secured by the Jones pro- cedure and those obtained by the method of Veitch. While it is true that the principles underlying the Veitch procedure are fundamentally correct from a physical chemical viewpoint, the method is not so well adapted to rapid laboratory manipulation as is the Jones procedure. Results secured during three years, and in particular the slight varia- tions reported in the factor, found applicable to different soils, together with the factor utilized in the Jones procedure, tend to justify the con- clusion that the method, after certain slight editorial changes and modi- fications in technic are introduced, may well be adopted tentatively as a laboratory procedure for the purpose of determining the lime absorp- tion coefficient of soils. These slight modifications have been presented to the originator of the procedure, C. H. Jones, Agricultural Experiment Station, Burlington, Vt., and have received his sanction. JONES METHOD FOR DETERMINING LIME ABSORPTION COEFFICIENT. Take 5.6 grams of soil, add 0.5 gram of calcium acetate (tested reagent), place in a 3-inch mortar and mix with a pestle. Add sufficient water (room temperature) to make a fairly stiff paste. Pestle for 20 seconds, add 30 cc. of water and continue the mixing for 30 seconds. Wash into a 200 cc. flask and keep the bulk down to about 160 cc. Let stand with occasional shaking for 15 minutes. Make up to a bulk of 200 ce., mix and filter through a dry filter. Discard the first 10-15 cc. which may be cloudy. For rapidity and efficiency the Biichner funnel is recommended. Titrate 100 cc. of the clear filtrate, using phenolphthalein as an indicator, with N/10 sodium hydroxid. This reading multiplied by 2 gives the number of cc. of N/10 alkali required to neutralize the acetic acid in 200 cc. of the solution. This figure times the factor 1.8 times 1000 indicates the pounds of lime (CaO) required per 2,000,000 pounds of soil. RECOMMENDATION. If further study of the tentative method be thought advisable, it is recommended that such a study be made upon the factor of soil type in its influence upon variation in the factor to be applied. 1921] MITCHELL: INORGANIC PLANT CONSTITUENTS 391 REPORT ON INORGANIG PLANT CONSTITUENTS. By J. H. Mrrcnetz! (Clemson Agricultural College, Clemson College, S. C.), Referee. I wish to review, briefly, the work that has been done on this subject during the past five years. In 1915 A. J. Patten® showed that the present molybdate method for the determination of iron, aluminium, phosphorus, calcium and magnesium was not accurate when used on material con- taining a large amount of phosphorus and low percentage of calcium and magnesium. This condition exists in such material as the ash from cereals, legumes and many seeds. No collaborative work was done in 1915, but the referee did some work on a method for calcium and mag- nesium. The following recommendation was made: “That suitable methods be devised for the determination of iron, aluminium, calcium and magnesium in the ash from seeds”. In 1916 Patten presented a method for determining calcium and magnesium in the presence of phosphoric acid, iron and aluminium; also a method for determining manganese colorimetrically. No collaborative work was done, but it was recommended that the methods as outlined for calcium, magnesium and manganese be further studied on solutions approximating the composition of the ash of cereals, seeds, etc. In 1917 and 1918 no recommendations were made, so the present referee decided to continue the study of the methods for the determination of calcium, magnesium and manganese in the presence of a large amount of phosphorus, as recommended and approved in 1916. A synthetic ash solution was made of approximately the compostion of the ash of certain seeds, cereals and legumes. It contained iron, aluminium, phosphorus, calcium, magnesium and manganese in the following proportions: per cent Herricroxtels (ers oe saree ee es eer ee 1.43 Aluminium oxid (Al,05) SO 6 OSICACCIOR IOLA oo Oe 1.93 Phosphorus pentoxid (P20s)................-. 38.73 Calermioxidi(CaO)t ss eek aos He teed 2h 5.46 Magnesium oxid (MgO).............. dese Dai 4.30 Manganomanganic oxid (Mn;Q,).............. 0.30 A sample of this solution was sent to eight chemists. The following table shows the results obtained: 1 Presented by W. L. Latshaw. 2 J. Assoc. Official Agr. Chemists, 1917, 3: 153. 2 Ibid., 1920, 3: 329. 392 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 Results on synthetic solution. CHEMIST CALCIUM OXID | MAGNESIUM OXID Taatencen per cent per cent per cent Benj. Freeman, Clemson Agricul- 5.32 4.82 tural College, Clemson College, S: GC: A. P. Kerr, Department of Agricul- 5.60 4.34 ture and Immigration, Baton Rouge, La. J. F. King, State Department of ae 4.20 Agriculture, Atlanta, Ga. W. L. Latshaw, Agricultural Ex- 5.45 4.47 periment Station, Manhattan, 5.54 4.53 Kans. 5.48 4.50 J. S. McHargue, Agricultural Ex- 5.27 4.66 ee periment Station, Lexington, Ky. 5.27 4.72 0.341 5.33 ote sedis J. H. Mitchell 5.44 4.24 0.332 5.44 4.25 0.326 5.50 4.29 wa Percy O'Meara, Agricultural Ex- 5.57 4.80 0.322 periment Station, E. Lansing, 5.54 4.76 j 0.325 Mich. 5.60 4.76 0.334 IAVETARE Ne Ry oo KSEE IS BE 5.45 4.52 0.33 aheorny ee. ace ee eee 5.46 4.30 0.30 Differences 34s ea epee 0.01 0.22 0.03 These results vary somewhat, yet taken as a whole they are very good, especially those for calcium. The results on magnesium show a little wider variation and are, on the average, higher than the theory. Owing to a difficulty in obtaining potassium periodate, only a few results were obtained for manganese. These, however, were very good. The following is an outline of the methods sent to the different chemists: CALCIUM. Remove 25 cc. of the solution, representing 0.5 gram of ash, and dilute to 200 cc., add a few drops of alizarine or methyl orange and make slightly ammoniacal. Add very dilute hydrochloric acid (1 to 10) until the solution is just faintly acid, followed by 10 ce. of N/2 hydrochloric acid and 10 cc. of 2.5% oxalic acid. Boil the solution and add, with constant stirring, 15 cc. of a saturated solution of ammonium oxalate, and continue to heat until the precipitate becomes granular. Cool and add, with con- stant stirring, 8 cc. of 20% sodium acetate solution, and allow to stand 12 hours. Filter, and wash with hot water until free from chlorids. Dissolve the precipitate in hot, dilute sulphuric acid and titrate with N/10 potassium permanganate solution. In dissolving the precipitate it is best to first wash it off the paper into a beaker, and dissolve the portion remaining on the paper with hot dilute sulphuric acid (1 ec. N/10 KMn0O, = 0.0028 gram CaO). 1921] MITCHELL: INORGANIC PLANT CONSTITUENTS 393 MAGNESIUM. To the combined filtrate and washings from the calcium determination, add 25 cc. of strong nitric acid and evaporate to dryness. Take up with dilute hydrochloric acid and make to a volume of about 100 cc. Add 5 cc. of a 10% sodium citrate solution and 10 cc. of sodium hydrogen phosphate solution, or enough to precipitate all of the mag- nesium. Add dilute ammonium hydroxid, with constant stirring, until the solution is faintly alkaline; then add about 25 cc. of strong ammonium hydroxid and set aside in a cool place overnight. Filter and wash with 2.5% ammonium hydroxid solution. Dissolve the precipitate in dilute hydrochloric acid and reprecipitate as before. Allow to stand several hours, filter and wash free of chlorids with 2.5% ammonium hydroxid solution, ignite and weigh as magnesium pyrophosphate. MANGANESE, To 25 cc. of the solution, representing 0.5 gram of ash, add about 15 cc. of con- centrated sulphuric acid and evaporate to expel hydrochloric acid. When the solution has reached a small volume, add 5-10 cc. of nitric acid and continue the evaporation. It is neither necessary nor desirable to evaporate until dense fumes appear, since the ferric sulphate then dissolves with difficulty. Nitric acid may be present, but not hydrochloric. Add water, a little at a time, heat until the iron salts have dissolved, and dilute to about 150 cc. Add about 0.3 gram of potassium periodate, heat just to boiling for a few minutes and allow to cool. The standard is prepared in the following manner: To a volume of water equal to the sample, add 15 cc. of sulphuric acid and sufficient pure ferric nitrate, free from manganese, so that this solution will contain about the same amount of iron (about 1 per cent) as the sample. Add standard per- manganate solution, noting the amount, until the color is slightly darker than the sample, and then the same amount of periodate and boil as before. When cool, transfer the sample and standard to 250 ce. flasks and make to the mark. If the color is weak it may be necessary to make to smaller volume. Compare the colors in any standard colorimeter. Report as Mn;Ox. These methods seem to be quite promising, and with further study probably can be perfected so as to give excellent results. The associate referee, W. L. Latshaw, has taken considerable interest in this work. In addition to making the determinations of calcium and magnesium, as outlined in these methods, he has made a comparative study of the present official method and these new methods on samples of cottonseed meal and alfalfa meal. He has also been working on a method for the determination of iron and aluminium in the filtrate from the magnesium. His results and comments are as follows: I am highly pleased with the results obtained by the methods as outlined. They haye a distinct advantage over the old procedure for the determination of calcium and magnesium in material high in phosphorus, as it seems impossible even with several reprecipitations of the phosphorus, iron and aluminium, to remove all of the calcium and magnesium. I tried this out very carefully, using the sample submitted, also the cottonseed meal and alfaifa meal. The results on calcium and magnesium from the collaborative sample and cottonseed meal sample were very low, as compared with the results obtained by the methods outlined for collaborative work, while the results obtained with alfalfa showed much better agreement with the two methods, although 394 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 somewhat lower with the official method. I attributed these low results to the larger amount of phosphorus in the cottonseed meal and in the sample submitted for analysis. The amount was so much less in the case of alfalfa that it did not make it difficult to wash the precipitate free of calcium and magnesium, thus allowing for the fairly good comparison in the case of the alfalfa. I have tried several procedures for the recovery of iron and aluminium after the removal of calcium and magnesium. While I have not obtained any definite results, the work performed has been sufficient to convince me that is is entirely feasible to find a good working method, and I think we should work towards this end, another year. I have done a little work on phosphorus. The fusion method I used for determining phosphorus was originally worked out for the determination of iodin in thyroid glands of animals and is applicable to halogens. I think that some work should be done during the coming year on phosphorus and chlorin, especially in the seeds of plants. The following table indicates the results obtained by these different methods. The material was ashed in a platinum dish by the aid of an electric muffle furnace, accord- ing to the official method for the preparation of the ash. Ten grams of the material were used in the case of the cottonseed meal, and 5 grams of alfalfa meal. Determination of calcium and magnesium in cottonseed and alfalfa meal. (Analyst, W. L. Latshaw.) PROPOSED METHOD OFFICIAL METHOD MATERIAL Calcium oxid Magnesium oxid Calcium oxid Magnesium oxid per cent per cent per cent per cent Cottonseed meal 0.29 0.94 0.064 0.324 0.30 0.93 0.105 0.360 0.23 0.91 0.105 sremne Alfalfa meal 2.20 0.37 1.96 0.335 2.24 0.37 1.86 0.310 2.05 0.40 sees 2a The phosphoric acid content of the cottonseed meal was approximately 2 per cent, while that of the alfalfa meal was in the neighborhood of 0.5 per cent. RECOMMENDATIONS. It is recommended— (1) That the methods as outlined in this report for calcium and magnesium be made tentative for the ash of such material as seeds, and that further work be done on them during the coming year. (2) That the colorimetric method for manganese be further studied, possibly with the use of several oxidizing agents. (3) That a method be devised for the determination of iron and aluminium in the filtrate from the magnesium. (4) That a study of the present method for phosphorus and chlorin be made on material corresponding to the ash of seeds. 1921] WINTER: REPORT ON INSECTICIDES 395 REPORT ON INSECTICIDES AND FUNGICIDES". By O. B. Winter (Agricultural Experiment Station, E. Lansing, Mich.), Referee. The insecticide work for 1918 and 1919, in accordance with the recom- mendations of the association, has been a further cooperative study along the following lines: 1. The determination of lead, zinc and copper in a product which may contain arsenic, antimony, lead, copper, zinc, calcium, magnesium, etc., e. g., Bordeaux-lead arsenate with Bordeaux-zinc arsenite. 2. The removal of the color in London purple before the determina- tion of the total arsenic. 3. The comparison of the official iodin, the Gyory bromate, and the Jamieson iodate methods for the determination of arsenic. The referee has also considered methods for the determination of the calcium, magnesium, zinc, and soluble arsenic in calcium and magnesium arsenates and zinc arsenite, the total arsenic in magnesium arsenate, and the arsenic trioxid in calcium and magnesium arsenates, since the association has no methods, either official or tentative, for making these determinations. Early in 1918, five collaborators, including the referee, manifested a willingness to cooperate in the work, and samples were sent to them with directions for carrying on the work. Only two reports were received during 1918. The same work was continued in 1919 and four additional reports were received. BORDEAUX-LEAD ARSENATE WITH BORDEAUX-ZINC ARSENITE. The sample of Bordeaux-lead arsenate with Bordeaux-zine arsenite was prepared by thoroughly mixing known quantities of lead arsenate, zine arsenite, and dry Bordeaux mixture. Each of these materials was prepared and analyzed according to the directions used in preparing similar materials for the insecticide work in 19172. By calculation, this sample should contain 17.38 per cent of lead oxid; 7.49 per cent of copper; and 11.31 per cent of zine oxid. The methods sent to the collaborators for the determination of lead, copper, and zinc were as follows: 1 Presented by A. J. Patten. 2 J. Assoc. Official Agr. Chemists, 1920, 4: 134. 396 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 GENERAL PROCEDURE FOR THE ANALYSIS OF A PRODUCT CONTAINING ARSENIC, ANTIMONY, LEAD, COPPER, ZINC, IRON, CALCIUM, MAGNESIUM, ETC. (Applicable to such preparations as Bordeaux-lead arsenate; Bordeaux-zine arsenite; Bordeaux-Paris green; Bordeaux-calcium arsenate, etc.) LEAD OXID (PbO)! COPPER (CuO). ZINC OXID (Zn0)*. The results obtained on this sample are found in Table 1. TABLE 1. Bordeauz-lead arsenate with Bordeauz-zine arsenite. ANALYST *E(PbO) ace ZnO) per cent per cent per cent 1. J. J. T. Graham, Bureau of 17.61 7.78 10.80 Chemistry, Washington, D. C. 17.35 7.74 10.88 17.53 7.78 11.12 17.31 a AVOLAge’. occ ere semen 17.45 7.77 10.93 2. C. B. Stone, Bureau of Chemis- 17.52 7.56 11.14 try, Washington, D. C. 17.58 7.60 11.24 17.51 7.64 11.00 17.43 (esy4 tans 17257 Shete IAV ERA ge ive onecoreys aersteeeia ais eee 17.52 7.58 11.13 3. Percy O’Meara, Agricultural LSE ae 11.23 Experiment Station, E. Lansing, 17.38 7.24 11.30 Mich. AV Crape hanson cee cscs 17.44 7.24 La ePe7/ 4. O. B. Winter, Agricultural Ex- 17.25 7.52 11.15 oe Station, E. Lansing, 17.41 7.50 11.30 ich. IAVETABC! woe cms eee 17.33 7.51 11.23 General average..........-... 17.44 7.53 11.14 Theoryeeoissce sc eceton ee 17.38 7.49 11.31 DISCUSSION. As stated in the 1917 Report on Insecticides’, the problem involved in making the determinations found in Table 1 is a question of the 1 J. Assoc. Official Agr. Chemists, 1920, 4: 136. 2 [bid., 137. 3 [bid., 134. 1921] WINTER: REPORT ON INSECTICIDES 397 separation of lead, copper and zinc in the presence of other compounds. Since in such a problem it is not easy to make a comparison with any standard method, especial care was taken to analyze the individual compounds before the composite sample was prepared. These results are given in the last line in the table. It must be borne in mind, how- ever, that these results would vary somewhat if it had been possible for each analyst to make the individual determinations. It is to be regretted that so few chemists have cooperated in this work, especially since the results do not agree so well as might be desired. The small amount of work done hardly justifies that any action be taken on the method but it should receive further cooperative study. LONDON PURPLE. The London purple used in this work was a commercial sample which had been received at the writer’s laboratory for analysis. TOTAL ARSENIC. REAGENTS. Standard solutions —As given under Paris green’. Zine oxid-sodium carbonate mizture-——Mix four parts of zinc oxid with one part of dry sodium carbonate. Blood charcoal. DETERMINATIONS. Official todin method.—Determine as directed under London purple. Zinc oxid-sodium carbonate method.—W eigh an amount of sample equal to the arsenic trioxid equivalent of 250 cc. of the standard iodin solution. Mix the sample thoroughly with several times its weight of the zinc oxid-sodium carbonate mixture in a shallow porcelain crucible and cover with a layer of the same mixture. Place the crucible, uncovered, in a muffle, heat, gently at first and finally for about 15 minutes at full heat. (The mass will not sinter.) Cool, transfer to a distillation flask and proceed according to the official distillation method for total arsenic in Paris green’. Adsorption method.—Proceed as directed under the official iodin method for total arsenic in Paris green, except that 3-4 grams of blood charcoal are added to the dis- tillation flask before beginning the distillation. The results obtained on this sample are found in Table 2. COMMENTS BY ANALYSTS. One analyst found it impossible to get a colorless solution in the official method. A colorless distillate was obtained by all the collabora- tors in the zine oxid-sodium carbonate and blood charcoal adsorption methods. Two analysts noted a tendency to foam in the blood charcoal 1 Assoc. Official Agr. Chemists, Methods, 1916, 63. 2 Ibid., 66. 3 Ibid., 64. 398 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 TABLE 2. Total arsenic expressed as arsenic triozid in London purple. ZINC OXID- SODIUM ADSORPTION ANALYST OFFICIAL METHOD GaanONcne SS METHOD se per cenl per cent per cent 1. J. Jen Graham 39.67 39.78 39.03 39.60 39.87 39.15 39.52 39.90 39.11 39.56 39.90 Pee ANOLARC cc cerierPree ce eieieciee 39.59 39.86 39.10 2. C. B. Stone 39.52 39.72 39.13 39.48 39.72 39.13 39.56 39.87 39.27 sisiave 39.88 39.27 AV EPA Be ionic nnasknasos ssa 39.52 39.80 39.20 3. Percy O'Meara 39.50 40.20 39.80 39.62 40.10 39.80 ade bene 40.30 40.20 IANELA BCs cc5 cvcr<, c/a) cvavere ava tetasererers 39.56 40.15 40.03 4. O.B. Winter 39.57 39.70 39.56 39.63 39.74 39.69 39.57 39.76 aids IAN CLARO ena o85. onstoisterernerci serie ai 39.59 39.73 39.63 General average.............. 39.56 39.89 39.49 adsorption method and a third analyst stated that the charcoal collected on the sides of the flask during the distillation and required an occasional shaking. Two analysts expressed a preference for the zinc oxid-sodium carbonate method, while a third preferred the blood charcoal adsorption method. DISCUSSION. A study of Table 2 shows that the results by the different analysts for total arsenic in London purple by the official method agree very closely indeed. With one exception the results by the zinc oxid-sodium car- bonate method also agree well, but run about 0.30 per cent higher than by the official method. The results by the adsorption method are very low by two analysts. They are high by one analyst, and agree fairly well with the official method by another analyst. Undoubtedly, these methods deserve further study. 1921] WINTER: REPORT ON INSECTICIDES 399 PARIS GREEN. The Paris green used in this work was a commercial sample received at the writer’s laboratory for analysis. TOTAL ARSENIC. REAGENTS. Starch indicator.—Prepare as directed under Paris green. Standard arsenic triorid solution.—Prepare as directed under Paris green'. Standard iodin solution'—Prepare as directed under Paris green. Standard potassium bromate solution.—Dissolve 1.687 grams of pure potassium bromate (dried at 140°C.) in water and dilute to 1 liter. One cc. of this solution is equivalent to 0.00300 gram of arsenic trioxid. Standard potassium iodale solution.—Dissolve 3.244 grams of potassium iodate (dried at 140°C.) in water and dilute to 1 liter. One cc. of this solution is equivalent to 0.00300 gram of arsenic trioxid. DETERMINATIONS. Official iodin method.—Determine as directed under Paris green?. Gyory bromate method.—Proceed as directed under the official iodin method, except that the distillate is made to 500 instead of 1000 cc*. (a) Transfer a 100 cc. aliquot to a 500 cc. Erlenmeyer flask, heat almost to boiling and titrate with the standard bromate solution, using methyl orange as indicator (the indicator should not be added until near the end of the reaction). (b) Same as (A) except titrate without heating. Jamieson iodate method.—Proceed as directed under the Gyory bromate method until the distillate is made to a volume of 500 cc. Transfer 100 cc. aliquots to 250-500 cc. glass stoppered bottles, add 6 cc. of chloroform and about 10 cc. of concentrated hydrochloric acid, and titrate with the standard iodate solution until the disappear- ance of the iodin from the chloroform, when the mixture is thoroughly shaken‘. Nore.—In both the bromate and iodate methods the number of cc. of standard solu- tion used, multiplied by 2, represents the per cent of total arsenic in the sample expressed as arsenic trioxid. ARSENIC TRIOXID. C. C. Hedges modified method —Determine as directed under Paris green®. Gyory bromate method.—Weigh an amount of the sample equal to the arsenic trioxid equivalent of 50 cc. of the standard bromate solution, transfer to a beaker, add about 50 ce. of water and 15 cc. of concentrated hydrochloric acid, heat almost to boiling, and titrate with the standard bromate solution as directed under total arsenic. Jamieson iodate method—Weigh an amount of sample equal to the arsenic trioxid equivalent of 50 cc. of the standard iodate solution, transfer to a 250-500 cc. glass stoppered bottle, add 20 cc. of water and 30 cc. of concentrated hydrochloric acid, and titrate with the standard iodate solution as directed under total arsenic. Notre.—In these two latter methods, the number of cc. of standard solution used,. multiplied by 2, represents the per cent of arsenious oxid in the sample. 1 Assoc. Official Agr. Chemists, Methods, 1916, 63. 2 [bid., 64. 3 Z. anal. Chem., 1893, 32: 415. 4 J. Ind. Eng. Chem., 1919, 10: 291. 5 Assoc. Official Agr. Chemists, Methods, 1916, 64. 400 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 Remarks on the directions for analysis: 1. The reaction of a bromate, and of an iodate on arsenic trioxid undoubtedly may be represented by the following two equations': 3 As.O; + 2 KBrO; + HCl = 3 As,O; + 2 KBr + HCl As,0; + KIO; + 2 HCl = As,O; + IC] + KCl + H,0. 2. Sodium bromate or sodium iodate may be used instead of the potassium salts. 3. Both the standard bromate and iodate solutions were found approximately accurate by the referee. However, it is not definitely known that these salts as found on the market are sufficiently pure for making up the standard solutions as directed. Therefore, it is desirable that each collaborator standardize his solution against arsenic trioxid, and report the results. The results obtained on this sample are shown in Tables 3 and 4. TABLE 3. Total arsenic expressed as arsenic triozid in Paris green. BROMATE METHOD ANALYST OFFICIAL —————————— IODATE METHOD METHOD (Hot) (Cold) per cent per cent per cent per cent 1. J. J.T. Graham 56.40 56.26 57.09 56.47 56.40 55.99 57.09 56.30 56.51 56.09 57.09 56.56 56.59 56.46 57.09 56.19 wet 56.91 Se As 56.81 INNOTARC. coir aie feiers auspcheue paisa 56.48 56.42 57.09 56.38 2. C. B. Stone 56.57 56.60 56.97 56.54 56.63 56.60 56.79 56.36 56.57 56.79 56.97 56.54 ers ae 56.97 56.53 Average: <5. cetsinos see tee oe 56.59 56.66 56.93 56.49 3. Percy O’Meara 56.40 57.00 57.00 56.53 56.60 57.00 57.10 56.63 56.80 Soir ae 56.63 56.80 a sais wate pees? AVGL8RC. ac occ carne eee 56.65 57.00 57.05 56.60 4. O.B. Winter 56.49 56.55 56.80 56.40 56.33 56.45 a5 56.50 IAVETARE cute ctenete a ne eer 56.41 56.50 56.80 56.45 General average............ 56.53 56.65 56.97 56.48 Prescott and O. C. Johnson. Qualitative Chemical Analysis. 6th ed., 1915, 349, 358; J. Ind mee ae 1918, 10: 291. 1921] WINTER: REPORT ON INSECTICIDES 401 TABLE 4. Arsenic trioxid in Paris green. BROMATE METHOD ANALYST OFFICIAL IODATE METHOD METHOD (Hot) (Cold) per cent per cent per cent per cent 1. J. J.T. Graham oe 55.42 Sater 55.58 Se 55.42 ate 55.58 55.52 oe 55.58 / Si GiR 1 A ee EGE: a 55.58 2. C. B. Stone Seine 55.49 ete 55.75 Sin 55.68 Mi: 55.55 55.49 Sa 55.55 AVEPARON < 5 . Juniper berries............... PESRES NNT oe aie fafa vests 515. oSiS.cjalecaes MENCOROUMN: « so) ss eres: Tyeopodlum.... .< 2 = = I tegiece a5 a | < c & = iol > D2 2 E : ela eC E | oze8 a < = =@ 2 = PS] = = o.- > < > = == =H) 5 & z Es ° halas & | | per cent per cent 16631 | Santal oil, U. S. P. 1.50* | —18.2f 89.7 193.7 85.1 1 : 2.28 16837 | Santal oil, 90% | 1.502¢ —17.1i | 93.7 201. §3.9 1: 2.39 Castor oil, 5% Balsam copaiba, 5% 16838 | Santal oil, 85% | 1.501* —17.9§ 83.1 181.4 74.0 | 1:2.45 Copaiba oil, 10% Olive oil, 5% | 19328 | Santal oil, 80% 1.4995* | —16.97 | 87.1 | 188.8 | 73.9 | 1:2.55 Copaiba oil, 10% | Castor oil, 5% Olive oil, 5% 19329 | Santal oil, 80% 1.498* —15.8* | 86.2 | 187.2] 69.6 | 1:2.69 Copaiba oil, 5% } Olive oil, 15% | 19327 | Santal oil, 80% | 1.4963* | —15.9§ | 90.6 | 195.3] 72.3 | 1:2.70 Copaiba oil, 5% Coconut oil, 15% 19326 | Sandalwood oil, grossly | 1.4795* —3.1* | 107.6 295.8 | 344 |1:6.56 adulterated (com- | } mercial sample) * At 25°C. § At 26°C. that it is possible to add appreciable amounts of foreign oils and still, when assayed by the United States Pharmacopeeia method, have present apparently over 90 per cent of alcohols calculated as santalol, as required by the United States Pharmacopeeia. When the alcohols are calculated from the true acetyl value, however, this figure is materially reduced. It would appear also that the ratio of the saponification number of the acetylated oil to the acetyl value, expressed as santalol, furnishes a significant figure, this ratio becoming progressively greater with the increase in the amount of foreign oils. The meeting adjourned at 5.30 p. m. for the day. SECOND DAY. TUESDAY—MORNING SESSION. No report on saccharine products was made by the referee. REPORT ON MAPLE PRODUCTS. By J. F. Snett (Macdonald College, Quebec, Canada), Associate Referee. Seven samples of sirup were distributed to collaborators in 1918 and work upon the same samples was continued in 1919. The samples were as follows: No. 1.—Pure, Quebec 1917, Grade I; Canadian lead number, 2.74. No. 2.—Pure, Quebec 1918, Grade II; Canadian lead number, 3.60. No. 3.—Adulterated, prepared from No. 5 and a “‘brown”’ cane sugar. No. 4.—Adulterated, prepared from No. 5 and granulated sugar. No. 5.—Pure, Quebec 1918, Grade III. No. 6.—Adulterated, prepared from a Quebec 1918, Grade I, maple sirup and a sugar cane product; Canadian lead number of the pure sirup, 3.97. No. 7.—Adulterated, prepared from the same maple sirup used in No. 6 and a “brown” cane sugar. In 1918 collaborators were instructed to study: (1) Preparation of the sample; (2) Winton lead method; (3) Canadian lead method; (4) con- ductivity value method. In 1919 they were asked to determine: (5) Ash values; (6) malic acid value. In both years they were asked to report refractometer moisture results on the samples as received and to state their judgment as to the purity of the samples, making use of supple- mentary methods if necessary. Basing his judgment upon the Canadian lead numbers, A. Valin (Laboratory of the Inland Revenue Department, Cttawa, Canada), in 1918, expressed the opinion that Samples 2, 5 and 7 were genuine, the other four probably adulterated. N. C. McFar- lane (Macdonald College, Quebec, Canada), in 1919, applying the volumetric lead method', adjudged Nos. 1, 2 and 5 genuine and No. 7 doubtful. The other collaborators did not venture an opinion. MOISTURE RESULTS. The results of the moisture determinations are given in Table 1. The wide variation in results is not to be emphasized, inasmuch as it may be due partly to actual differences in the portions of the individual 1 J. Ind. Eng. Chem., 1916, 8: 241; J. Assoc. Official Agr. Chemists, 1920, 4: 169. 428 1921] SNELL: REPORT ON MAPLE PRODUCTS 429 samples included in the various sets of seven. The samples, after they were subdivided and bottled, were sterilized by heating the filled bottles in a covered pan of boiling water. G. J. Van Zoeren (Macdonald College, Quebec, Canada), who prepared the samples, reports that in this process he found it necessary to remove the cork stoppers and cover the bottles with inverted beakers. Inasmuch as seis were sterilized together it is not impossible that different quantities of water distilled out of the various portions of the samples of identical number. The results are arranged in Table 1 according to a suggestion made by Hugh Main, London, England, to whom the results were sent for criticism. Main, not being advised of the possibility of actual differ- ences in the portions of the samples, suggests that probably the control of temperature is the chief source of error. His custom is to work in a room kept as near 20°C. as possible, pass water at 20°C. through the prism jacket of the Abbé refractometer, bring the sample to exactly 20°C. in a small aluminium dish, stirring with a thermometer graduated in fifths or tenths, use the thermometer bulb to transfer the sirup to the prism and then immediately take several readings, bringing the shadow region to the cross lines alternately from above and below. Operating in this way, he finds that his staff agrees in independent readings of the same sample within 0.20 per cent of water and, except for very dark solutions (molasses, etc.) or those that are turbid, he would take this as the maximum allowable amount of deviation from the middlemost result. In Table 1 the results which would be rejected on this basis are printed in italics. In view of the considerable variation between the results of C and F and of P, Q, R and S on identical portions of the sample, there can be little doubt that greater attention should be paid to precision in temperature control. PREPARATION OF SAMPLE. Collaborators were instructed to study the following proposed revised directions and to compare them with the present tentative method: (a) Maple sirup—Determine the moisture according to 10+. If sugar has crystallized out, redissolve it by warming. Shake up any sediment that remains and pour a suitable quantity for analysis (about 100 cc. for all determinations) into a casserole or beaker. Add one-fourth the volume of distilled water. (The advisability of neutralizing with ammonia at this point might well be studied at some future time.) Boil to a temperature of about 104°C. (219°F.). Filter the hot sirup through a plug of cotton wool in the point of a funnel. After cooling, redetermine the moisture according to 10+. (b) Maple sugar and other solid or semi-solid products —(The present report refers to sirup alone. The moisture method for maple sugar may best be made identical with that for some of the other saccharine products, bearing in mind that maple sugar sometimes contains considerable invert sugar.) Determine moisture in the sample in 1 Assoc. Official Agr. Chemists, Methods, 1916, 126. 430 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 its original condition after thoroughly mixing. For all other determinations, prepare a sirup from about 100 grams of the material by dissolving in about 150 cc. of hot water, boiling to a temperature of 104°C. and filtering through cotton wool as in (a). After cooling, determine the moisture in the sirup according to 10. A few experiments were made by Van Zoeren and the writer on the relative rate of filtration of the hot sirup through cotton wool and through filter paper. Eimer and Amend’s “best white’, Whatman No. 4 and Carl Schleicher and Schiill’s No. 597 papers were used. In all cases, the filtration was very much slower than through the cotton wool. The other collaborators all chose to prepare their samples by the cotton- wool method. This seems to be the most satisfactory method in the field and it is, therefore, recommended that the above directions be adopted in place of the present tentative method. Valin in 1918 reported results on the unprepared samples, as well as on the samples prepared according to the proposed revised directions. WINTON LEAD NUMBER. Collaborators were instructed to prepare and analyze basic lead acetate solutions of specific gravity 1.25 (a) from Horne’s lead subace- tate, (b) from litharge and lead acetate, following the directions given below, and to use these two solutions comparatively in the Winton method and also in the Canadian lead method. PREPARATION OF BASIC LEAD ACETATE SOLUTIONS. (a) From Horne’s lead subacetate—Boil 280 grams of Horne’s lead subacetate with 500 ce. of water. When solution is complete except for a slight sediment, allow to cool in the dish or pour off into a Pyrex beaker. Take the sp. gr. at 20°C. and dilute with recently boiled water to a density of 1.25. (b) From litharge and lead acetate—Weigh 215 grams of normal lead acetate crystals and 65 grams of litharge into a 1-liter evaporating dish. Add about 500 cc. of water. Heat to boiling and boil exactly 30 minutes. Allow to cool in the dish or pour off into a Pyrex beaker. Dilute to a density of 1.25 at 20°C. as in (@). DETERMINATION OF THE ALKALINITY OF LEAD SUBACETATE SOLUTIONS. Pipette 10 cc. of the solution (sp. gr. 1.25) into a small beaker or Erlenmeyer. Add exactly 50 cc. of N/2 oxalic or sulphuric acid. Mix and allow to stand until the precipi- tate is well settled. Filter into a 250 cc. volumetric flask, washing the precipitate thoroughly with water. Make up to the mark and titrate 50 cc. aliquots with N/10 sodium hydroxid, using phenolphthalein. Half the difference between 50 and the number of cc. of N/10 sodium hydroxid used represents the number of cc. of N/10 sulphuric acid neutralized by 1 cc. of the lead subacetate solution. DETERMINATION OF TOTAL LEAD IN THE LEAD SUBACETATE SOLUTIONS. Pipette 5 cc. of the solution into a 250 cc. flask. Add sufficient acetic acid (about 1 ce. of 30% or 5N acid) to prevent precipitation on diluting, and make up to the mark. Treat 25 cc. aliquots with 25 cc. of water and 1 cc. of dilute sulphuric acid (if 5N, or 1921] SNELL: REPORT ON MAPLE PRODUCTS 431 2 cc. if 2N). Mix, add 100 ce. of 95% alcohol and allow to stand 3 hours or more. Filter on a tared Gooch, wash with alcohol, dry in an oven and ignite to bright redness in a muffle. Cool and weigh. Multiply the weight of the precipitate by 1.3665 (ex) to obtain the weight of lead per cc. of solution. CALCULATION OF THE RATIO OF NEUTRAL TO BASIC LEAD. Multiply the alkalinity of the solution (expressed in cc. of N/10 acid) by 0.01036 (tam) . The result represents the basic lead per cc. The difference between the total and the basic lead represents the neutral lead per cc. Calculate the ratio of neutral to basic lead to the second decimal place. The results of the analyses are shown at the foot of Tables 5 and 6 (Canadian lead numbers). It will be seen that Horne’s salt yielded solutions a little more variable in lead content but much more uniform in basicity than the litharge and lead acetate. The extreme variations among the five collaborators were: Range of variation in composition of basic lead acetate solution. RATIO OF NEUTRAL TO BASIC LEAD SOLUTION TOTAL LEAD grams per cc. PORTIS ISISALUM I Aone Cys ea ey sea Sviete oe 0.214—0.237 1.50—1.83 fitthargejand lead acetate s....j:\svar- - Ricuckeis sts1s)<12.2 «loses 0.215—0.233 1.33—2.75 The results of the Winton lead determinations are given in Tables 2 and 3, the figures being averages of duplicate results. The acetic acid blank was used in calculating these results. The blanks in which a cane sugar sirup was used in place of the acetic acid did not differ materially from the acetic acid blanks. It will be noted that, although the differences are small, the solution prepared from Horne’s salt gives a higher average result on six of the seven sirups. With the following six exceptions, all of the thirty-five results obtained by the individual collaborators on individual sirups are higher with Horne’s salt solution than with that prepared from litharge and lead acetate: Valin, Sample 4, both prepared and unpre- pared; Van Zoeren, Samples 4 and 6; and McFarlane, Samples 3 and 6. As will be seen by reference to Table 6, the solutions prepared from litharge and lead acetate by Van Zoeren and McFarlane were excep- tionally basic, having (at the density 1.25) ratios of neutral to basic lead lower than Horne’s salt solutions made and analyzed by the same collaborators. It may also be noted that all three sirups in question (Samples 3, 4 and 6) were adulterated sirups. Were it not that results in the opposite direction were obtained by Bryan! with a similarly pre- 1U.S. Dept. Agr. Bull. 466: (1917), 10. 432 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 pared litharge-lead acetate solution, it might be concluded that in general the 1.25 solutions prepared from Horne’s lead subacetate have ratios of about 1.50 to 1.75 and, when diluted, give slightly higher Winton num- bers than those prepared from litharge and lead acetate, which normally (at a density of 1.25) have over twice as much neutral as basic lead. For Bryan’s similarly prepared litharge-lead acetate solution (his No. 5) the writer calculates the ratio of neutral to basic lead as 1.11. In five out of six pure sirups this gave slightly higher results than a more basic Horne’s salt solution (his No. 4; ratio 1.14). In the course of the work on the Winton lead method it was observed by Van Zoeren and the writer that when the filtrate from the lead subacetate precipitate was allowed to stand for a few days it became turbid. This suggested that results might be affected by unduly extend- ing the interval between precipitation and filtration. The results shown in Table 4 indicate that error may arise from this source but the effect of time intervals of more reasonable length has not been investigated. CANADIAN LEAD NUMBER. Weigh the quantity of sirup containing 25 grams of dry matter, transfer to a beaker, add 50-75 cc. of water, boil gently for 2-3 minutes, transfer to a 100 cc. flask, cool and make up to the mark. Pipette 20 cc. of this solution into a large test tube, add 2 cc. of lead subacetate solution (sp. gr. 1.25) and mix. Allow to stand 2 hours, filter through a tared Gooch, having an asbestos mat at least 3 mm. thick, wash four or five times with boiling water, dry at 100°C. and weigh. Multiply the weight of the dry precipitate by 20. In the collaborative work of 1917, it was noted that Valin obtained lower results on all sampels than did Van Zoeren and the writer. After the report was completed, an interchange of solutions was made between the two laboratories and the following results obtained: Comparison of Canadian lead numbers obtained in 1917 with different solutions of basic lead acetate. CANADIAN LEAD NUMBERS ALKALINITY SOLUTION cc. N/10 ACID PER CC. OF SOLUTION A. O. A. C. 1917 Sirup Another No. 2 sirup Valin Snell Valin Litharge-lead acetate, 1915*.......... 7.40 3.19 3.42 1.94 Litharge-lead acetate, 1917*.......... 8.60 Porte rers: Pee lorne’'s salt fi argon «a: cisions eareenins Sse oT 8.72 Bao 3.75t 2.29 3.84§ * Prepared in Food and Drugs Laboratory, Inland Revenue Department, Ottawa, Canada. + Result obtained in October. t Prepared in Macdonald College Laboratory, Macdonald College, Quebec, Canada. § Result obtained in December. 1921] SNELL: REPORT ON MAPLE PRODUCTS 433 This indicated that higher lead numbers might be obtained the more alkaline the basic lead solution. This indication is strikingly confirmed in the results tabulated in Tables 5 and 6. All except two of the collabo- rators invariably obtained higher results on each sirup when they used Horne’s salt solution than when the other solution was employed. The exceptions were Van Zoeren, whose very basic litharge-lead acetate solution gave higher results in five instances out of six than his Horne’s salt solution, the results being equal in the sixth instance; and McFar- lane, whose two subacetate solutions were nearly equal in ratio and whose results are divided, four to three. A notable feature of Tables 5 and 6 is the wide divergence between the results of the different collaborators and even in different series of experiments by the same investigator. This is still more clearly brought out in Table 7. Results, (F), by A. G. Woodman (Massachusetts Insti- tute of Technology, Boston, Mass.), are without exception the highest or second highest, and Valin’s results on the prepared sirup in 1918, (A), the lowest or second lowest. With Horne’s solution Valin’s 1919 results, (B), are high throughout and McFarlane’s, (D), low. Valin’s 1918 results on the unprepared sample, (G), and the writer’s, (E), are always near the middle or average. Van Zoeren’s results, (C), with the litharge- lead acetate solution are among the highest, a result which might be attributed to the very high basicity of his solution had not Woodman, with the least basic solution of all, obtained results equally high. Wood- man sometimes allowed his solutions to stand more than the prescribed two hours but Valin states that overstanding does not render his results high. Evidently, there is some unrecognized condition affecting the Canadian lead number. Valin (Column H) made some experiments with a modifi- cation of the Canadian Jead method in which 5 cc. of a solution, made by diluting one volume of the specific gravity 1.25 solution of basic lead acetate to five volumes, were used in place of the 2 cc. of the 1.25 solution and the time of standing was extended to 3 or 4 hours. In these experi- ments, not only were the precipitates weighed but the unprecipitated lead in the filtrate was also determined, as in the Winton method, the object being to ascertain whether the variations between duplicates in the Canadian lead method might not be due to variations in the washing of the precipitates. In spite of the fact that the quantity of lead used in these experiments per gram of dry matter was only half as much as in the regular Canadian method, the lead numbers found (Tables 5 and 6, Column H) were close to those obtained by the regular method and the differences between the results obtained with Horne’s and litharge- lead acetate solutions were practically the same as in the regular Cana- dian method. 434 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 The quantity of lead contained in 5 cc. of the diluted Horne’s solution was 0.234 and that in the litharge-lead acetate 0.230, being close to the amounts found in 1 cc. of the 1.25 solutions. The percentages of these quantities of lead remaining in the filtrate from the lead precipitates are shown in Table 8. The maximum difference in the quantities of lead found in the filtrates from duplicates was 1.30 per cent, corresponding to a difference of 3 mg. of lead. Valin infers that the differences between duplicates are not due to the washing but to the actual amount of precipitate produced by the reagent. ASH VALUES. The ash values as found by three of the collaborators are given in Tables 9 and 10. The figures of Valin and McFarlane are averages of satisfactory duplicates (except Valin’s alkalinities, which appear to be single determinations); the averages of the writer are of three or four measurements, some made in 1918, the others in 1919. The agreement among collaborators is closer on the ash values than on any of the other determinations. ; In the Macdonald College Laboratory it is the custom to ash over an Argand burner until charring is complete, then transfer to a muffle. When the carbon is nearly all burned out, the dish is removed from the mufile, allowed to cool, the ash moistened with 0.5 to 1.0 cc. of water, evaporated to dryness and returned to the muffle. The moistening appears to facilitate the ashing and also diminishes the danger of mechan- ical loss of the fluffy ash. When the carbon is all burned out, it is allowed to cool again, about 0.1 gram of solid ammonium carbonate added, moistened with water, evaporated to dryness and heated gently in the muffle for 1 to 2 minutes. In treating the insoluble ash, the cooled ash is moistened immediately after ignition over the flame, so as to provide against mechanical loss of the light filter ash in transferring to the muffle. In the alkalinity determinations, methyl red is used in place of methyl orange. MALIC ACID VALUE. Malic acid value was determined by the Cowles method. The results, as given in Table 11, show wide variations, the writer’s results being generally high and Valin’s low, while those of the two other collaborators are distributed. McFarlane and the writer both warmed the solutions during standing. McFarlane adhered to a definite volume of wash alcohol; the writer did not. A blank determination was used by the writer but not by McFarlane. With Sample 1, the writer experimented with four solutions of calcium acetate which were made from two sam- ples of calcium acetate (Merck’s “dry” and Baker and Adamson’s, 1921] SNELL: REPORT ON MAPLE PRODUCTS 435 labelled Ga (C2H;0:)2 2H,O, but approximating closely to Ca (C2H;O2)2 H,0 (theory 31.84 per cent of calcium oxid; found 31.97 and 32.04 per cent; average 32.01 per cent) and varied slightly in concentra- tion. Although individual results varied from 0.74 to 0.94, the varia- tions did not appear to be related to the make-up of the solutions. In some instances, the precipitate was ignited and weighed (sometimes both as calcium oxid and as calcium carbonate), as well as titrated. The gravimetric results were always higher than the volumetric, but it was evident from the color that the ignited precipitates were not pure cal- cium compounds. A pair of determinations made with calcium chlorid, instead of calcium acetate, gave 0.72 and 0.71 (uncorrected for blank), as compared with the average of 0.86 obtained with the acetate. The procedure followed was the same with both salts. In the original malic acid value method of Leach and Lythgoe! the chlorid was the calcium salt used, and its use was retained by Hortvet? in adapting the method to maple products. In his extensive work on pure maple sirups, Bryan® used both the Cowles method and a modifi- cation of the Hortvet method in which blanks were run. The range of variation of the value was narrower with the Hortvet method than with the Cowles, 0.29 to 1.60 as against 0.21 to 1.82; in other words, a range of 452 per cent of the minimum value (156 per cent of the average, 0.84) for the Hortvet method as against 767 per cent of the minimum (159 per cent of the average 1.01) for the Cowles method. Calcium chlorid has also the advantage that if incompletely washed out it will not affect the alkalinity of the ash of the precipitate. In spite of the preference of Cowles and Bryan‘ for the acetate, it seems to the writer possible that a method might be worked out with the chlorid, which would give results more consistent than those so far obtained with the Cowles pro- cedure. In its present form, the latter is certainly not a satisfactory method. Pozzi-Escot’s suggestion® to substitute an alcoholic solution of barium bromid for the calcium salts is worthy of consideration. CONDUCTIVITY VALUE. Determination of the cell constant.—Prepare 0.1, 0.02 and 0.01 molar potassium chlorid solutions by dissolving respectively, 7.4560, 1.4912 and 0.7456 grams of pure, ignited potassium chlorid in water and making up to 1000 cc. at 18°C. In a 100 cc. beaker place 60 ce. of the 0.01 molar solution, insert a Van Zoeren or other dipping electrode, bring to 25°C. and measure the electrical resistance. Multiply the number of ohms found by 141.2. Rinse the electrode and beaker with the 0.02 molar solution, put in 60 ce. of this solution, measure its resistance at 25°C. and multiply by 276.8. Rinse 1 J. Am. Chem. Soc., 1904, 26: 380. 2 Ibid., 1536; U.S. Bur. Chem. Bull. 107, rey.: 1912, 74. 3U.S. Bur. Chem. Bull. 134: 1910, 18. 4 J. Am. Chem. Soc., 1908, 30: 1285; U.S. Dept. Agr. Bull. 466: (1917), 11. 5 Bull. assoc. chim. dist., 1908, 26: 266. 436 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 with the 0.1 molar solution, put in 60 cc., measure its resistance at 25°C. and multiply by 1289. Average the three results (which should agree within 1 per cent) and multiply by 10-5. Method.—W eigh out the quantity of sirup containing 22 grams of dry matter. Transfer to a 100 cc. volumetric flask with warm water, cool and make up to the mark. Measure 60 ce. of the solution into a 100 cc. beaker, insert a Van Zoeren or other dipping elec- trode, bring to 25°C. (+0.1°) and measure the electrical resistance. Divide the con- stant of the cell by the observed number of ohms and multiply the result by 10°. The test was applied to the samples, both in the above form and in the form previously published, in which 20 ce. of the prepared sirup were measured out with a graduate into a 100 cc. beaker and the grad- uate rinsed with two successive portions of 20 cc. of water. Except in Sample 1, closer agreement between collaborators was obtained by using the more exact method, 1. e., making solutions containing exactly 22 grams of dry matter to 100 cc. (See Table 12.) This test is so simple, so rapid and so useful that it may well be recom- mended to the association for adoption. RECOMMENDATIONS. It is recommended— (1) That the directions for “Preparation of Sample’’? be amended to read as follows: 53 PREPARATION OF SAMPLE.—TENTATIVE. (a) Maple sirup—Determine the moisture by one of the methods given under 54(a). If sugar has crystallized out, redissolve it by warming. Shake up any sediment remaining and pour off into a casserole or beaker a suitable quantity for analysis (100 cc.). Add one-fourth the volume of distilled water. Boil to a temperature of 104°C. Filter hot through a plug of cotton wool in a funnel. After cooling redetermine the moisture according to 54(a) and use the result to reduce the other values determined to the dry substance basis. (b) Maple sugar and other solid or semi-solid products —Determine moisture by one of the methods given under 54 (b) after thoroughly mixing the sample. For all other determinations prepare a sirup from about 100 grams of the material by dissolving in about 150 cc. of hot water, boiling to a temperature of 104°C. and filtering through cotton wool as in (a). After cooling determine the moisture in the sirup according to one of the methods of 54 (a). (2) That in the tentative method for the determination of moisture, 54 (a)*, the refractometer method, 10°, be given the preference and that the other method to be recommended in 54 (a) and (b) be decided upon by the referee on saccharine products. (See Report of Associate Referee on Maple Products 1917+.) 1 J. Ind. Eng. Chem., 1916, 8: 331. ? Assoc. Official Agr. Chemists, Methods, 1916, 136. 3 Ibid., 126. 4 J. Assoc. Official Agr. Chemists, 1920, 4: 157 1921] SNELL: REPORT ON MAPLE PRODUCTS 437 (3) That the tentative method for total ash! be amended to read as follows: Heat 5 grams of the prepared sirup over a low flame (an Argand burner is recom- mended) until completely charred. Transfer to a mufile and heat at low redness (not over 550°) until a white ash is obtained. (If desired, the ashing may be interrupted when the carbon is nearly all burned, and after cooling, 0.5-1.0 cc. of water may be added and evaporated.) After cooling, add about 0.1 gram of ammonium carbonate, free from non-volatile matter, and add 0.5-1.0 cc. of water. Evaporate to dryness and reheat in the muffle for 1-2 minutes. Cool in a desiccator and weigh. (4) That the Canadian lead method be adopted as a tentative method with directions as follows: CANADIAN LEAD NUMBER.—TENTATIVE. REAGENT. Standard basic lead acetate solution.—Boil 280 grams of Horne’s lead subacetate with 500 cc. of water. When solution is complete except for a slight sediment, pour off or allow to cool and dilute with recently boiled distilled water to a density of 1.25 at 20°C. DETERMINATION. Weigh the quantity of prepared sirup (IX, 532) containing 25 grams of dry matter, transfer to a 100 cc. volumetric flask, cool to 20°C. and make up to the mark. Pipette 20 cc. into a large test tube, add 2 cc. of the standard basic lead acetate solution and mix. Allow to stand 2 hours. Filter on a tared Gooch, having an asbestos mat at least 3 mm. thick, wash four or five times with boiling water, dry at 100°C. and weigh. Multiply the weight of the dry precipitate by 20. (5) That the caption above IX, 63! be amended to read, “Winton Lead Number.—Tentative’’. (6) That in IX, 65, line 3!, the words “‘at least” before “3 hours’ be omitted. (7) That the conductivity value method, as given on page 435, be adopted as a tentative method. KEY TO OBSERVERS. I. Using Abbé refractometer: A. Woodman, 1918. B. Valin, 1918. C. Snell, 1918. O. Woodman, 1919. 1 Assoc. Official Agr. Chemists, Methods, 1916, 137. 2 [bid., 136. 438 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 II. Using Féry refractometer: Van Zoeren, 1918 Miss Dorothy Moule, Macdonald College, Quebec, Canada, 1918. Snell, 1918. Snell, August, 1919. McFarlane, August, 1919. Snell, September, 1919. McFarlane, September, 1919. fdentical samples—C and F. Identical samples—P, Q, R and S. nPOO Aho TABLE 1. Moisture in original samples, determined refractometrically*. SAMPLE 1 | SAMPLE 2 | SAMPLE 3 | SAMPLE 4 | SAMPLE 5 | SAMPLE 6 | SAMPLE 7 per cent per cent per cent per cent per cent per cent per cent Maximum..... O 43.06+| O 32.40 | O 33.80 | Q 34.27 | E 33.70 | E 32.70 | Q 35.62 D 43.04 | A 32.30 | F 33.64 | A 34.15 | D 33.57 | A 32.36 | F 35.39 F 42.79 | P 32.23 | D 33.47 | R 34.15 | 0 33.50 | C 32.31 | D 35.37 A 42.75 | R 32.23 | E33.35 | S 34.10 | R 33.34 | R 32.28 | C 35.32 P 42.58 | D 32.12 | C 33.33 | D 34.03 | C 33.27] ..... |] ..... Middle....... E 42.50 | F 32.06 | P 33.17 | C 34.00 | A 33.20 * Assoc. Official Agr. Chemists, Methods, 1916, 126. t+ The panoed readings differ from the middle readings by more than 0.20, the limit adopted by Main (see page 429) 7 Sam ple 3 was difficult to read in the Féry refractometer. TABLE 2. Winton lead numbers, dry basis, using Horne’s sall solution. UNPREPARED PREPARED SAMPLES SAMPLES SIRUP NUMBER SS eS) So ee ae ene tt eiee Valin Van Zoeren| McFarlane Snell Valin Diy Gea doe eee 2.06 2.70 2.65 2.33 2.19 2.39 Dis castrar ste carats aetoetalets 2.50 2.85 3.10 2.66 2.56 2.73 BN Mean Se Sitesi 1.93 2.87 2.29 2.33 2.06 2.30 Beets Drake aS ISTIC SM 1.96 2.14 2.59 2.09 1.76 2 eae Sete cere ae 2.42 2.70 2.42 2.50 2.33 2.47 Gees ee AP oe 2.00 2.65 2.37 2.14 2.09 2.25 Lid Cis ORG ate a Te 2.50 2.93 2.52 2.79 2.51 2.65 Acetic blank, grams lead sulphate........ 0.170 0.1697 | 0.1652 | 0.1692 0.170 Sugar blank, grams lead sulphate........} 0.171 0.1666 | 0.1667 | 0.1683 0.171 a a i 1921] TABLE 3. SNELL: REPORT ON MAPLE PRODUCTS 439 Winton lead numbers, dry basis, using litharge-lead acetate solution. PREPARED SAMPLES SIRUP NUMBER Valin Van Zoeren McFarlane on Se ee 2.05 | 2.63 2.46 FA iy ee ee sO cto. 2.36 2.78 2.33 Sj 8 ee ere ae 1.89 2.84 2.62 Ch Cea GRC > Cater eo 2.12 ZAD | 2:01 (7p SR re Bin Ae bags 2.07 2.67 | 2.35 Cree avec sae } 1.85 2.67 | 2.44 pr ee lege | gee: 9) as Acetic blank, grams lead sulphate........ 0.168 0.1693 | 0.1611 Sugar blank, grams } | lead sulphate........ 0.167 | 0.1686 0.1613 TABLE 4. UNPREPARED SAMPLES AVERAGE Snell Valin 2.21 2.18 2.31 | 2.54 2.46 2.49 2.30 1.93 2.32 1.92 1.81 2.06 2.34 2.14 2.31 1.98 1.92 2.17 2.56 2.29 2.50 0.1708 | 0.168 0.1697 | 0.167 Effect of overstanding of lead precipitate in Winton determination. SIRUP NUMBER Spee Sea Siena or ooEe TIME OVERHELD WET BASIS HELD SOLUTION weeks 3 Litharge 1.56 1.70 4* 3 Horne’s 1.58 1.91 4 4 Litharge 1.23 1.41 4* 4 Horne’s 1.34 1.76 4 5 Litharge 1.53 1.87 4 5 Horne’s 1.63 2.02 4 * Days. TABLE 5. Canadian lead numbers, using Horne’s sali solution. PREPARED SAMPLES eas MODIFIED SAMPLEs | METHOD SIRUP NUMBER c D Fr A B : E SET a fp ees) es Pale Valin | Valin 1918 1919) 1) Sais 1910 1918 Taig 1918 1919 1 RS OE ee 2.62 3.41 3.31 3.01 3.35 4.04 3.16 3.46 DUE aie cle Stee ayes 2.80 3.75 3.62 3.23 3.62 4.37 3.64 3.93 peice ctceic are ccs 6 2.56 3.44 | 3.66 2.85 3.23 4.13 3.39 3.31 BEN Sys fate) eP airev os = 2 2.30 2.87 2.77 2.31 2.69 3.38 2.79 3.05 eee a ore he cs asic Shy 3.92 3.51 2.57 3.48 4.11 3.63 3.72 Uni 5 eee 2.36 3.11 eer, 2.75 2.81 3.30 2.89 3.20 1 (5p go 3.17 4.03 3.16 } 3.31 3.69 4.77 3.85 3.62 Alkalinity....... 8.69 8.95 8.55 | 8.10 8.51 7.48 8.69 eee Lead per cc...... 0.223 | 0.232 | 0.2329) 0.237 | 0.2337) 0.2144) 0.223 Ratio of neutral lead to basic {EEG Ite ae ee 1.58 1.50 1.63 1.83 1.65 1.76 1.58 I t | 440 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 3 TaBLe 6. Canadian lead numbers, using litharge-lead acetate solution. MODIFIED | BBSRBSR : : UNPRE- PARED SAMPLES | METHOD PREPARED SAMPLES hOnonnnms AONRIONNOHION NM CON ON OOO 2.24 1D DDIM AATAN OO HS eH OI OD 6D CD NI OVD 0D 01D 1 Br) ror) CAM OMONNMA Rgomnanrinon NOD OO NI OO NOD Ik © 2.75 2.01 wD MnO O09 Din RAAMAOOHN NON N 6D ODN I~ © 1.78 Slab SeeBH OOD COON ODN OD OO 1.33 2 yO O1DONIDrN Dato tH™~ COON NMAN ON OD OO S Oy NOSMN oD oD MOMMA ORMM™~ ON NANNNNN OO SIRUP NUMBER Lead per cc. Ratio of neutral lead to basic er * In making up this solution, Van Zoeren added an old solution to the water with which he boiled the litharge and lead acetate. TABLE 7. Canadian lead numbers, arranged in order of magnitude. bd ™~ al ive) P RS8)S) RAF 1s HOS || FSR | = P stictiod | od | odes | A eded | od | ONAN | A a BOAO) )/Ado OnM ||) oad © oO Inc | H o|Nhoo Fi RAH Biss | & 6A | |RSS |B P on Oo NN Aaa |S OMAILA | ANN | A a fa FO pad Amo | )mo< vr N oD Lind i (Je) © ind w a8 || S45 |B Ros] 4/843 |S P soso | od | MOON | moo len | MON |S mi BMAO}O }m@A0 BOM |)O)hA4 a! Ot D> ~ [or =) io,0) Om~o ve) Doo > COM | | ON 1 O ireretesch |) etl Merltop iad tz P BAN! A | ANN] A NAAN | A | ANNA | oOo i meAo)|O)HAd BOO! | mA 9 oh co a | minw |r mon] a | con|o fe] ACS 2] NO! | 4 Le ei tural beet | Ir acta ar) Ay stosed | od | AN | ones | od | NN | 4 mom |o | wae one |a |ama N rot AT AMO | MO | oy | Oth | a 4 CAIN | DO | OND | 19 A Sr al frst WO: [Rag Pa ad P soded | os | oma | a enenes | on | coo | a Boo}; | oad BOM | M | oad = tH run re Onn ios] Dit co I> Ot i y SS Cen Oa || re Oe Ise HOPI PN iC Nal ool CH ig P sodas | od | HON | MOANA LANN |S rs BAB )O)oAd ORO | |/mAd foe ; aes eee p Tale ‘® : : : | bo : i ; . « ee . 0 A E| :|3e8 oe Balers CS} 2 Blolse a 8] o co: | | bo | 9: a | Ee 3 2|8| vos = | 3 ga a 2lal- se = a |e ~ ~ 1921] SNELL: REPORT ON MAPLE PRODUCTS 441 TaBLe 8. Modified Canadian lead method—study of duplicates by A. Valin. CANADIAN LEAD NUMBERS TOTAL LEAD LEFT IN FILTRATE SAME NEMBES. | Using Horne’s Ligieyetoed Using Horne’s ree salt acetate salt acetate per cent per cent i ee ae 3.50 2.96 50.85 56.95 3.44 3.02 51.28 55.65 Average..... 3.47 2.99 Difference... . —0.43 1.30 Eee, wekalie (aie sia eS AT 60°F. | | | | | | | | z per cent | per cent per cent per cent — 0°C. Holstein milk*.......... | 1.0292 1S os)! 2916 7.8 0.94 0.545 | | | < | 14.51 | Composite sampley...... | 1.0296 5.8 * First portion drawn from udder, representing only a partial milking. Contains no added water. + Complete milking from four Jersey cows. Supposed to contain 5 per cent added water. The practical application of the freezing-point determination is further illustrated by the results (Table 4) of tests made on samples of known- pure milk to which various percentages of water were actually added. It is important to bear in mind the fact that the freezing-point result obtained on a sample of milk containing a known amount of added water will depend largely upon the freezing-point test of the original whole milk. For example, in the case of two milks, each known to con- tain 10 per cent added water, very different results may be obtained, depending upon whether the freezing point of the original milk registered in the neighborhood of —0.540° or somewhere near —0.560°. The narrow range in freezing-point variations, therefore, makes it necessary in esti- mating percentages of added water to take into account a correction factor which may fairly be given as approximately 2 per cent. Tables 5 and 6 give the results of analysis of two samples of milk drawn from Holstein cows. One showed a fat content of 3.1 per cent, as well as a very low specific gravity, and solids and ash content. The general composition of the other sample was practically the same, except for the butter fat, which was very low, viz, 1.8 per cent. Judged by ordinary rules, both of these samples might be suspected of adulteration with water. Information accompanying the samples was to the effect that each had been obtained as the first portion drawn from the udder of the cow (about one pint in both instances), representing only a partial milking; in other words, that portion of the milking which would be 498 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 discarded as not constituting a representative whole milk. Nevertheless, on application of the freezing-point test to these samples very normal results were obtained, in the one case —0.543° and in the other —0.544°. Thus it appears that the freezing-point test indicates freedom from added water in both samples, while the ordinary analytical results lead to a suspicion that they are adulterated by means of added water. The other two samples included in Tables 5 and 6 were obtained from Jersey cows. In each of these samples the content of butter fat and total solids is very high, the other values being correspondingly fairly normal. So far as the analytical results can indicate there is nothing abnormal in the composition of these milks, but the results of freezing- point tests indicate substantial amounts of added water, in the one instance approximately 12 per cent and in the other over 6 per cent. RECOMMENDATIONS. Practical results obtained by many investigators show that the cryo- scopic method is dependable as a means of determining, with a reason- able degree of accuracy, percentages of added water in milk. As a result of a careful study of this question during the past two years and after an extensive amount of experience with the application of the freezing- point method to a large variety of samples of market milks, as well as milks of known origin and composition, it is reeommended— (1) That this method, to be known as the cryoscopic method for the determination of added water in milk, be adopted as a tentative method by this association. (2) That the cryoscopic method for the determination of added water in milk be subjected to further study with a view to its adoption as an official method. If these recommendations are adopted in the manner suggested above, a plan of collaborative work can be arranged which will aim to serve the following purposes: (1) To confirm the reliability of the cryoscopic method as a means of determining percentages of added water in milk. (2) To develop and standardize the essential details in carrying out the determination. (83) To arrive at definite conclusions regarding error factors and necessary corrections to be applied under various conditions. (4) To perfect the details of a standard experimental outfit to be devised for the purpose of making freezing-point determinations on samples of milk, milk products and other food products to which the cryoscopic test may be applied. ee 1921] HOAGLAND: REPORT ON MEAT PRODUCTS 499 REPORT ON MEAT AND MEAT PRODUCTS! By Raxtex Hoacranp (Bureau of Animal Industry, Washington, D. C.), Referee. The official methods for the examination of meats and meat products which were adopted by the association in 1916? are very much in need of further revision in order to bring them up to date. For several reasons such a revision proved to be impracticable. Because of personal interest in two methods, however, the referee undertook a study of: (1) A method for the determination of sugar in meat; and (2) a comparative study of two methods for the determination of moisture in meat. A report of the work follows: STUDY OF THE PHOSPHOTUNGSTIC ACID METHOD FOR THE ESTIMATION OF DEXTROSE IN MEAT. The following method, which has been used successfully by the referee for several years, was sent out to a number of chemists for cooperative work. Reports were received from four. ESTIMATION OF TOTAL SUGAR. REAGENTS. Phosphotungstic acid.—Dissolve 100 grams in water, and make up the solution to 100 ec. PREPARATION OF WATER EXTRACT. Weigh 100 grams of the finely ground sample into a 600 cc. beaker, add 200 ce. of water, heat to boiling, and boil gently for 5 minutes. Stir the contents of the beaker frequently during this and subsequent extractions to prevent bumping. When several samples are extracted at the same time a mechanical stirring device is practically a necessity. Remove the beaker from the flame, allow the insoluble matter to settle, and decant the clear liquid on an asbestos mat in a 4-inch funnel. Filter with the aid of suction. Add 150 cc. of hot water to the residue in the beaker, boil gently for 5 minutes, let settle, and decant the clear liquid as before. Repeat the operation, and finally trans- fer the contents of the beaker to the funnel, wash with 150-200 cc. of hot water, and press the meat residue as dry as possible. Transfer the contents of the filter flask to an evaporating dish, and evaporate on a steam bath to a volume of about 25 cc., but not to dryness. Transfer the extract to a 100 cc. volumetric flask, taking care that the volume of liquid does not exceed 60 cc. Add 25-35 ce. of phosphotungstic acid, shake vigorously, let stand a few minutes for gas bubbles to rise to the surface, make to volume, shake, and either filter or centrifugalize. The use of a centrifuge is to be preferred since a larger volume of liquid is obtained. Test a portion of the filtrate with dry phosphotungstic acid for complete precipitation. If an appreciable precipitate forms, take an aliquot portion of the filtrate, add 5-10 cc. of phosphotungstic acid, make to volume, filter, and test the filtrate for complete precipitation. The filtrate should also show not more than a slight reaction for creatinin by Jaffe’s test’. 1 Presented by W. C. Powick. 2 Assoc. Official Agr. Chemists, Methods, 1916, 271. 30.Hammarsten. Textbook of Physiological Chemistry. 1915, 696. 500 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 DETERMINATION. Transfer 50 cc. of the clarified extract to a 100 cc. volumetric flask, add 5 cc. of concentrated hydrochloric acid, and invert by one of the official methods. Cool the solution, neutralize to litmus, cool, make to volume and filter. To the filtrate add enough dry powdered potassium chlorid to precipitate the excess of phosphotungstic acid, filter, test for complete precipitation, and determine the reducing sugar by the method of Munson and Walker’. Estimate the reduced copper by Low’s iodid method?. Calculate the total sugar as dextrose. Table 1 shows the results obtained by the several analysts: TABLE 1. Estimation of dertrose in meat by phosphotungstic acid method. | DEXTROSE | DEXTROSE TOTAL DEXTROSE ERROR RECOVERY ANALYST IN MEAT ADDED DEXTROSE FOUND per cent per cent per cent per cent per cent per cent L. H. Almy, Food Re- 0.178 0.792 0.970 0.880 |—0.09 90.7 search Laboratory, | 0.178 1.361 1.539 1.304 |—0.235 84.7 1833 Chestnut Street, Philadelphia, Pa. Re Hoagland= 2-2-5 ose 0.122 0.177 0.299 0.300 |+0.001 0.122 0.318 0.440 0.428 |—0.012 0.122 0.742 0.864 0.794 |—0.070 0.122 0.980 1.102 1.071 |—0.031 0.122 1.274 1.396 1.335 | --0.061 0.356 0.177 0.533 0.539 |+0.006 — a RFS | SSSS2GGESS AnD | THRNSHOANOWR —) w or for) Oo oO (2) So me oo ivS) lor) - 3 Ss [—) wo _ R. C. Holder, Food Re- | 0.180 0.186 0.366 0.362 |—0.004 search Laboratory, 0.180 0.334 0.514 0.496 |—0.018 1833 Chestnut Street, 0.180 1.038 1.218 1.042 |—0.176 Philadelphia, Pa. W. D. Richardson, Swift | 0.1395 | 0.1947 | 0.3342 | 0.3520 |+0.0178 | 105.1 and Company, Chi- | 0.1457 | 0.3505 | 0.4962 | 0.5038 |+0.0076 | 101.5 cago, Ill. 0.1580 | 0.8178 | 0.9758 | 0.9630 | —0.0128 98.7 0.1580 | 1.0885 | 1.2465 | 1.2803 |+0.0338 | 102.7 0.1580 | 1.4049 | 1.5629} 1.6520 |+0.0891 | 105.7 J. J. Vollertsen, Morris | 0.2625 | 0.1805 | 0.4430 | 0.4612 |+0.0182| 104.1 and Company, Chi- | 0.2373 | 0.3372 | 0.5745 | 0.5566 |—0.0179 98.6 cago, Ill. 0.2373 | 0.7871 | 1.0244 | 0.9580 | —0.0664 93.5 0.2373 | 1.047 1.2843 | 1.2449 | —0.0394 97.0 0.2373 | 1.352 1.5893 | 1.5466 | —0.0427 97.3 These results may be considered as fairly satisfactory, particularly in the determination of the smaller quantities of sugar. The method is much superior to any other method which the referee has been able to find for the estimation of sugar in meat. Additional cooperative work with it undoubtedly will serve to give a higher degree of accuracy. 1 Assoc. Official Agr. Chemists, Methods, 1916, 86. 2 Ibid., 96. 1921) HOAGLAND: REPORT ON MEAT PRODUCTS 501 DETERMINATION OF MOISTURE IN MEAT BY DRYING AT 100°C. AS COMPARED WITH DRYING IN VACUO OVER SULPHURIC ACID AT ROOM TEMPERATURE. Considerable work has already been done along this line, and the following data are offered simply as additional information on the subject. Triplicate samples of the meat were dried in 2}-inch aluminium dishes provided with friction covers to prevent absorption of moisture by the dried samples on weighing. Samples were dried in an electric oven at 100°C. and in 6-inch Scheibler desiccators containing sulphuric acid. The desiccators were evacuated by a Geryk pump which gave a pressure of less than 1 mm. on the manometer next the pump, but a pressure of 4 to 5 mm. inside the desiccator, as indicated in a small manom- eter. The desiccators were rotated frequently during the drying so as to mix the absorbed water with the acid. Weighings were made at 24- hour intervals. In many cases constant weight was obtained on the third weighing or at 72 hours, indicating that the samples were dry at the end of 48 hours. In practically all cases, constant weight was ob- tained at the fourth weighing. Table 2 shows the results obtained. TABLE 2. Moisture content of meat. pnopvcr ee per cent per cent difference LING 0s ee ee ec atone eto 75.66 75.50 —0.16 res neers sc. xcs) gaass ese Scvaieno: 73.50 73.37 —0.13 RUETIPOLAINS™ ete oct cree es tec es 82.68 82.30 —0.38 Galiskidney ewes eis ne he ete 77.61 77.54 —0.07 Knockwurst sausage.............. 55.82 56.16 +0.34 Frankfurter sausage............... 54.34 54.28 —0.06 WGEVGRISBUSARC S..-. 2 5 oie o's dee ceveis se eras 66.55 65.71 - —0.84 The results obtained indicate slightly greater losses by drying at 100°C. than by drying in vacuo. Where a high degree of accuracy is desired, and particularly when fat is to be extracted from the dried residue, the method of drying in vacuo over sulphuric acid is to be preferred. RECOMMENDATIONS. It is recommended— (1) That as soon as means are provided for the prompt publication of the proceedings of the association, a thorough revision be made of the methods for the examination of meat and meat products. (2) That the method for the estimation of sugar in meat, previously 502 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 described, be adopted tentatively in place of the present tentative method!. (3) That one referee and two associate referees on meat and meat products be appointed as at present, but that the work of the associates be not designated. No report on the separation of nitrogenous compounds in meat products was made by the associate referee for the year ending Noy- ember, 1918. REPORT ON THE SEPARATION OF NITROGENOUS COM- POUNDS IN MEAT PRODUCTS. By L. C. Mrrcxetx? (Wilson & Co., Chemical Laboratory, Chicago, IIl.), Associate Referee®. The work outlined by the associate referee consisted of a study of the Schlésing-Wagner method for the determination of nitrates in meat and meat products. As the time was very short, it was decided to limit the study of this method to the determination of nitrates in beef extract. METHOD. PREPARATION OF SAMPLES. Sample A.—A high-grade beef extract, in which no sodium nitrate was used in the manufacture. This beef extract shows no qualitative or quantitative test for nitrates. It was used in the preparation of Samples B, C and D. Sample B.—high-grade beef extract containing 0.1 per cent of added C. P. sodium nitrate. Sample C.—High-grade beef extract containing 0.3 per cent of added C. P. sodium nitrate. Sample D.—High-grade beef extract containing 0.5 per cent of added C. P. sodium nitrate. Sample E—Low-grade beef extract made from cured meats, therefore containing an unknown amount of commercial sodium nitrate. REAGENTS. Ferrous chlorid solution Dissolve nails, tacks, or other small pieces of iron, in con- centrated hydrochloric acid, keeping an excess of iron present until the evolution of gas ceases. This is conveniently done by setting in a warm place a 2-liter Florence flask containing 400 grams of iron and 1 liter of concentrated hydrochloric acid. Close the flask with a stopper containing a Bunsen valve to keep out the air. Keep the solu- tion in 50 cc. glass-stoppered bottles entirely filled. Employ only freshly opened bottles of the reagent for the determination. Standard sodium nitrate solulion—Dissolve 2 grams of C. P. sodium nitrate in 1 liter of recently boiled water. Take 50 cc. (equivalent to 0.1 gram of sodium nitrate) and 1 Assoc. Official Agr. Chemists, Methods, 1916, 278. ? Present address, U. S. Food and Drug Inspection Station, Federal Office Building, Minneapolis, Minn. ? Associate referee for the year ending November, 1919. 1921] MITCHELL: REPORT ON MEAT PRODUCTS 503 determine the amount of nitric oxid as given in the following method. One-tenth gram of sodium nitrate should give 26.36 cc. of nitric oxid at 0°C. and 760 mm. pressure. APPARATUS. Clamp a 500 cc. Kjeldahl flask with a 2-holed rubber stopper to an iron stand. Through one of the holes pass the stem of a 100-125 cc. open-top cylindrical separatory funnel having a glass stop cock and into the other fit a delivery tube leading downward at an angle from the flask into a trough containing water. Terminate the upper end of the delivery tube just below the rubber stopper in the flask, and place the lower end, which is bent slightly upward and covered with rubber tubing, under the surface of the water in the trough, the exit being immediately beneath the mouth of an inverted measuring tube (50 cc. plain eudiometer tube) filled with 40% sodium hydroxid solution. Midway on the delivery tube between the flask and the measuring tube place a short length of rubber tubing and a pinch cock. This pinch cock, however, has proved to be dangerous, and most analysts will find it safer to do without it. DETERMINATION. To 10 grams of the beef extract in a casserole add 30 cc. of boiling water, and stir until thoroughly mixed, Introduce 50 cc. of the ferrous chlorid solution and 50 ce. of 10% hydrochloric acid into the flask, close the stop cock of the funnel, move the end of the delivery tube so that escaping air will not pass into the measuring tube, and boil the contents of the flask until the air is expelled, as indicated by a slight pressure against the fingers when the rubber tubing is compressed after momentary removal of the flame. Place the exit end of the delivery tube beneath the measuring tube. Introduce the beef extract solution into the flask, a little at a time, through the funnel tube, and boil the contents of the flask at intervals to force the nitric oxid gas into the measuring tube. Finally rinse the casserole and the funnel tube with a little boiled water, add the rinsings to the contents of the evolution flask in the manner described, and boil until the nitric oxid no longer passes over into the measuring tube. Calculate the volume of nitric oxid at 0°C. and 760 mm. pressure. One cc. of nitric oxid at 0°C. and 760 mm. pressure is equivalent to 0.0037935 gram of sodium nitrate. Also calcu- late the percentage of sodium nitrate from the volume of nitric oxid obtained from the sample with the volume obtained from 0.1 gram of C. P. sodium nitrate, both being measured at room temperature. RESULTS OF COOPERATIVE WORK. The results of this work expressed as percentage, appear in Table 1. 504 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 TABLE 1. Nitrogen in beef eztract. CALCULATED FROM SODIUM NITRATE - CALCULATED z Sone ED FROM NITRIC OXID ANALYST A B Cc D E A B Cc D E per cent) per cent) per cent) per cent) per cent\| per cent percent! per cent) per cent) per cent W. D. Richard- | None | 0.078 | 0.24 | 0.44 | 0.98 || None! 0.075/ 0.23 | 0.43 | 0.94 son, Swift & Co., Chicago, ill. E. A. Schlesser, | None| 0.09 | 0.27 | 0.45 | 0.98 Ya. Sao), ee eee Wilson & Co., Chicago, Ill. P. Dunne, Wil-| .... | 0.08 | 0.19 | 0.47 sion: (Ge Cio: | | Chicago, Il. | M. Janowsky, | .... | 0.09 | 0.21 | 0.41 | .... Wilson & Co., | Chicago, Il. | } | | R. Hoagland, | None| .... | 0.27 | 0.39 | 0.85 || None} .... | 0.22 | 0.32 | 0.72 Bureau of Ani-| .... | ..-.. 0.23 | 0.41 | 0.92 226)- det 224) 0:20)4 (0:33 G38 mal Industry, | Washington, | DC: H. C. Kershner, | 0.194+| 0.102 | 0.346 | 0.296 | 1.12 || 0.17 | 0.095/0.30 | 0.25 | 0.98 Bureau of Ani- | 0.095 | 0.087 | 0.247 | 0.425) 1.01 || 0.08 | 0.08 | 0.20 | 0.35 | 0.91 mal Industry, | 0.109 | 0.109 | 0.283 | 0.345 | 1.05 || 0.106 | 0.106 | 0.269 | 0.335 | 1.02 Kansas City,}| .... | 0.139 | 0.318 0.554 | 1.08 .... | 0.133 | 0.340 | 0.539 | 1.04 Kans.fi eo Se sont) Oa] eee | OG ae ood |p SHEE * Run with water in trough, the sodium hydroxid becomes too dilute; evidently it contains carbon dioxid. + First two results based on standards using 0.1 gram of sodium nitrate with corrections for vapor pressure. ( 1 ) = vy ————_ * Pp 760 (1 — 0.00367t) (23: OF eel eee ececnios 0.087 gram (G2) eA BIO ES San can searer oo: 0.094 gram (CR GAG Tee ee eS Sle 0.080 gram (4) 22a echaiwcereice eee soe 0.085 gram t Last three Soe onstandards using 0.1 gram of sodium nitrate without correction for yapo pressure. V = PT’ COMMENTS OF ANALYSTS. H. C. Kershner.—The figures are very unsatisfactory and apparently inaccurate, due no doubt to the rushing through of the test. The results on 0.1 gram of sodium nitrate vary beyond reason, the lowest results appearing when the gas evolution was the most uniform. It is not considered fair to the method to place much reliance on these figures, but they might be taken as a sample of what could be expected from operators unfamil- iar with the method and compelled to perform the test without time for finding the proper conditions. No criticisms are made, but the idea of substituting a 300 ec. flask 1921] MITCHELL: REPORT ON MEAT PRODUCTS 505 arises. This size appears ample, and might shorten the time used to expel the air. A 50 cc. funnel was used, as the 100 cc. appeared unnecessary and top heavy. It was found essential to add additional hydrochloric acid after the charge of extract, 10-15 cc. being added. Rubber gloves were also found to be very useful. R. Hoagland.—The results obtained by calculating the percentage of nitrate from the volume of nitric acid at 0°C., 760 mm., are incorrect, since measured quantities cf a standard solution of sodium nitrate yielded only from 80-92% of the theoretical quantity of nitric oxid. When a portion of the standard solution of nitrate was run into the reaction flask after a sample of meat extract, the quantity of nitric oxid liberated was always smaller than that obtained from a like volume of the standard solution run before the meat extract. DISCUSSION OF RESULTS. The results of the first five analysts show an average recovery of 82.6 per cent of the added sodium nitrate when compared with the amount of gas obtained from a standard nitrate solution. Two of the analysts show 69.4 per cent average recovery when calculated from nitric oxid at 0°C. and 760 mm. The only explanation the associate referee can offer for the wide variation in the results obtained by the last analyst is that either all the air had not been driven from the flask before the extract was added or the apparatus was not air tight. From 0.1 to 0.19 per cent of sodium nitrate is reported in Sample A which was prepared from fresh (not cured) meat, and a negative qualitative test for nitrates is shown. The following modifications are suggested for future work on this method: APPARATUS. (1) That a 40% solution of commercial sodium hydroxid be substituted for the water used in the trough so that the carbon dioxid may be effectively absorbed. (2) That just after “into a trough containing water’, the following be inserted, “The lower end of this delivery tube, should be slightly constricted.” (3) That beginning with ‘‘midway on the delivery tube, etc.”’, to end of paragraph, be deleted. DETERMINATION. (1) That ‘‘Calculate the volume of nitric oxid at 0°C. and 760 mm. * * * is equivalent to 0.0037935 gram of sodium nitrate’’ be deleted. Ccmparing the volume of nitric oxid found with the volume obtained from a known weight of pure sodium nitrate serves as a check upon the method, and the results reported indicate that this method gives a more accurate basis for calculation. (2) That at the end of the method the following be added: “This is conveniently done by transferring the measuring tube to a tall jar containing a 40% sodium hydroxid solution (commercial). The temperature of the surrounding caustic solution will soon (10-15 minutes) be imparted to the contents of the tube, and the volume of nitric oxid is read with the tube in such a position that the level of the solution within and without the tube coincides. The caustic solution in the jar should be kept at room temperature’’. 506 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 Hoagland suggested a convenient device for cooling the soda solution in the trough during the determination which greatly facilitates the operation. It consists of fitting a single coil of tin tubing into the trough and passing a current of cold water through it during the determination. It would be advisable to add the following suggestion of Hoagland as an explanatory footnote on the manipulation of the method: After all of the air has apparently been driven out of the apparatus, boil a short time longer after the delivery tube has been placed under the eudiometer to make certain that no air remains. Gradually introduce a measured portion of standard nitrate solution, rinse the funnel tube with 10% hydrochloric acid, and boil until all of the nitric oxid has been driven over. After the gas tube has been removed, quickly invert another tube over the delivery tube and boil a short time longer to make sure that all of the nitric oxid has been driven over. Run another portion of the standard solution into the apparatus, and repeat the determination. Then run the samples in the same way, in each case making certain that all of the nitric oxid has been driven over. After running 6-8 determinations, not counting the standards, finally run another standard. The three standards should check within 0.5 cc. on about 35 cc. RECOMMENDATIONS. It is reeommended— (1) That further work be done on this method, using beef extract, meat and other meat products. (2) That the following 1916 recommendation be studied during the coming year: That the referee for next year attempt to determine the relative amounts of some of the dissociation products in water-soluble and water-insoluble meat proteins. (3) That the title of the method be changed from “Nitrates” to “Nitrates and Nitrites (calculated as sodium nitrate)”’. No report on meat extracts was made by the associate referee for the year ending November, 1918. REPORT ON MEAT EXTRACTS. By GC. R. Moutrton (Agricultural Experiment Station, Columbia, Mo.), Associate Referee. Nothing definite has been accomplished during 1919. It is reeommended— (1) That an attempt be made to determine the relative amounts of some of the dissociation products in water-soluble and water-insoluble meat proteins. This probably can best be accomplished by studying certain groups of amino acids, or other protein derivatives, in meat and meat extracts, in collaboration with other referees to be appointed by the association. 1 Associate referee for the year ending November, 1919. 1921] MOULTON: REPORT ON MEAT EXTRACTS 507 (2) That the work on the separation of some of the amino acids derived from meat proteins be continued. (3) That the associate referee be not bound to a single method, but be left to choose as circumstances dictate and the collaborators accept. REPORT ON EGGS AND EGG PRODUCTS? By C. E. Marsu (State Department of Health, Boston, Mass.), Referee. The work of the last two years consisted of the following: (1) Testing methods for the determination of decomposition in eggs. This included a comparison of the Folin? and the Hendrickson and Swan method for the determination of ammoniacal nitrogen*, and the comparison of the United States Department of Agriculture method for the determination of dextrose with that of Klein. (2) Analyses showing the composition of both fresh and decomposed eggs. (3) Methods for the detection of decomposition in dried eggs. (4) Methods for the determination of heavy metals in dried eggs. Later, it was suggested by R. W. Hilts (U. S. Food and Drug Inspec- tion District, U. S. Appraiser’s Stores, San Francisco, Calif.) that work be done on Juckenack’s method on lecithin-phosphoric acid‘ with a view to reaching a suitable official method. This suggestion was adopted, and the following methods sent out to the collaborators: FOLIN METHOD FOR AMMONIA’. Weigh about 20 grams of the well-mixed sample into a cylinder, add 5 cc. of satu- rated sodium carbonate, 2 cc. of a saturated solution of potassium oxalate, and some mineral oil to prevent frothing. Close the cylinder with a stopper containing two tubes, one of which reaches to the bottom of the cylinder, the other being of the distillation bulb and trap type to prevent any liquid passing over. The lower end of the second tube should pass into a 100 cc. flask containing about 50 cc. of water and 2 cc. of N/10 acid. If the outlet tube from the cylinder is slightly larger than the inlet, frothing will be reduced. Now blow a current of air (freed from ammonia by being passed through a sulphuric acid bottle) through the eggs, any ammonia carried over being absorbed by the acid. About 2 hours is usually required for this part of the process, but the exact time should be determined by experimentation in each laboratory. The cylinders found most convenient by the Massachusetts State Department of Health are 11} inches tall and 2 inch in diameter, inside measure. After the complete distillation of the ammonia, dilute 5 cc. of Nessler’s solution with 25 cc. of water. Add this in three portions to the distillate, and dilute with water to 100 ce. Compare the colored solution, in a Duboscq colorimeter, with that produced 1 Presented by H. C. Lythgoe. 2 J. Biol. Chem. 1912, 11: 493. 3 J. Ind. Eng. Chem., 1918, 10: 614. 4 Z. Nahr. Genussm., 1900, 3: 13. 8 J. Biol. Chem., 1912, 11: 493. 508 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 from a known amount of ammonium sulphate (usually 1 mg. per 100 cc.) treated in the same way with the Nessler reagent, and calculated as mg. per 100 grams. The standard ammonium sulphate is conveniently made of such strength that 5 cc. con- tain 1 mg. of nitrogen. Preparation of the standard—As ordinary C. P. ammonium chlorid contains pyridin and other bodies which interfere with the reaction of the Nessler solution, it is necessary to treat some of it with sodium carbonate in an apparatus similar to that described on page 507, and blow into C.P. dilute sulphuric acid until it is neutralized. Precipitate the ammonium sulphate with an equal volume of alcohol, filter, and dry. To obtain a standard solution of which 5 cc. contains 0.001 gram nitrogen, 0.471 of the purified product should be dissolved in sufficient water to make 500 cc. of solution. When a blank is distilled with this standard, at least 95% of the ammonia should be recovered; with ordinary C. P. ammonium chlorid only about 80% can be recovered. HENDRICKSON AND SWAN METHOD FOR THE DETERMINATION OF AMMONIACAL NITROGEN. Weigh 25 grams of the well-mixed sample into a tared dish, and pour into the aera- tion cylinder, transferring the egg adhering to the sides of the weighing vessel with the aid of four successive 25 cc. portions of ammonia-free water. Add 75 cc. of alcohol, mix, and let stand for 15 minutes. Then add 10 grams of sodium fluorid, 2 cc. of 50% potassium carbonate, and 1 cc. of kerosene. Connect the apparatus, and aerate strongly until no more ammonia comes over, then titrate at once with N sodium hydroxid. The apparatus used is essentiaily that of Folin, except that an aeration cylinder 50 mm. in diameter and 350 mm. high is used. Ordinary glass tubing sealed at the bottom and with small holes punctured according to the method of Folin and Farmer? is used in place of the special ammonia absorption tubes. It is recommended that a blank containing 1 mg. of nitrogen be run at the same time as the sample. UNITED STATES DEPARTMENT OF AGRICULTURE METHOD FOR DEXTROSE IN EGGS’. After thoroughly mixing the sample, weigh 25 grams into a 100 cc. lipped beaker. Wash the sample into a 200 cc. graduated flask, using 70 cc. of distilled water. (Add about 40 cc. first, and mix the sample with the water by stirring with a rubber-tipped glass rod. After the contents of the beaker have been poured into a graduated flask, use a 20 ce. and finally a 10 cc. portion of distilled water to thoroughly wash the beaker.) Then add 2 cc. of 5% acetic acid to the sample if it be egg white, or 1 cc. of the acid if the sample is mixed egg or egg yolk; mix thoroughly by shaking the flask, and place the flask in a water bath at 100°C. Egg should coagulate in 10 minutes. (There is danger of foaming during the first 5 minutes of heating.) After the egg material has been coagulated, place the flask in cold water until the contents are of room tempera- ture. Then make up to the mark with alumina cream that has been washed several times to take out the dissolved salts. Shake the sample vigorously for 1 minute, allow it to stand about 5 minutes, and then shake for 1 minute. The egg material should then filter readily, especially if folded filters are used. The filtrate is clear and nearly colorless, and the reducing sugars determined in an aliquot should be calculated as dextrose. Fresh egg white yields about 0.44% of dextrose; Fresh egg yolk yields about 0.22% of dextrose; and Fresh mixed egg yields about 0.34% of dextrose. 1 J. Ind. Eng. Chem., 1918, 10: 614. 2 J. Biol. Chem., 1912, 11: 493. 3 Personal communication from U. S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, Boston, Mass. So ee 1921] MARSH: REPORT ON EGG PRODUCTS 509 The results were obtained from composite samples, and variations of as much as 0.03 per cent seldom occur. As the egg material deteriorates, the dextrose content decreases. If the liquid egg has an excess of white or of yolk, the dextrose content can readily be calculated if a moisture or a fat determination is made. KLEIN’S MODIFICATION OF THE BENEDICT AND LEWIS METHOD FOR THE DETERMINA- TION OF DEXTROSE IN EGGS". ESTIMATION OF REDUCING SUBSTANCES IN FROZEN AND FRESH EGGS. Weigh out 5 grams of eggs and wash into a 100 cc. sugar flask with about 25 cc. of water and fill up to the mark with a saturated aqueous picric acid solution. Shake the mixture thoroughly and allow it to stand for about 10 minutes. Filter the clear, yellow, supernatant liquid through a dry, double-folded filter paper. Introduce 10 ce. of the filtrate into a 50 cc. volumetric flask to which 3 cc. of saturated picric acid, 2 cc. of sodium carbonate solution (10 grams of anhydrous sodium carbonate to 100 cc. of water), and a few glass beads are added. Heat the flask on a sand bath until the solu- tion is evaporated nearly to dryness. Care must be taken not to char the organic matter. A color will develop, varying in shade from yellow to dark red, depending on the amount of reducing matter present. Wash the neck and the sides of the flask with a few cc. of hot water, and boil the solution for about 3 minutes. Add warm water to dissolve the evaporated mass. Cool the flask to room temperature, and make up the contents to volume. If the solution is turbid, filter it through a cotton plug, rejecting the first few cc. of the filtrate. Introduce the clear liquid into a Duboscq colorimeter chamber, and compare with a standard. The standards are made up as follows: Prepare a solution having a color intensity equivalent to 0.004% of dextrose by dissolving 1 gram of C. P. dextrose in 500 cc. of water, diluting 20 cc. of this solution with 140 cc. of aqueous saturated picric acid solution, and making up to 200 cc. with water. Treat 10 cc. of this solution, containing 0.002 gram of dextrose, in the same way as described above. This standard is satisfactory for whites and whole eggs. For yolks and decomposed eggs, a weaker standard should be used. If the original sample contains 0.2%, or less, of reducing matter as dextrose, it is advisable to compare it with a standard equivalent to 0.2% of dextrose, or, if it contains less than 0.1% of reducing matter as dextrose, with a standard of 0.1% of dextrose. It is advisable in all cases to have about the same concentration of free picric acid in the standards as is present in the unknown solutions. Calculations—Dilute 5 grams of the sample to 100 cc.; finally dilute 10 cc. to 50 cc. The sugar standard with which it is compared contains 0.002 gram of dextrose in the Per a emt as dextrose in sampl: Eine aa ee x e = e = Reading of unknown Later in the year a sample of dried egg was sent to each collaborator for the determination of lecithin-phosphoric acid, as described by Leach?. Although few of the collaborators sent in any report, some gave very complete ones. The following suggestions and methods are taken from them: } Personal communication from David Klein, Division of Foods and Dairies, State Department of Agri- culture, Chicago, Ill. 2A.E. Leach. Food Inspection and Analysis. 3rd ed., 1913, 349. 510 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 G. C. Swan (Food Research Laboratory, 1833 Chestnut Street, Philadelphia, Pa.) states: The determinations found most valuable for the detection of decomposition in eggs are total solids, ether extract, acidity of ether extract, ammoniacal nitrogen, reducing sugar, indol and skatol, bacteria, and, of course, physical appearance. The ammoniacal nitrogen determination is of most value, for it best indicates incipient decomposition, which is perhaps the condition most commonly met. The total solids and ether extract must be known in order to properly interpret the results for ammoniacal nitrogen and reducing sugar. Practically all the ammoniacal nitrogen is found in the yolk of the egg, while the white contains over twice as much reducing sugar as the yolk. This is shown in Table 1. Total solids —Weigh out 3-5 grams of a well-mixed sample into a tared dish (lead bottle caps, which can be rolled up in fat-free filter paper for the ether extract, are useful), and dry in a vacuum oven at 55°C. to prevent coagulation. The vacuum should be 25 inches or over. It is recommended that weighings be made at the end of 24 hours’ drying, and thereafter at intervals of about 45 minutes. There is an appreci- able gain in weight after the minimum has been reached. Ether extract.—Extract the dry residue from the total solids determination in a Knorr extraction apparatus with absolute ether. Extraction for 3 hours is sufficient if the apparatus is working rapidly. (The rolling up of the lead dishes containing the sample in filter papers makes it unnecessary to use an asbestos plug in the bottom of the ex- traction tube.) Distil off the ether, and dry in vacuo for 1 hour at 55°C., cool in a desiccator, and weigh. Acidity of ether extract-—Dissolve the ether extract in 50 cc. of neutral benzol to which 2 drops of phenolphthalein have been added, and titrate with N/20 sodium ethylate to first pink color. Express the results as the number of cc. of sodium ethylate required to neutralize 1 gram of ether extract. Indol and skatol.—Place 200 cc. of liquid egg, 40 cc. of 5% acetic acid, and 500 ce. of water in a liter flask, and coagulate the protein in a steam bath or Arnold sterilizer. Then filter the material through a folded filter, and distil the filtrate with steam. Extract the indol in the distillate with a small amount of ether in a separatory funnel, add 1-2 ce. of water, and volatilize the ether before a fan until only a slight odor remains. Test the watery solution remaining according to the directions for the vanillin test given by V. E. Nelson!. Make the bacterial examination according to the directions given by the Bureau of Chemistry?. The following figures in Table 1 are taken from work done by Swan and are repre- sentative. 1 J. Biol. Chem., 1916, 24: 528. 2U.S. Dept. Agr. Bull. 51: (1914). 1921] MARSH: REPORT ON EGG PRODUCTS 511 Taste 1. Determination of decomposition in eggs. (Analyst, G. C. Swan.) DETERMINATION ] eam eee at Total Ether | Acidity | Ammoniacal| Reducing solids extract | beater nitrogen sugar mg. per 100 } per cent per cent ec.* grams per cent MAIER arts 2 Ja. Bis OOOLSE Pecan. 0.00048*) 0.00047 | .... = | one 0:00200") 222 O.001245 | oe O:267)|S.- 10-370) 0.00180 | 0.00185 | 0.00116 | 0.00120 | 0.262 | 0.264 | 0.384 | 0.380 OLO0D TO nshs-siees (OHO APA Oe Eee O23 4 Nesey 02248) eer 0.00173 | 0.00176 | 0.00106 | 0.00109 | 0.231 | 0.232 | 0.240 | 0.244 O002315 | eae 01002821) 2a ae: O2162))| 7.2. 31/0:200)| ae 0.00213 | 0.00222 | 0.00264 | 0.00273 | 0.157 | 0.160 | 0.208 | 0.204 O00 264 cae 0.0039 O20) ae OLE 70) |e 0.00241 | 0.00253 | 0.0022 | ...... 0.10 | 0.15 | 0.136 | 0.153 Q!00269) Ihakd Seen | Mees Sal) By See O05) a 10.076: |e 0.00242 | 0.00256 0.07 | 0.06 | 0.072 | 0.074 O\0034. Wile. cae O0037) i) vate ee OLOZS8 i) cece 010.088) ere 0.0031 0.0032 | 0.0036 | 0.00365 | 0.057 | 0.067 | 0.096 | 0.092 * Aerated 2 hours while the following determinations were allowed to run for 4—6 hours. + Distilled water used for rinsing, causing high results. Of the two methods for ammoniacal nitrogen, the Hendrickson and Swan method was much more satisfactory than the Folin colorimetric method. The range of variation is so narrow that it would seem to be very difficult to fix any definite dividing line for the percentage of nitrogen in edible eggs and those not fit for food. The United States Department of Agriculture method for dextrose seems to give more uniform results and is easier to control than Klein’s colorimetric method. The range of variation in the percentages of dextrose is wider than that of nitrogen, and would seem to be a more reliable indication of the age of the eggs. 1921] MARSH: REPORT ON EGG PRODUCTS 513 FOLIN METHOD FOR AMMONIACAL NITROGEN IN EGGS. TABLE 3. Effect of varying the aeration period, other conditions being constant. AMMONTACAL NITROGEN CONTENT OF EGGS AERATED QUALITY OF EGGS 2 hours 4 hours 6 hours | 8 hours | ] mg. per 100 grams | mg. per 100 grams | mg. per 100 grams | mg. per 100 grams Rota ect 0.00168 | 0.00162 | 0.00168 0.00174 0.00156 0.00168 0.00168 0.00180 | Strictly fresh....... 0.00018 0.00028 | 0.00034 0.00038 0.00020 0.00030 | 0.00032 0.00040 As a result of the extremely low results obtained on fresh eggs by the Folin method, the series of determinations shown in Table 3 were made. In the fresh eggs, the increase in the percentage of nitrogen is very pro- nounced, depending on the period of aeration, while in stale eggs, the period of aeration has little effect after the first 2 hours. R. W. Hilts gives the following suggestions regarding Juckenack’s method: Mix 30 grams of the finely ground sample with a teaspoonful of asbestos fiber rubbed through a screen. Pack this mass in a paper extraction capsule, and place in a Soxhlet extractor. Further manipulation is the same as that described by Juckenack, except that the volumetric method of determining phosphoric acid is generally employed. Raymond Hertwig (U. S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, San Francisco, Calif.) sends the following report on the determination of lecithin-phosphoric acid in a sample of dried egg: Grind the sample in a mortar to as fine a powder as possible. Extract the lecithin- phosphoric acid with hot absolute alcohol by two slightly different methods: (1) Juckenack method.—Place 3 grams of the sample in a Soxhlet extractor in a paper capsule, mix with some ignited asbestos, and extract for 10 hours. Add 10 ce. of 4% alcoholic potash to the extract, and nearly evaporate the alcohol. Wash the residue into a platinum dish, evaporate, dry, and burn in a muffle at below redness for a few minutes, until all the fat is burned off. Extract the mass with hot, dilute nitric acid, and filter the solution. Ash the washed filter paper in the platinum dish to a white ash, treat this with dilute nitric acid, and filter into the first filtrate. Deter- mine the phosphoric acid in the complete filtrate by the volumetric method’. (2) Heat 3 grams of the sample in an Erlenmeyer flask on the steam bath with 125 cc. of absolute alcohol for 2 hours. Place a funnel in the mouth of the flask to condense the alcohol vapors. Filter the solution, and wash the filter paper with a little hot abso- lute alcohol. Subsequently treat the filtrate as in Method 1. Method 1 gave 1.323-1.328 per cent lecithin-phosphoric acid as P,0;, while Method 2 gave 1.312 per cent. Method 2 gave practically the same results as Method 1. If it were po sible to use Method 2 on dry products, it would have the advantages of shorter time of extraction, inexpensive apparatus and simplicity. 1 Assoc. Official Agr. Chemists, Methods, 1916, 3. 514 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 H. C. Lythgoe! (State Department of Health, Boston, Mass.) states that strictly fresh eggs contain less than 1 mg. of ammonia per 100 grams of egg, but reasonably fresh eggs may contain as high as 2 mg. of ammonia per 100 grams of egg. When the ammonia content exceeds 4 mg. per 100 grams, the egg passes into the class of decomposed eggs. He finds that as a rule in December, January and February cold storage eggs compare favorably in ammonia content with the so-called ‘‘fresh’’, or “fresh western’ eggs as sold in the stores at a price considerably above that asked for cold storage eggs. As practically all of the ammoniacal nitrogen and acidity occur in the yolks, while most of the reducing sugars occur in the whites, it is necessary to know the amount of fat in broken-out eggs containing varying amounts of added yolk, in order to properly interpret the results. Table 4 gives the highest limits of ammonia and acidity allowable in broken-out eggs with varying amounts of added yolk. The acidity is calculated as cc. of N/10 acid for 100 grams of egg and the ammonia as mg. for 100 grams of egg. TABLE 4. Highest limits of ammonia and acidity allowable in broken-oul eggs. (Analyst, H. C. Lythgoe.) FAT AMMONIA ACID per cent mg. per 100 grams cc. per 100 grams 10 4.0 25.0 il 4.4 27.5 12 4.8 30.0 13 5.2 32.5 14 5.6 35.0 15 6.0 37.5 16 6.4 40.0 17 6.8 42.5 18 1.2 45.0 19 7.6 47.5 20 8.0 50.0 21 8.4 52.5 22 8.8 55.0 23 9.2 57.5 24 9.6 60.0 25 10.0 62.5 26 10.4 65.0 27 10.8 67.5 28 11.2 70.0 29 11.6 72.5 30 12.0 75.0 31 12.4 77.5 32 12.8 80.0 33 13.2 82.5 1 Mass. State Dept. Health, Monthly Bull., 1918, 5: 328. enneettlladtiee aed 1921] MARSH: REPORT ON EGG PRODUCTS 515 In the Massachusetts Department of Health laboratory the compari- sons shown in Table 5 were made. TABLE 5. Comparative results on different quality of eggs. AMMONIA DEXTROSE QUALITY OF EGGS SOLIDS FAT U.S. De- Folin partment of Klein method Agriculture method method mg. per 100 irr ater glass p per cent per cent grams per cent per cent RVCATSoes ve ac ate aticr es ate Boe 6.08 Atak RVCRES nia tre sie steno ek aaa Bae 4.95 viene ARVOATS ah arcicr. wiyete a isveabore:s are std 7.24 Perr Wiatervlassa onsen Seger ee 7.41 0.45 Whaterp lass gic vonec a: meet Aa 7.41 0.53 Cold storage 2 years and considerably dried... ... 40.84 10. Peet 0.40 0.584 Wraterplass niobate = 26.70 14. 2.54 0.355 0.336 Gommercialy ois 472 «sa osers 28.60 16. 3.47 See 0.338 Commercial) snes tee. 27.62 14. 3.29 0.415 | The referee tried both methods for ammonia, and relies on the Folin method. The principal disadvantage with the Hendrickson and Swan method is the great difficulty of cleaning the glassware. The Klein method for dextrose was found to be quicker than the United States Department of Agriculture method, and better where a large number of determinations was to be made at once. Several of the dextrose determinations by the United States Department of Agriculture method were unsatisfactory, because of faulty clarifying and filtering, but no trouble was found in the same sample using the Klein method. No work was done by any one in the determination of heavy metals in dried eggs, although A. S. Thatcher (Loose-Wiles Biscuit Co., New York, N. Y.) suggested that the method of the Bureau of Animal Indus- try for gelatin might be useful. The general opinion about tests for the determination of decomposi- tion in dried eggs was that there were no satisfactory chemical tests. Some work done by the referee seemed to indicate that the acidity might be of some value as an indication of decomposition. RECOMMENDATIONS. It is reeommended— (1) That the Folin method for the determination of ammoniacal nitrogen in eggs be adopted as a tentative method. 516 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 (2) That further comparisons of Klein’s method and that of the United States Department of Agriculture for the determination of dex- trose be made with a view to adopting one of them as official. (3) That further work be done on the methods as given for the deter- mination of lecithin-phosphoric acid in dried eggs and alimentary pastes. (4) That work be done on the determination of heavy metals in egg products. (5) That work be done on methods for the detection of decomposi- tion in dried eggs. DISCUSSION OF REPORT OF REFEREE ON EGG PRODUCTS. By H. W. Reprietp (U. S. Food and Drug Inspection Station, U. S. Appraiser’s Stores, New York, N. Y.). Many of the conclusions and criticisms to be offered are based upon the results of an exhaustive investigation, conducted by the Bureau of Chemistry', on the correlation existing between analytical data and the quality of frozen egg products. One of the objects of this investi- gation was to perfect analytical methods by means of which a correct judgment might be reached as to the original condition of preserved foods, and it is recommended that the methods used for this work be designated the United States Department of Agriculture methods. The method employed for the determination of ammonia nitrogen differs somewhat from the Folin method for ammonia, as described by the referee, page 507, resembling rather the method ascribed by the referee to Hendrickson and Swan, page 508. In practically every instance when four analysts determined the ammonia nitrogen in the same sample, results which did not vary from one another by more than a few hundredths of a milligram per 100 grams of sample were obtained, which is one of the crucial tests of a method. In all of the 83 samples of fresh and frozen eggs examined the ammonia nitrogen was determined by the titration method’, the Nesslerization method’, and the phosphotungstic acid method‘. The following con- clusions were unanimously reached: (1) The titration method for ammonia nitrogen? is accurate, reliable, and much to be preferred to any other where legal action may be involved. (2) The Nesslerization method for ammonia nitrogen*, while more 1U_S. Dept. Agr. Bull. 846: (1920). 2 [bid., 90. 3 Tbid., 92. * Ibid., 93 1921] REDFIELD: REPORT ON EGG PRODUCTS 517 rapid, is not so accurate as the titration method. If it is employed for samples where legal action may be involved, it should be run in tripli- cate, and the average of the three determinations used. (3) The phosphotungstic acid method! is good for rapid and approxi- mately accurate work, but should not be used for samples where legal action may be involved. The dextrose method described by the referee as the United States Department of Agriculture method, page 508, is almost like that used throughout the investigation with two exceptions. In the first place, the referee’s method specifies the use of 1 cc. of acetic acid in the case of mixed egg. If by this he means yolky mixtures, he has neglected to state the quantity to be used for whole egg. Two cc. should be used for whole egg. Secondly, he says that the egg should coagulate in 10 min- utes. Proper coagulation requires 15 minutes. Necessary details in the method for ether extract, not mentioned in Swan’s report, page 510, include the preparation of the material for extraction and the amount of vacuum in drying. The method for indol and skatol differs from that of Swan in that the egg material is diluted before adding the acetic acid, using 40 cc. of acetic acid for white or whole egg, and 20 cc. for yolk, is taken up with water after the evaporation of the ether, and is then filtered before testing for indol or skatol. The vanillin test is a modification of the one given by V. E. Nelson?. It was considered essential to confirm for indol with a modification of the para-dimethylaminobenzaldehyde test and for skatol with an adaptation of the dimethylaniline test. The directions given for the bacteriological examination® are not sufficiently exhaustive for egg products. Swan’s statement, page 511, that ammoniacal nitrogen tests are of little value for detecting the fact that decomposed eggs have been used in making dried egg products is open to question. Experiments made by the Illinois Division of Foods and Dairies indicate very strongly that even when dried in a vacuum of 29.6 inches on a commercial scale, practically none of the ammonia was removed from the egg material. It would seem that if ammonia could be removed by any commercial process it would be by this vacuum process. Swan’s contention, page 511, that the matter of detecting the use of decomposed eggs in making desiccated egg products should be vigor- ously attacked is well taken. Such an attack, however, can not be made in this country. It must be made in China. Conclusions drawn from samples prepared in the laboratory on a small scale would be of little 1U.S. Dept. Agr. Bull. eae 2920); 93. 2 J. Biol. Chem., 1916, 24: 3U.S. Dept. Agr. Bull. 51: 4914), 3. 518 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 value. The material to be studied must be handled on a commercial basis, and China is the only place now where that is being done. The ammonia nitrogen figures, page 512, given by A. R. Todd (State Food and Drug Department, Lansing, Mich.), using both the Hendrick- son and Swan method and the Folin method, for strictly fresh, store fresh, frozen 4 months, stale, small blood rings, green whites, moldy, and blood-rot eggs are all very much too low, probably because he did not use enough air pressure in aeration. The use of a cylinder 3 inch in diameter for holding the material to be aerated, as recommended by the referee, page 507, makes it impossible to apply enough air pressure, as in a cylinder of that size all of the material would be promptly ele- vated out from the top if sufficient air pressure to do any good in a reasonable length of time was turned on. The cylinder should be much larger. the air pump should provide at least 10 pounds pressure per square inch, and there should be an equalizing tank between pump and cylinders to eliminate the effect of the pulsations of the pump. The results secured by Todd, page 512, for what he calls dextrose (more properly “reducing substances calculated as dextrose’) by the alleged United States Department of Agriculture method seem to be correct. All of the substances in eggs capable of reducing Fehiing’s solution are not dextrose, as is well illustrated by the fact that if the reducing substances in a sample of whole egg, yolk, or white are determined, the material frozen and held for a year and the reducing substances again determined, there will be more at the end than at the start. Is that due to the formation of dextrose in the frozen material? Hardly. What probably happens is the breaking down of some of the ovomucoid, which is a glycoprotein and on hydrolysis yields a reducing substance, presumably chondroitin-sulphuric acid. This may break down into glucosamin or some similar substance. Todd's results, page 512, for dextrose by the Klein method are too high, probably because of charring on evaporation. His results for Babcock fat, page 512, are much higher than those obtained by any other analyst using the admittedly more accurate extraction method. Whether Todd’s general deduction, page 512, that the dextrose content is a more reliable indication of the age of eggs than ammonia nitrogen is true or not depends entirely upon the bacterial flora of the eggs and whether the predominating changes during aging are fermentative, pro- teolytic, or lipolytic. Since they may be any of these, the quality of eggs can not be judged by any one chemical determination. This is supported by Swan’s statement, page 510, that the valuable methods for the detection of decomposition in eggs are total solids, ether extract, acidity of ether extract, ammoniacal nitrogen, reducing sugar, indol and 1921] KEDFIELD: REPORT ON EGG PRODUCTS 519 skatol, bacteria, and, of course, physical appearance. All of Todd’s figures, page 512, for ammonia nitrogen, as determined by the Folin method, using different periods of aeration, in rots and strictly fresh eggs, are so low as to prove conclusively that the method pre- scribed by the referee, as operated by Todd, is absolutely unreliable. H. C. Lythgoe’s (State Department of Health, Boston, Mass.) state- ment, page 514, that, ‘‘When the ammonia content exceeds 4 mg. per 100 grams, the egg passes into the class of decomposed eggs’’, unquestion- ably should be amended to read, “has long since passed into the class of decomposed eggs’’. His statement that it is necessary to know the amount of fat in broken- out eggs containing varying amounts of added yolk, in order to properly interpret ammonia nitrogen results, is true. The simplest way to do this is to plot the ammonia nitrogen results against the ether extract and calculate the formula value. Obviously this is unnecessary in the case of acidity of fat if the acidity is calculated to a per gram of fat basis. The allowable limits set by Lythgoe, page 514, for ammonia nitrogen and acidity of fat in broken-out eggs with varying amounts of added yolk are entirely too high. His ammonia nitrogen figures give a clean bill of health to more than half of the samples known to be inedible when made up for the investigation conducted by the Bureau of Chem- istry in August, when eggs are admittedly at their worst. Moreover, only two of the samples known to be inedible when made up would fall above Lythgoe’s line of highest allowable results for acidity of fat; all the rest would pass. The only eggs excluded by Lythgoe’s highest allowable limits for ammonia nitrogen and acidity of fat would be the most stinking of decomposed eggs; the moderately stinking eggs would not be excluded. Some of the results reported from the Massachusetts State Depart- ment of Health laboratory, page 515, are curious. For example, 10 per cent of fat in eggs containing 40.84 per cent of solids, and 14, 16, and 14 per cent of fat, respectively, in eggs with 26.70, 28.60, and 27.62 per cent of solids seem rather unreasonable. In that laboratory, the Folin nitrogen method, as manipulated, apparently gave reasonable results, but the same can not be said of the Klein dextrose method. The statement of the referee, page 515, that his results show the Klein method to be better than the United States Department of Agriculture method seems unwarranted. The referee’s recommendation that the Folin method as described in the report be adopted as a tentative method should not be accepted by the association, because it evidently does not give concordant results in 520 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMisTS [Vol. IV, No. 4 the hands of different workers, as proved by the result of the referee and Todd. The referee’s recommendation that further comparison of the Klein and United States Department of Agriculture methods for dextrose be made with a view to adopting one of them as official, should not be accepted by the association unless the alleged United States Department of Agriculture method is first made correct. REPORT ON GELATIN. By C. R. Smirx (Bureau of Chemistry, Washington, D. C.), Referee. The work on gelatin for 1918 and 1919 involved a study of its polari- scopic constants and a method for the determination of sulphites. The usefulness of the polariscopic study of gelatin is indicated in the study of jelly strength and certain other applications'. The estimation of sulphite by the present association method? is troublesome; the sug- gested method offers rapid results but needs to be tested for accuracy. Since the proportion of sulphites decreases with time, results should be obtained by the collaborator comparing the proposed diffusion method and the distillation method at the same time. In determining the optical rotation of gelatin in equilibrium at 15°C., it is very important to control the temperature carefuliy for accurate results. In all cases, improvised constant temperature baths were used. In view of this, the results were fairly satisfactory. POLARISCOPIC CONSTANTS OF GELATIN. Prepare concentrations of 2 and 3 grams per 100 cc. of both samples, lettered S. C. S. and T. D. T., by soaking in 40-50 cc. of cold water, heating to about 50°C. for 15 minutes and making to volume at 35°C. Polarize at 35°C. in 200 mm. tubes. Fill 100 mm. tubes of each concentration in duplicate to obtain the equilibrium rotation at 15°C. To avoid strains in the jellies, cool the solutions quickly to 10-15°C. and pour into cold dry tubes before jelly has been formed. Place the tubes in a con- stant temperature bath at 15°C. and leave overnight. Polarize the next day at 9 a. m., 12 m. and 4 p. m. Tabulate the results after doubling the rotations at 15°C. to place all readings on 200 mm. tube basis and using Ventszke degrees as in saccharimetry as shown in Table 1. In place of a constant temperature bath, place the tubes in a part of the ice chest registering between 12 and 16°C. overnight. Carefully control the temperature at 15°C.+ 0.4°C. the next day by immersion in a large volume of water maintained at 15°C. or carefully control in a dry container which is a poor conductor of heat an placed in a part of the ice chest which is near the correct temperature. 1 J. Ind. Eng. Chem., 1920, 12: 878. 2 Assoc. Official Agr. Chemists, Methods, 1916, 150. 1921] SMITH: REPORT ON GELATIN 521 SULPHUR DIOXID—DIFFUSION METHOD. Take 5 grams of powdered gelatin sample; add 100-150 cc. of ice water < ontaining 3 ec. of 10% hydrochloric acid (1 to 3) and 10 grams of sodium chlorid. Gently mix and allow to stand in ice water for 2 minutes. Add starch paste of :ood quality and titrate with N/100 iodin until a blue color appears. Replace in the ice bath for 1 min- ute, remove, and titrate carefully until the color reappears. Repeat these operations until the color remains after standing for 1 minute with gentle agitation. Report the number of cc. consumed and calculate the sulphur dioxid as mg. per kilo. 1 ec. N/100 I = 0.00032 gram of SO:. If possible, check the diffusion method with the distillation method', using a stream of inert gas and recovering the sulphur dioxid as barium sulphate. TABLE 1. Polarizations of Sample S. C. S. | POLARIZATION AT 15°C. ROTATION AT FO POLARIZATION 15 AT 35°C. ] ROTATION AT aren 9 A.M. 12 M. 4P.M. 35°C. r l | | | | | 2 grams | 3 grams |2 grams3 grams2 grams3 grams2 grams3 grams 2-gram) 3-gram } | f ratio | ratio + ES eS ee | | W. D. Richard-|—13.7 |—20.2 | —29.7) —43.8, —29.5 —44.9 —29.1) —44.7| 2.148 | 2.127 Son Swit Gol, ||arias |) cus-ic [Whereas | ABA S| SAR Ah. || — 43:6) Pee Chicago, Ill. | | | | T. R. Tennant, |—13.55 —20.5 | —28.9 —43.4 —29.0 —43.5 —29.0 —43.4) 2.14 2.12 United Chemi- | | cal and Organic | | | Products Co., | Hammond, | | Ind. | | | | | R. Hertwig, U.|—15.2 |—20.2 —28.0|—40.4 —29.6 —44.8 —28.8 —46.0/ 1.89 | 2.15 S. Food and | | | —31.4 —43.6| 2.06 | 2.27 Drug _Inspec- | tion Station, U. | | Appraiser’s | Stores, San Francisco, Calif. E. H. Berry, U. |—13.6 |~20.3 |—31.0 —45.0 .... | .... |—25.0|—40.0) 1.83 | .... S. Food and | | | Drug _Inspec- | tion Station, | Transportation } Building, Chi- cago, Ill. L. A. Salinger, | | U.S. Food and | | | Drug __Inspec- tion Station, U. | | | Ss. Custom H House, Savan- nah, Ga.: | | October 4, | ONO cre | —18.85) —20.5 |—27.7, —42.3) —28.0| — 40.9 —28.7) —40.1) 2.08 | 1.95 October 20, | } | it eee coe eee — 20.75) —29.7 —45.0 rete —44,2) —29.6 —43.1| 2.19 | 2.08 | 1 Assoc. Official Agr. Chemists, Methods, 1916, 150. } 522 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 TABLE 2. Polarizations of Sample T. D. T. POLARIZATION AT 15°C. ROTATION AT | POLARIZATION — 15°C. — AT 35°C. | ROTATION AT 9 A.M. 12M. 4 P.M. 35°C; ANALYST | F 5 2 3 2 2-gram| 3-gram grams| 3 grams 2 grams|3 grams)? grams io SS On | Se W. D. Richard- —13.8}—21.1 | —25.6) —39.2) —25.2| —38.7/ —25.8] —39.5 1.847 | 1.856 son .... | .---- | —20.0| —40.0) —25.2| —38.6; —26.6] —39.0 .... | .... T. R. Tennant.. —13.6]—20.5 | —25.8) —39.0) — 26.0} —39.0 —26.0) —39.0 1.89 | 1.90 R. Hertwig..... —13.8|—20.2 —26.0) —38.8} —26.1) —39.3 —26.4) —39.9| 1.913 | 1.975 wee tece [cece | sees | ae---|—26.3]—39'3) 15906) 12045 E. H. Berry. . .. —13.7|/—20.2 —27.0)—40.0) .... | .... |—24.0) —36.0) 1.71 1. A Salinger: October 4, 1919*, —14.0| 20.65 —26.0| —41.3| —26.2| —39.7, —25.7| —37.4| 1.83 | 1.79 October 20, 1919 —14.1|—21.0 —26.5) —39.0| —27.1| —40.6 —27.2| —39.7| 1.93 | 1.93 | * Average. TABLE 3. Determination of sulphur diorid in Sample S. C. S. by the diffusion method. ! ANALYST N /100 ropin SULPHUR DIOXID cc. mg. per kilo Weabuinichardson= o-oo. see cee oer Secrest 2.54 152.5 2.68 171.6 Be EEBernys: & 555 .scccs5.csctos ve cis!opeestengis srk om ore nerve 2.9 185.8 Re Hertwig? sass eases cde sacle Sa eee cee anc 3.5 220.0 L. A. Salinger (October 20, 1919)..............-.-- 1D 76.8 Comparison can not properly be made between the results of different collaborators made at different times. The result of Salinger was obtained last and shows that over half of the sulphur dioxid had disappeared. Richardson reported the sulphur dioxid on a good grade of glue as 4440, 4141, 4347 and 4231 mg. per kilo as compared with 3212, 3212, 3166 and 3102 mg. by the diffusion method. COMMENTS. Hertwig reports that the polariscope he used for the 35°C. readings did not read farther than—20°V. He estimated the 35°C. readings given for the 3-gram concentrations as probable values. Salinger reports that warm, humid weather made readings difficult. 1921] SMITH: REPORT ON FATS AND OILS 523 Richardson had no suitable cooler to maintain the required tempera- ture. Berry reports irregularity in ice chest temperature during the night and difficulty in making readings at the lower temperature. REPORT ON EDIBLE FATS AND OILS. By R. H. Kerr (Bureau of Animal Industry, Washington, D. C.), Referee. The work has consisted of the examination and criticism of the report of the Committee on Fats and Oils of the American Chemical Society. This committee has recommended a set of uniform methods for the sampling and analysis of fats and oils to be used by members of the American Chemical Society. The report shows divergence in some respects from the methods adopted by this association but appears unlikely to lead to any actual inconvenience or confusion except in one respect. This is in the method proposed for the determination of the iodin number. The committee has adopted the Wijs method for the determination of the iodin number! instead of the well-tried Hanus method’, now official in this association and in the American Society for Testing Materials. The committee appears to consider that the Wijs method has certain advantages which make its adoption advisable, even at the cost of causing the confusion which will inevitably result from the use of two methods which do not always give identical results by the different societies. In the opinion of your referee, the advantages of the Wijs method are not substantial and the adoption of the Hanus method by this association was justified in the light of present information as well as information available at the time of its adoption, and such advantages as are possessed by the Wijs method are more than over- balanced by the disadvantages of having two different official methods. Since, however, the Wijs method has been definitely adopted by the Fats and Oils Committee and will be official in the American Chemical Society, this condition of confusion must inevitably occur and can not be prevented by this association. The following recommendations are offered for the purpose of reducing this confusion as much as possible: RECOMMENDATIONS. It is recommended— (1) That the Hiibl method for the determination of the iodin number* be dropped from the official methods. 1 J. Ind. Eng. Chem., 1919, 11: 1161. 2 Assoc. Official Agr. Chemists, Methods, 1916, 305. # Tbid., 304. 524 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 (2) That the use of the Wijs method, as adopted by the American Chemical Society, be made optional under the official methods. (3) That all reports of iodin numbers specify the method used and where no method is specified it shall be understood that the determina- tion was made by the Hanus method. REPORT ON SPICES. By H. E. Srypatu!? (Austin, Nichols & Co., Inc., New York, N. Y.), Referee on Spices and Other Condiments. The work has been a continuation of the study of the referee’s modi- fication of the distillation method for water in whole spices and the tentative method for the determination of volatile oil in mustard seed’. MOISTURE IN PEPPER AND CLOVES. Samples of Zanzibar cloves and Lampong pepper were sent to six col- laborators, with a copy of the method, a photograph of the apparatus used by the referee, and instructions to follow the method as written and to determine the moisture also by the official method‘. Reports were received from three collaborators: M. B. Porch, H. J. Heinz Co., Pitts- burgh, Pa.; W. B. Smith, Armour & Co., Kansas City, Kans.; and F. M. Boyles, McCormick & Co., Inc., Baltimore, Md. The following method was sent: Place 50 grams of whole spice in a distillation flask with 150 cc. of kerosene; whirl the flask several times to bring the oil in contact with each particle of spice. Place the flask on an asbestos board, cut so that the bottom of the flask extends below the surface. Place a wire gauze with an asbestos center about } inch below the bottom of the flask. The object is t- keep the flame from direct contact with the flask. The asbestos board serves to keep the heat uniform. Connect the flask directly with the vertical condenser. Insert a thermometer through the stopper of the distillation flask extending into the oil. Adjust the flame so that about 20 minutes will be required to reach the temperature of 170°C., and collect the distillate in a graduated cylinder or burette. Extinguish the flame, after which the thermometer will show a slight gradual increase in temperature. As soon as the water stops dropping from the con- denser tube, which usually requires 4-6 minutes, the operation is complete. Multiply the volume of the water layer by 2 to obtain the percentage of moisture. The results obtained are shown in Table 1. 1 Presented by L. C. Mitchell. 2 Present address, Francis H. Leggett & Company, New York, N. Y. 3 J. Assoc. Official Agr. Chemists, 1920, 4: 149. ‘ Assoc. Official Agr. Chemists, Methods, 1916, 79. 1921] SINDALL: REPORT ON SPICES 525 TABLE 1. Moisture in pepper and cloves. MODIFICATION METHOD OFFICIAL METHOD* ANALYST ] Cloves | Pepper Cloves Pepper per cent | per cent per cent per cent Mme borelce enti so ae. seca ec hs } 6.4 | 7.4 8.94 9.98 Wide Shit! ae wz | 7.0 9.13 12.30 aod ee aad haere 6.21 | 10.09 7 Mba ee 7.5 8.2 8.94 11.59 75.o|0 685 ath ah | Pepeoundallsest see ee eee en Ae | St S72 et OG2 * Assoc. Official Agr. Chemists, Methods, 1916, 79. DISCUSSION AND CONCLUSIONS. These results show a difference of 1.1 per cent in both cloves and pepper by the distillation method, and a difference of 2.92 per cent in cloves and 2.68 per cent in pepper by the official method!. These results demonstrate that analysts can obtain closer results by the distillation method than by the official method. VOLATILE OIL IN MUSTARD SEED. Samples of ground California brown mustard seed and ground char- lock seed were sent to five collaborators with the request that they be examined by the method printed in Service and Regulatory Announce- ment No. 20? and also by the method given in Leach*. The following method was used: Place 5 grams of the ground seed (No. 20 powder) in a 200 cc. flask, add 100 cc. of water, stopper tightly, and macerate for 2 hours at about 37°C. Then add 20 cc. of U.S. P. alcohol (95%), and distil about 60 cc. into a 100 cc. volumetric flask containing 10 cc. of 10% ammonium hydroxid solution, taking care that the tip of the condenser dips below the surface of the solution. Add 20 cc. of N/10 silver nitrate solution to the distillate, set aside overnight, heat to boiling on a water bath (in order to agglomerate the silver sulphid), cool, make up to 100 cc. with water, and filter. Acidify 50 cc. of the filtrate with about 5 cc. of concentrated nitric acid and titrate with N/10 ammonium thiocyanate, using 5 cc. of 10% ferric ammonium sulphate solution for an indicator. Each cc. of N/10 silver nitrate consumed equals 0.004956 grain of allyl isothiocyanate. The results obtained are shown in Table 2. 1 Assoc. Official Agr. Chemists, Methods, 1916, 79. 2U.S. Dept. Agr., S. R. A., Chemistry, 20: (1917), 59. ?A.E. Leach. Food Inspection and Analysis. 3rd ed., 1913, 457. 526 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 TABLE 2. Volatile oil in mustard seed. 8. R. A. METHOD LEACH AES California Charlock California Charlock seed seed seed seed per cent per cent per cent per cent W:: Bo Smiths 234 eee oe os ec 0.95 0.258 0.81 0.17 0.95 Hee a Bose B. MaBoyles. Fa. ake seser actos 0.856 0.192 0.893 0.207 0.856 0.192 0.916 0.197 Louis Schwartz, U. S. Food and Drug 0.86 0.81 Inspection Station, Transportation Building, Chicago, I. RECOMMENDATIONS. It is recommended— (1) That the modification of the distillation method for the determina- tion of water in whole spices be further studied for one year, with particular reference to temperature necessary to drive over all the water, and length of time required. (2) That the tentative method for the determination of volatile oil in mustard seed be adopted as an official method. No report on cacao products was made by the referee. REPORT ON COFFEE. By H. A. Lepper (Bureau of Chemistry, Washington, D. C.), Referee. At the last meeting of the association, the Fendler-Stiiber method for caffein in coffee was tentatively adopted with the further recommenda- tion that the method be studied with a view to its adoption as official. Before adoption as an official method, it was deemed advisable that the method be studied in detail, as well as through the analyses of collabora- tive samples. The important steps in the procedure, the extraction including the filtration and the manipulation of the filtrate, the oxida- tion with potassium permanganate and subsequent treatment with hydrogen peroxid, and the drying of the caffein, were studied. These steps were considered in their reverse order as verification of each succeeding last step was necessary before the preceding step could be studied. 1 J. Assoc. Official Agr. Chemists, 1920, 4: 216. ba | 1921] LEPPER: REPORT ON COFFEE 52 DRYING THE CAFFEIN. Conflicting statements have appeared in the literature regarding the drying of caffein previous to weighing. Beitter’ recommends drying at 85°C., owing to a loss of caffein at higher temperatures. Hartwich and Du Pasquier? found in drying caffein at 100°C. a loss of 0.4 per cent per hour. Blyth’ claims that caffein begins to sublime at 78.8° to 79.4°C. and hence can not be dried at 100°C. Many authors‘, however, give data showing that there is practically no loss when a chloroform solution of caffein is evaporated to dryness and dried for 30 minutes in a water oven, as directed in the method. In view of these conflicting claims, experiments were conducted to determine if the procedure of drying, as directed in the method, showed a loss of caffein. Caffein dried to constant weight in a water oven was weighed and dissolved in 150 cc. of chloroform in a tared flask. After the chloroform was evaporated off on the steam bath, the residue was dried for 30 minutes in the water oven. Three separate quantities of caffein, 0.3304, 0.3095 and 0.2004 gram gave a weight of 0.3303, 0.3096 and 0.2004 gram, respectively. It was found that the chloroform could be evaporated to a small volume and the solution transferred to a small beaker with chloroform, the evaporation completed and the residue dried for 30 minutes in the water oven, without loss of caffein. The length of time used in drying was always found to be sufficient to obtain constant weight. This procedure of drying has also been recommended recently by Power and Chesnut®. The advantage of transferring the residue to a small beaker allows the weighing to be conducted in a small vessel, which is of special advantage on a humid day. The method was modified to include this procedure. All weighings of caffein reported in the remainder of this report were so conducted. THE OXIDATION WITH POTASSIUM PERMANGANATE. Fendler and Stiiber® adopted the permanganate purification of Lend- rich and Nottbohm’ and accepted the results of their investigation as to the negative action of potassium permanganate on caffein without further verification. The latter authors were the first to use permanga- nate for the purification of caffein but had some doubt as to their priority. Their doubt was founded on a note® which stated that a method of Markownikoff presented to the Russian Chemical Society used man- 1 Ber. pharm. Ges., 1901, li: 348. ? Apoth. Ztg., 1909, 24: 120. 3M. W. Blyth. Foods, Their Composition and Analysis. 6th ed., 1909, 324. 4 Ber. pharm. Ges., 1902, 12: 250. Pharm. J. Trans., 1892-3, 3rd ser., 23: 213. Pharm. Review, 1905, 23: 305. Forschb. iiber Lebensm., 1897, 4: 78. 5 J. Am. Chem. Soc., 1919, 41: 1298. & Z. Nahr. Genussm., 1914, 28: 9. 7 [bid., 1909, 17: 241. 3 Bull. soc. chim., 1877, 27: 266. 528 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 ganese as a purifying agent in the determination of thein in tea. How- ever, a similar note! states that the method of Markownikoff used magnesia. Neither of these notes made reference to an original article and Lendrich and Nottbohm state that they were unable to consult original Russian publications to clarify the discrepancy. An article by Markownikoff?, published in 1876, on the determination of thein in tea was found by the referee in which the use of magnesia was recommended. Other attempts to find publications wherein the action of dilute potassium permanganate on caffein in neutral solution was studied met with no success. In view of the fact that the work of Lendrich and Nottbohm appeared to be the only record of study of this procedure, it was deemed advisable to verify, if possible, their conclusions. Accordingly, a solu- tion of 4 grams of dried caffein in 1 liter of water was prepared. Three 50 ce. aliquots were treated with 20 cc. of 1 per cent potassium perman- ganate for 15 minutes at room temperature, as directed in the Fendler- Stiiber method. After the excess of permanganate was destroyed with hydrogen peroxid and the solution heated, it was filtered hot with suction and the filter washed with hot water. The solution was then extracted with seven 25 cc. portions of chloroform and the combined extractions evaporated and weighed. Two 50 cc. portions were similarly extracted and weighed to establish a blank on the caffein solution. In the case of the untreated solutions, 0.2004 and 0.2003 gram of caffein was recovered, while in the case of the treated solutions 0.1979, 0.1977 and 0.1972 gram of caffein was recovered. In each case the manganese dioxid which was filtered off was dissolved in acetic acid, the acid neutralized and the solution extracted with chloroform to determine if caffein was retained in the manganese dioxid. No weighable residue was obtained in any case. Moreover, the solutions of caffein that had been treated and extracted were re-extracted with four, 25 cc. portions of chloroform and no weighable residue was obtained. It is indicated, therefore, that a loss of from 2.1 to 2.8 mg. of caffein was due to oxidation which, on the calculated quantity present before treatment (0.2000 gram) is about 1 per cent. A loss of this magnitude in the quantity of caffein present in coffee would mean that the result would be 0.01 to 0.015 per cent too low. Permanganate, as is well known, acts on a great number of organic compounds to a greater or less degree, depending on the concentration, temperature, time and the reaction of the menstrum. Accordingly, experiments were performed to establish if the loss observed above was a real loss. As the purification of the caffein is carried out in neutral solution, no study was made in acid or alkaline menstrums. The con- centration used in the method is just sufficient to give an excess of per- 1 Ber., 1876, 9 (II): 1312. 2J. Russ. Phys. Chem. Soc., 1876, 8: 226. 1921] LEPPER: REPORT ON COFFEE 529 manganate with the quantity of sample used and therefore no study was made with a view to changing this factor. Weighed quantities of caffein were dissolved in 80 cc. of water, treated with 20 cc. of 1 per cent potassium permanganate and allowed to react at room temperature for different periods of time. At the end of the time hydrogen peroxid was used, the caffein extracted and weighed. The results are given in Table 1. TABLE 1. Effect of time on action of potassium permanganate on caffein. TIME OF REACTION CAFFEIN USED CAFFEIN RECOVERED Loss hours gram gram gram 3 0.2013 0.1982 0.0031 4 0.2021 0.1960 0.0061 i 0.2016 0.1959 0.0057 1 0.2016 0.1927 0.0089 48 0.2000 0.1319 0.0681 48 0.2000 0.1389 0.0611 Weighed quantities of caffein in 80 cc. of water were also treated with 20 cc. of 1 per cent potassium permanganate at the temperatures of ice and steam baths. After reacting for the time specified, the excess of potassium permanganate was destroyed with hydrogen peroxid, extracted and weighed. The hydrogen peroxid was added to the cold or hot solu- tion, as the case might be. The results are given in Table 2. TABLE 2. Effect of temperature on action of potassium permanganate on caffein. CONDITION OF REACTION TIME pee es Loss minutes gram gram gram LOE ETAL 5 Sates Oe ee een eee ee 15 0.2000 0.1999 0.0001 Reeqpathmyrnsr tes. cots cece a 15 0.2000 0.2005 0.0000 Reesbacurae ols ess tet theh. oc } = CS) > °o = i} 5 So S & o me io) & ie) me o & per | per per per per | per per per per | per cent | cent | cent cent | cent | cent | cent cent | cent | cent Darling’s Grain Indiana |0.82/0.91)11.00)12.55)2.00/2.90) 9.00) 9.65)1.00)0.88 Grower 1-9-1 Missouri 0.82/0.99/11 00/12. 2912 00/2.70 9.00} 9.59}1.00)1.07 Read’s Sp. H. G. Indiana |....|..../18.00/21.51]... .|5.18]16.00]16.33]....].... Phosphate 0-16-0 | Missouri |....|..../18.00/21.68)....}4.70)16.00)16.98)....|.... Read’s Blood and | Indiana _ |1.65|1.62)..... 12.88]... .]3.85) 8.00} 9.03/2.00)1.78 Bone 2-8-2 Missouri |1.65/1.55]..... 14.05)... .|4.21] 8.00} 9.84/2.00)1.87 Swift’s Diamond K | Indiana _ |0.82/0.86)..... 13.56]... .|1.27)12.00]12.29]1.00)0. 83 Grain Grower Missouri |0.82/0.94)..... 13.77]... .|1.26)12.00}12.51/1.00)0.86 1-12-1 Swift’s Corn and Indiana /|1.65/1.49]..... 12 (60/5. . WL 30/10 00/252 ea eee Oats Special Missouri {1.651.438}... .. 12.89]... .|1.47}10.00)11.42)....].... 2-10-0 Swift’s Diamond Indiana /|1.65)1.43/11.00)12.37|3.00|/3.50} 8.00) 8.87|3.00/2.62 W Tomato and | Missouri |1.65/1.35/11.00)12.39/3.00/3.64| 8.00] 8.75)/3.00|2.64 Vegetable Grower 2-8-3 Swift’s Bone Meal} Indiana _ /|0.82|0.74/20.00/21.69)7. and Phosphate | Missouri |0.82/0.68)20.00/21.31/7 1-13 oc 1 oo _ _ w (=) (=) _ ww ie) (0%) While some difference may be observed in certain cases, there is only one result—that on potash in the first sample—which means a difference of being over or under the guaranteed value. Some practical difficulties have also been observed with the double tube sampler, which should be mentioned. The diameter of the Indiana sampler is about 27 mm., which makes it difficult and at times utterly impossible to insert in a sack of fertilizer of a sticky nature, such as acid phosphate. Then, again, the amount of fertilizer removed is such that, when 10 sacks of the brand have been sampled, the amount is so large that it must be mixed and quartered before a sample of cenyenien size can be obtained to be carried away. With the Missouri sampler, 1921] HAIGH: A TRIAL WITH TWO TYPES OF FERTILIZER SAMPLERS 599 all the sample obtained is carried away and no quartering is necessary. In using the double tube sampler, fine particles of fertilizer work in between the two tubes, and after the tube has been once inserted in a sack and withdrawn with its load it must be pulled apart and all of this fine material shaken out with the sample before it can be used a second time. This fine material scratches the tubes severely, making them work more and more loosely together, thus admitting more fertilizer between them and increasing the difficulty of using the sampler. An effort has also been made to adapt the double tube sampling idea to the Missouri sampler. Such a sampler is now being tried out, and it is thought that with the removal of one or two mechanical difficulties it may be freed from some of the practical difficulties of the Indiana sampler. These data are presented at this time to show that the Mis- souri sampler is free from the objection of the other open types of sam- plers, such as the butter tryer type, which fills as it is pushed in and empties itself when withdrawn. The pointed end of the Missouri sampler pushes away the fertilizer from the groove as it enters, and when the sampler is withdrawn the contents of the groove can not be pushed out, as the end of the groove is not open in the longitudinal direction. In this way it resembles the operation of the double tube sampler. It is recommended that a further study be made of samplers and methods of sampling, as it is believed the discrepancy in results in the analysis of fertilizers has largely grown out of the difference in the samples obtained. THE DETERMINATION OF BORAX IN FERTILIZER MATERIALS AND MIXED FERTILIZERS.'! By G. F. Lipscoms?, C. F. Inman*and J. S. Warxrns?’ (Agricultural Experiment Station, Clemson College, S. C.). Owing to the large amount of damage during the past season to grow- ing crops in this State, apparently from some ingredient in commercial fertilizers, and in consequence of the wide-spread belief that the damage was caused by borax known to be present in some of our American potash salts, it became necessary to develop some method for the determination of borax in fertilizer materials and in mixed fertilizers. There are two well-known methods in use for the determination of boron: A gravimetric method worked out by Rosenbladt and Gooch; and a volumetric method, sometimes called the glycerol or mannitol 1 Presented by R. N. Brackett. 2 Present address, University of South Carolina, Columbia, S. C. 3 Present address, Greenviile, S. C. 4 Present address, Department of Agriculture, Commerce and Industries, Columbia, S. C. 600 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 titration method. Many trials of the Gooch method, and combinations of this method with the titration method, seemed to show that distillation methods were not suitable or convenient for routine work. The volumetric method takes advantage of the fact that boric acid reacts neutral to methyl orange, but is acid to phenolphthalein, and may be quantitatively titrated in the presence of mannitol or glycerol, which prevents the hydrolysis of sodium borate. This method is not, however, applicable in the presence of certain impurities, notably phosphates, ammonium salts and organic matter, and hence can not be used with fertilizer materials or with mixed fertilizers containing one or more of these impurities. This volumetric method appeared to afford the best basis for the development of a rapid and accurate method for the deter- mination of borax in fertilizer materials, and in mixed fertilizers, since it offered a means of removing the interfering substances without loss of boric acid. The following method has been developed: REAGENTS. (a) Saturated solution of lime water. (b) Standard solution of pure borax, or of pure boric acid. (C) N/10 solution of sodium hydrorid—Carefully standardized against the borax solution. : (d) Hydrochloric acid about N/10. (€) Neutral glycerol or neutral mannitol. (f) Methyl red 0.1 gram in 100 cc. of hot 50% alcohol. (Acknowledgment is made to W. H. Ross, Bureau of Plant Industry, Washington, D. C., for suggesting the use of methyl red in place of methyl orange.) (8) Phenolphthalein 1 gram per 100 cc. of alcohol. PREPARATION OF SOLUTION. Weigh 10 grams of the sample and transfer to a 500 cc. graduated flask, add 200 ce. of water, and boil the contents of the flask for 10 minutes, after which cool the flask and make the contents to volume. Or, weigh 2} grams and wash on a filter paper with hot water, collect the washings in a 250 cc. graduated flask, cool the flask and contents and make to volume. If the total boron is desired, digest 10 grams of the sample in a 500 cc. graduated flask for about 30 minutes with 200 cc. of water and 15 cc. of hydrochloric acid (1 to 1), then cool the flask and make to volume. (a) Materials free from ammonium salts, phosphates, and organic matter.—Transfer an aliquot corresponding to 1 gram of the sample to a wide-mouthed 200 cc. flask, acidify with N/10 hydrochloric acid, using methyl red as the indicator, connect the flask with a reflux condenser and boil the contents for 10 minutes to remove carbon dioxid. Cool, make neutral with sodium hydroxid, in the presence of methyl red, add 30 cc. of neutral glycerol, or 1 gram of mannitol, and titrate with N/10 sodium hydroxid in the presence of phenolphthalein'. 1W.W. Scott. Standard Methods of Chemical Analysis. 2nd ed., rey., 1917, 76. —————— eC —, ——————————— 1921] LIPSCOMB, INMAN, WATKINS: BORAX IN FERTILIZERS 601 (b) Materials containing ammonium salts, phosphates, and organic matter —Bring the -sample into solution as described in (a). To insure the complete removal of ammonium salts, make the aliquot, corresponding to 1 gram of the sample, alkaline with sodium hydroxid and boil nearly to dryness, then dilute with water and repeat the same operation at least twice. Take up the residue with water and make the solution slightly acid with hydrochloric acid (1 to 10), using methyl red as the indicator. Then make the solution alkaline with lime water, and, after stirring vigorously, filter off the phosphates, if any, and wash five or six times with warm water. The solution must not be boiled after the addition of the lime water, as insoluble calcium borates are formed. Collect the filtrate and washings in a 200 ce. wide-mouthed flask. Evaporate the solution to dryness in a porcelain or platinum dish on a water bath, and ignite over a Bunsen burner to remove the organic matter. Dis- solve this residue in a little dilute hydrochloric acid, make alkaline with lime water, filter, make the filtrate acid with N/10 hydrochloric acid in the presence of methyl red and wash into a 200 cc. wide-mouthed flask, finally making to a volume of about 150 ec. Connect the flask with a reflux condenser and boil the contents 10—15 minutes to remove carbon dioxid. Then cool the flask and contents, make the contents neutral with N/10 sodium hydroxid, using methyl red as the indicator, add 30 cc. of glycerol, or 1 gram of mannitol, and titrate the solution with N/10 sodium hydroxid, using phenolphthalein as the indicator. Then add an additional 20 cc. of glycerol, or 0.5—1 gram of mannitol and continue the titration to conclusion. A blank should, of course, be run with the reagents and deducted. This blank may amount to as much as 0.12 per cent. No report was made by the Committee on the Revision of Methods of Soil Analysis. R. N. Brackett: I would like to ask a question. The association has changed the assignment of referees’ work and has appointed referees and, in some cases, associate referees, and they have been assigned certain topics. Are the associate referees to send a statement to the general referee of what they are doing, or is the general referee to send them a statement of what he wants them to do? Just what relation does the associate referee bear to the referee? C. L. Alsberg: The idea, as I understand it, is this: The general referee will be a man who will keep in touch with the progress of the work covered by this particular subject during the year. He will be an older and more experienced man and will keep his finger on the pulse of developments. If any condition arises in his line of work which demands investigation of the type conducted by the association, he will have full authority to appoint an associate referee who will do it under his direc- tion. If, on the other hand, he does not feel that the subject is urgent and that it must be investigated at once, he should make a report to the association at its next annual meeting that such and such a subject should be studied. His report may be that nothing new has turned up in the year that is worthy of the attention of the association. It is also important that he shall direct and supervise the work of his associate referees. The idea is to get away from having, year after year, a referee 602 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 who feels himself under obligations to report on a subject in which, perhaps, nothing new has arisen. Under the old procedure he would merely report that nothing special had turned up and that he had no recommendations to ntake. The idea is to get away from this perfune- tory work. P. F. Trowbridge: The referee is in charge, then, as I understand it, and is at liberty to appoint associate referees to assist him in his work should circumstances arise during the year to warrant such action. C. L. Alsberg: Yes. REPORT OF COMMITTEE ON RESOLUTIONS: Resolved, That the thanks of this association be extended to the New Willard Hotel for the use of rooms for meetings, and the excellent arrange- ments for conferences and committee meetings. Resolved, That the association. hereby expresses to President Trow- bridge its appreciation for his unfailing courtesy in conducting success- fully the affairs of his office. Respectfully submitted, W. D. Cottins, H. B. McDonneE Lt, JuLius Hortvet. Adopted. President Trowbridge: 1 desire to announce to you thus officially the passing of five of our active members since we met last in regular annual session as an association. Please rise and do honor to them as I call their names: WALLACE C. BurRNET. ALBERT F, SEEKER. Cyrit G. Hopxins. James H. SHEPARD. Martin N. STRAUGHN. ALBERT FREDERICK SEEKER. The subject of this sketch, Albert Frederick Seeker, died on August 19, 1919, from complications following an operation for appendicitis. At the time of his death, he was Chief of the New York Food and Drug Inspec- tion Station of the Bureau of Chemistry. Mr. Seeker was born at Brook- lyn, N. Y.,in 1878. His parents died during his early childhood, and he was obliged to earn his way through the various educational institutions he attended. After completing the grammar school course in Brooklyn, 1 Presented by H. B. McDonnell. ALBERT FREDERICK SEEKER. (See Page 602.) 1921] DOOLITTLE, DUNBAR: OBITUARY ON ALBERT FREDERICK SEEKER 603 he entered the New York College of Pharmacy with the intention of adopting pharmacy as a profession. His studies at that institution developed an interest in chemistry, which became his life work. Upon completing the course in the College of Pharmacy, he entered the Brook- lyn Polytechnic Institute, from which he received the degree of B. S. in 1902. After engaging in tutoring for about a year following his gradua- tion, he entered the laboratory of the Brooklyn Navy Yard in April, 1904, as assistant chemist, and in June, 1905, at his own request, was transferred to the New York Food and Drug Inspection Laboratory of the Bureau of Chemistry, with which laboratory he was associated dur- ing fourteen years of the most able service ever rendered by a public official. Throughout life Mr. Seeker was a constant student of chemistry; few men have a more intimate knowledge of every branch of the science. His interests did not stop with chemistry, however. He was an inveterate reader, not only of the chemical literature of France, Germany, England and America, but of all good literature. As an analyst, he can only be described as brilliant. He was an adept in devising methods of analysis, and a long series of methods in daily use in food and drug laboratories in this and other countries attest his ability in this direction. During the fourteen years of Mr. Seeker’s connection with the Bureau of Chemistry he was a tireless worker in the Association of Official Agricultural Chemists, serving nearly the entire time as referee or associate referee on various food products. Perhaps his most valuable contribution to the associa- tion was as a member of the recent Committee on Editing Methods of Analysis. The value of his services in connection with this publication can not be overestimated. His thorough knowledge of the principles of analytical chemistry, and his personal familiarity with many of the methods themselves, was such that his suggestions and advice prevailed throughout the work, and it is not too much to say that whatever value can be claimed for the revision is due to a great extent to the contribution of his time and experience. Mr. Seeker had an enormous capacity for work, and his activities in connection with the revision were carried on without interrupting the task of administering the largest laboratory unit in the Bureau of Chemistry. Mr. Seeker was a member of the American Chemical Society, the Soci- ety of Chemical Industry and the American Association for the Advance- ment of Science, and took an active interest in these organizations. He served for many years as an abstractor for Chemical Abstracts. He collaborated with John C. Olsen in the preparation of Van Nostrand’s Chemical Annual, compiling for that publication many of the tables of physical and chemical constants. He also contributed the Chapter on Coloring Matters in Foods to the Fourth Edition of Allen’s Commer- 604 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS [Vol. IV, No. 4 cial Organic Analysis, Volume VY. His publications in the various chemical journals cover the whole field of food analysis. Although Mr. Seeker’s tastes and training were primarily in the direc- tion of analytical chemistry, the necessities of the service threw him more and more into administrative lines as time went on, and in these he showed a capacity hardly less marked than in the lines of laboratory work. He was a most able chemical witness. His testimony was clear and concise, and continually earned the approbation of Federal judges and United States attorneys. Above and beyond all else, his character as a man has made his loss a source of the profoundest sorrow to all who knew him. It was said of him that he was “good, true, brave, clean, honest, able; that no one ever asked for help, or was in trouble, but he gave unselfishly to the utmost of his great ability.’’ His home life was characterized by a tender and loving devotion to his sister, the only surviving member of his family. He was the soul of honor in all his dealings, sympathetic to those in trouble, a loyal friend, a wise and conscientious adviser, possessed of a deep sense of humor, a delightful companion. No man in the Federal service was ever accorded more ungrudging personal affection, and no chemist in the service was ever held in higher appreciation by reason of his scientific instincts and attainments. He believed and proved that the best his ability had to offer was not too much to put into the service of the public. His best will always be an unfailing source of pride to those with whom he was associated. R. E. DoouittLe. P. B. DunBarR. C. L. Alsberg: I can not urge too strongly upon referees the importance of sending their annual reports to the secretary’s office considerably in advance of the meeting, in order that they may be circulated among the members with a view to later discussion at the meeting. It was moved, seconded and adopted that the time and place of the next meeting be left to the Executive Committee with power to act. The convention adjourned. INDEX TO VOLUME IV. PROCEEDINGS OF THE THIRTY-FOURTH ANNUAL CONVENTION, 1917, AND OF THE THIRTY-FIFTH! ANNUAL CONVENTION, 1919. Address PAGE Lr IR Reaves Oi Ses Gs G0 Ae Oe ely eo Oran ACEC AM nym ire whrid Pe ELesid CD bry ote esi esalom Peper eivee Soetcrere aisto 2 3/0 ree item 311 EVA leave GNOLALY, ELCSICGING ais 1c eters) no olaceh yay. cle roynie sia Dacre 2:55 dc lee oie Aes 184 HELSTOTICD oa eS OR mIOSe Rex tas a pact Bact cian Ronen Ree ria Occ 463 Alcoholic beverages. See Distilled liquors. Alcohols pharmacopeeial assay in santal oil extended to include the true acetyl value, PIAWOLLOY EV ArriSOMey'. siege cus, afe sis crys Sieh eres eles siemieiaya, #16 crisis ay syere olin: sie 425 Alkaloids cinchona, identification of, by optical crystallographic measurements, paper by WiherryarndsVanovsky.relerences < sac... a) cefud esas s15 eC Oa ere aleve os recommendations VA ESHSH rains, steep aye in ete «= Oye ee ro aye le oR ea ehe Shek leas cach Miele cones uelnssts 416 Byg@ommmitibee bs ayers Scares stares co tae seek eT aresele oe Lon S Ss eats seeb reps 249, 572 byeHuller Syn ee ee Cone SLE ee Me oe roraciaeaichuties sysiatalate crs 156 report LOLS Tse ee SO Cb BE ee COE SE aE ESO Sac HE Oe aeMSn 416 lon LRU 2 oe Se tig’ aaa ce bee Soca ane net arin eerie ine 156 Alsberg report CHEE OSLO M OES EAEBEOTS oe acco coy aise sacle c/n) oo) whose) «leiiaré isles Bese sovetolene ialsceuanaks © 272, 554 of Secretary-Treasurer for two years ending November 19, 1919..................-+---+> 552 fonsvear ending. November 21 S190 1.2 sc: sacs <8. 4)+ san oe ete ee wine ies 270 OTE GCD QUIET Peps est hs oe) ciSee eae Sev ie egevege Sibi od wihetane oa cveney Spe bycysucks eyes 272, 554 Arsenate . calcium, determination of water-soluble arsenic oxid, paper by Graham...... 406 calcium and magnesium, solubility in carbon dioxid and its relation to foliage MOY APADCEMD Vat AULe Mey yvo een io mise ci crass ere re Cae Bie Sosnte is svn ieccisingere; oars 404 Arsenic, determination in insecticides by potassium iodate, paper by Jamieson, OPC ECROG Sa an sere pao ele ceeds eae acorn ee aac Sees ss Ete ees eae 147 determination in cane sirups and molasses _ recommenda tous Dy ZELban a) << < c.teial= cos, cte is) vids piste) <'e whch oVolsi syne eel eve eter e re 451 BEHOLD NE ACE ADE Ly tere eee rte te ic cee. cc von cc eine etebers 444 Associate referees, officers, referees, and committees foutworyearsienaine November, 1919005.) 2 ein les ncesl gies oan one 1 For vearenume November; 1920! 01 ose coe oe cles ogee teeratcl eects 299 Attendance RUBE AA CONVEMUIOM § jc, 5y5 5. ci2) «51 2 egdyagatchs clo cncueusvepeucepestaganse to eyed ees ore oe 5 BEE LeRA a) COTA CEPELOEN © 2 occ 55245 2) sade oscie len No psreys ce es Be Nee, RRS Biche Hat ages heart as 304 Auditing committee PMBOUMUNENH AUG: PETSODNEL 73 are /aro-s a Ss aysiriere sie wise ts PTS Pais 63, 364 report...... ee Saye ia ares See Te wie CS Se EOE Ce ale 71, 553 Bailey, C. H. paper, physico-chemical methods for determining the grade of flour.......... 456 Bailey, E. M. CH OLESG LGA rey tetas tostoreshd ie ats teratatenaic ot ols ote: Neicke elaratenie te a etare eds ee EBS OE 534 1 No meeting was held in 1918 other than a meeting of the Executive Committee. 605 606 INDEX TO VOLUME IV Baking powder EAGE behavior of neutral ammonium citrate in certain phosphate solutions, paper by Patten.and: Mains 5.5. 25 ak cannon te ee Rn ee 235 changes 'inimethods+ a: Gy. ee At 5 A So at es ee 268, 550 recommendations by ‘Gommittee! Gee) 2... Sea Se en te 257, 585 by Patterns 2x5 ce Hane etapa: staret er Sarat: hy ee een es fe ors a 232, 539 Report: Dy Patent go seca 0 si cristae aes re OE nor ee 217, 538 Balsam, Gurjun, Turner reaction, paper by Luther....................--.2000- 422 Balsams and gum resins recommendations by Committers Be ett ace es es Se ee eee 249, 574 hyaGrant: mise iguanas alesis sal ose On SEs epee eee 421 report by Grant i 2 oe selec ele tale cies 3 estes ous ¢ Sose RENO See 421 Basic slag vegetation tests on availability of phosphoric acid recommendations: by Gommuttee Au 50. oe 23.05 sree. tos eee ee 563 report byicomumittee (Hartwell). sao ce «eee eee 286 Bates and Jackson, paper, densimetric and polariscopic standardization in reference to\the associate referee's report.on sugars... eee. 2 Jeo eee eee 330 Baumé scale committee, appomtment and! personnel’. «35... .- <2 e090 snes eee 365 report: of special committees") ore of ae ce ee nce e eee 551 Beers chanigesiin methods. ....< 542 5 <.5 ss: 3 3 hoch aenode es eee oe oe Oe 264 recommendations by Gommittee Gi... 2222... s <2. este eee eee 578 Benderreport\on ‘vinegars 5 245.5. .5522 02 oe eee eee eee ee eee 466 Beverages, non-alcoholic. See Soft drinks. Bidwell) report, foods and feeding stulis...-- occ oso so cee ose oe Cees Oe eee eee 321 Bigelow,:report; canned foods. 52 ex. ysis See ee CO Oe ee eee 179 Bliss, ‘reports alkaloids: 35 +42 05% 2,053 tae: asso oe ee ee ee eee ee 416 Borax in fertilizer materials and mixed fertilizers, determination, paper by Lipscomb, Inman, and Watkins 3525.5 <:0:s0e¢ sSeeesw ok Sos eet oe oon Sena ee eee ee 599 Brackett: presentation of pavel-ia 565225 2545 520520 ceR te ee ee 273 Breazeale, report, determination of calcium in the presence of phosphates......... 124 Brewster; recommendations/onienzyms-) >. +)... 22s See eee eee 425 Browne, paper, attitude of New York sugar trade upon the new Bureau of Standards value for’ standardizing saccharimeters:. 2-5: (3.25322. -cce so eee eee 334 Bryan; report, sugar: ..4 si .o0. is cass is sha nen ees oot Cee en ene ae 321 Butter, standardstadopted (&2 .. sas. se BLS Le I ee ee 590 By-laws, committee on amendment discharged........................------- 237 Cacao products changes mumethods 3 s...3 2. ascer eacGa hh wating oe - Se eR eee Bee 267 recommendations by Gommittee! G2... J. se alas ee nee ee ee 256, 584 Calcium, determination in presence of phosphates, report by Breazeale.......... 124 Canned foods . changes in'methods. 4.3... 220. soon sock ba cenne so ede as Seaniat ae eee 262 recommendations by Gommittee Gene - 25.5 .c. esse ele ee eee 253, 576 report by Bigelow:..\ =...) 02. os6.<4 + oS4mehe teeiie nie eee LEE Cee 179 standards adopted !2.. 252). sie. sis ie Ses pene Alon oa who eee eee 276 Canned vegetables. See Vegetables, canned. Cereal products determination of water content, paper by Cook.....................-...-- 347 physico-chemical methods for determining grade of flour, paper by Bailey. ... 456 recommendations by Gommittee: G, s.2ijo4 2.3 0 Seite ee oe tnt ee ee 253, 577 by he Glere f.2% 22% ccs 6 MCS SEE ne a AIRC Re OO eee ea 183 reportiby Ge (Glerc : 22... acta os cin tee oe SRO 3s eee 180 Cheese, standards ‘adopted =. <:.1.0c os nace sare see trace Defra Renee 284, 588 Cheese and milk, separation of nitrogenous substances recommendation by’ Gommittee (By. << ojo). ses ag he eisai -ine - i ee 248 reportiby Vani Slykes 2000... scan Sas cern ond ots ie Oe ene rene Ooi a oe eee 211 Chemical reagents, testing recommendations by Committee Bess 05 sjncies Sa eee eee cok Cea eke ee 250, 574 By swine oss oows Se wes Oa re IE Chee en ee ee 60 report by Hiwinp : &.:so5c:5 6.052 Sas wc otek Ce Ree ee OEE fae eee 59 INDEX TO VOLUME IV 607 Chemicals PAGE methods for estimating limits of chlorids recommendations by Kebler and Heath.................. 0 cee eeeeenee 364 PEPOLUD VCE bler and) EIEAURS =~ | 6-5 mss cy sieicicio cicra em aseie skevouchamnvensberenerepererels 360 Chlorids in chemicals, methods for estimation recommendations by Kebler and Heath..................00eeeeeeeeee 364 TEPOLU DYE MeDIleG ands Heatley = 5 «aa trac setae) eteeres satin 6 sin Soke eee 360 Cinchona alkaloids, identification, by optical crystallographic measurements, paper bya hennypartiey anOveky= TELCreNCG: ys.cc ss :c'5.s 6 «ite sae cle maces acciotalscans eccteine mele Clarke paper, double moisture determinations in fertilizer materials................ 57 Keportawaber/in foods and feeding stufis. . 2.5.5.2 20. 8-0 eas oe ee cones 48, 344 Clerget divisor, evaluation and double-polarization methods for estimation of sucrose, paper by Jackson and Gillis, reference...............0 000 e ee eeeeeees 321 Coffee BHAI ESTE CUNO Setters. dcr care oS ay eva cal tate tvs a Manso he Dace iewadd d crn obeeeesions 268, 549 recommendations yi Gommrttee Cee. ooo) 2 hn ho < 9 leer aareh aay ate sp ha Oaars aia 257, 584 PWR P DEE so ee lerarertro shore Aue) Sire afalee tages ate aeivinS 22): '« oa Move wivedoheresbaye 216, 533 BERGE UD Vi EG DDE oF 1. (2505 «Sas wince Ges oreler ae eta ues tee celts at met aaa exeele 211, 526 Si laser PON INE LAS IT) LOOUS.. << 6 010 518,65 sia, ale eb a) sto araun, Wiel ao) RA UT ere fs 454 Coloring matters in foods recommendations by) Gommuttee Gi... 2.. ee Wee ccs ce neccene ee ween 252, 575 REPOLU Dep athe WSO Nie ss yc Le sat ee tea oe ears oes eee ee eee 171, 452 Committee A on recommendations of referees, report (Patten)............... 239, 562 Committee B on recommendations of referees, report (Lythgoe). ............ 245, 567 Committee C on recommendations of referees, report (Doolittle)............. 250, 575 Committee on amendments to constitution and by-laws discharged.............. 237 Committee on auditing AP POMNEN WAN pPerSONNE 21ers ers ay = 5 avn snes Sido. care aes nya 63, 364 RE DOD eyes es orate choise sibs aia eels ak wausie bieinieea bint aw Adee tte ele eens 271, 553 Committee on Baumé scale MBPPOMLMED Lian DEISOMNEH./.,, cate dels sroNe sins Fanos een seis Side Ben aeaton ee ee 365 EOD se cals CCI ea ie PERI RRG Dinig CSE ROCI EEE eee eee eee SIS ieee race 551 Committee on editing methods of analysis RCTIUENUEL Oe poe is ee PG ee ele woes sick cue amelie: cei els sep cle nee oe 237 PRE COE (LOSE PUN te) a a elie teencal re copieets cited MNO cABSn sean EY caches Sit -7 Reet hc ee a ae 258, 540 Committee on methods of sampling fertilizers to cooperate with similar committee of American Chemical Society, report (Jones)..............2...2-22-2--- 287, 594 Committee on nominations, appointment and personnel....................- 63, 364 Committee on recommendations of referees, report (Ross)................-- 239, 561 Committee on resolutions SP POMUMeEN Can NECSONNGLa ye eae rcee are eve Save stein - 2 te} oe ok thereon 63, 364 report Pyare D) onniel ee arta toler sha ete he sate ee Mees cae a oh 4b Ree let ae 602 PU NIVEREGHICL EP Pane ear otter eters ocean este aie os ea cie Se oe Mea nthe 297 Committee on revision of methods of soil analysis, report (Lipman)............. 289 Committee on vegetation tests on the availability of phosphoric acid in basic slag, PER ORU CEL AREWCL meet ween oe. fats rn Be ee er hw Sah lala erate ero ee an elolecs 286 Committee to cooperate with other committees on food definitions, report (URBAN 2s citi Ba 9 ticre cee PaO OE ee eee eI ee Reet 275, 586 Committee to invite H. W. Wiley to address the convention, appointment and EGS OTE? 3 So ak S Soi deer Rtnel eee RAL ee Paar aE io ee ie Ben ee ane 63 Committee to invite the Secretary of Agriculture to address the convention, appoint- THETA ANE DEISONTEG Le wey aoe erate calc”. heel se te coe Lee ee ae Omen 63 Committees, officers, referees, and associate referees fomuwonyeacs ending November 19192-25082 neces sn cletee Saeenre as eis sci 1 AOTSVEAeNN PINON EMmbeL:) LODO! <1 fas. lec lee elated a oe time cate stele bas 299 Condiments GLY ea it TNS See ie ee Ea Pee er eater Ee ata o.clecemae 267, 549 recommenaagons by Committee Cs. 2.2. dessa ance swe Meee EOD OS Constitution, committee on amendment discharged....................-.-..--- 23 Cook, paper, determination of water in cereal and meat products............... 34 Sieamprandumiicy standards adopted. «rte. co). vac. ott ee Ohio e ba one alc 28 608 INDEX TO VOLUME IV PAGE Crude fiber recommendations by Gommittee Bs or Ponape eres See eee cere ee 246, 569 by Haigh Ss. 52556 (2S Pee Saeete erre mee meee ese eee 337 report by: Hraneis.i)jc ssid diets @scre oh oe als Se ee ee ee ee 39 by Haighis es c8.x22.22.5 545 bie eer hae ee hn ea 336 Cryoscopic examination of milk paper by Hortvet)o ore ee cn so ohne tetas nre pee eee 491 recommendations by Hortvetiis: ssc cccscme tence eee ee eee eee ee 498 Dairy products butter. standards; adopted: ;a ase ie els Romie Gatiare none 184 Horne, comments on recommendations proposed by A. H. Bryan............... 335 Hortvet paper, cLyoscopiciexamimna ton) Of MNKs Veenrs, che voi, Seuere Gras A stone ett ss is oimeie 491 LE POLE GAIL, PLOCUCES Ean esr on kris 5 lerele eran alse cae ares erates oie teanee ee 201, 482 ioward report, miicroanslytical methods 4-0 os Iseeiss cen ote n- io sina s nee 60 Howard, Hartwell and Pember, paper, lime requirements as determined by the plant andi by theiehemisy ss) vctsrarse: 2~.¢--.-----ae--- = +s See 351 Meat and meat products changes'm. methods.) [5.24 a3 See EI SA at eves Ss Reet 266 determination of water content, paper by Cook........................-. 347 recommendations by Gommittee 'G. 2.0. 2 sak oc Cee aie eaters etste eel See ers Steen 580 by Hoagland: . .. is 6.6 cts os ces ces eles ee eee Oe 501 report/byeloapland:. ci. 2).)-2' 0. SA ten eerie ee else eee eee 499 INDEX TO VOLUME IV 613 PAGE separation of nitrogenous compounds recommendations bya Gommiittee! Gis se ste ard a fais oer Oe Cae Ie SUS Oe Ee 581 Dyahitchellir. Sey Savasre ge ea oyate Mercier PaeGne oslo a/ raat aT 506 SE POuUTD VoIVILGHENIE SS oe. Sac, ces eerie Sree eye eae oes Sea ae vee 502 Meat extracts recommendations nya @omimitteey Cg pastere erento eee oes BENG eis ofa, eerie a ees 581 Evin VECULROMIES sere) acc ate eee aera tte eee rn UR etue sine fe Sete net omenrie rafts 506 LOMO OVE VEOULLGH ets ace Cree a et Nea aan ck craycles thie Toys. edaseaetes ahecate pete 506 Meat problem, address by President Trowbridge. .....................eee cence 311 Medicinal plants recommendations Iya Gomimrchee Eyer Per errr oe oe tine ein arate etree lrezere deieieie gs 249, 572 VMN TCHOCV.Gl eset tere Taree Steies cvereieie is 2 save laveleydyeraxersgedaus Spa Merwe coe 155, 415 Racers Lane NACHO Gis oo: 6 aaa eRe ae Pe ic ea Ce Pte 149, 409 Melezitose crystallography of, paper by Wherry, reference..............-.00 00 eee eee 443 occurrence in honey, paper by Hudson and Sherwood, reference............. 443 Members and visitors ALON Oy BCON NEM CLOT, s21cr apo che 3 degen sea ar eicncueis ope Ne apse ease ehemheleebsce tusks ee ereae 5 SUF IMO CarnGitnte) Neem ac ecdn pecs cero sorcoU aaona Reap acim cd RAS Bor 304 Metals in foods recommendations Lay (OCG) LATE cone arches cea OI AERC ROK Chm octane CTC IOCRS Che RISING 455 bya Gommittec! Ck se nnkiy- cnr eae ey eh sca) eee ne SALE 252, 575 Lae TESTE Avan tate ee SAL ULL pate Reh MR bo eatin ay Aor eae mere 179 report Epyaemo lini mbes meter ys ersieta heen reve cre cea es Specks renereves ete tec ecal gears 454 (ORE TET | coy RC ee Pee eee Ee ereeet nn IU ba ad as sel ppe me Rese 172 Methods microanalytical recommendations bye ClOmMitleeIDecrta eee Ro nice renee oie oe « oie le iae eae se eae 250 I VAELOW AR Ga se ccicranste Pa tetay tence ties a ebrcserale ots cas acs1s-5 yeralis die chelate ot a3 63 Pasenilony Lk hae Aa canis tee koe booed osu agp oochesbenunos nas seee 60 of analysis committee on editing Continued t= were eee ees Fe we poe 237 GRSCHSN Ga Gi AM, Soe caus caso oc WU cocnaL cognpRapasomdongr gre 556 report of committee on editing (Doolittle) ....................... 258, 540 soils, report of committee on revision (Lipman)....................... 289 Microanalytical methods recommendations by GommuitteesB.n tie taceke edie septa: ance PEO, 250 Vr AO WAC rte ws oe iraic orehcr pone nay shoreva te opeie locale tees -o!ctieraga's oe aimee enone ts 63 Fepore DypllOwarde. sctis,: faccyais eee Needles syaun SISA are eT eee Pee Meta tees ate 60 Milk cryoscopic examination recommendations Dy HIOLUVEL. +e cle aes ee Salles oe ba eo dle naman Sak see 498 PEpPOLm by OLE VEl:. 62.525 ssxeticc Se ee ee ee eee ene 491 Milk and cheese separation of nitrogenous substances recommendations) by GommitteenB a 24% cece er Seema eee 256, 583 by Kenn n.cc apace ge) srs os nated cine elses mre eye we lo. n's Stason ee 523 report by. Kerr sc ccs tsniale has trates ovis aise casa SEIS See aie ae ee 195, 523 Olives, summary of Bureau of Chemistry investigations of poisoning, paper by DeBord;:;Edmondson:and|hhom: reference): .. ..0 «<= 4 s-eemaeiee wen ties seated ences te ae me 217, 538 Patten, H. E., and Mains, paper behavior of neutral ammonium citrate in certain phosphate solutions. ....... 235 hydrogen ion concentration at which iron is precipitated from hydrochloric acid solution by ammonium hydroxid, sodium hydroxid and hydrogen sulphid... 233 Paul report oni flavoring extracts. ase oee oe ere obec ete tae 468 Pember, Hartwell and Howard, paper, lime requirements as determined by the plant and) bythe chemis¢s.dio. Fats kos. Woe ot cei arisen emo net aes iene eateries 123 Phelps paper effect of glass-wool in the ferrous sulphate-zinc-soda method for nitrates. . .69 use of permanganate in the Kjeldahl method modified for nitrates....... 69 FEport OM MITOGEN so 67. oes Sas avis wiayens Seis wera eee sie aig Sloe oe elle tetetee tet ee 365 INDEX TO VOLUME IV 615 PAGE Phelps and Daudt, report, investigation of Kjeldahl method for determining nitrogen 72 Phelpaiand Haskins; report, nitrogen’s 3% 203i. (2221s = aie e's v= ws eee ee el 66 Phosphates modified method for determination of fluorin, paper by Wagner and Ross, refer- ‘ CNV S SAO PARED ROOM COCRCIS Sa oe Mane HSRC HS OOn as AONB EEOAG OS wade Aces. 8 precipitated, effect of mass and degree of fineness on the percentage of avail- able phosphoric acid paper by Haskins......... eats leteiesels [ous ASI Me © Gis oi Dam ase Bele aereaere 64 TECOMMHENG ALON DY, ELASKINSS 5-7 Sec acer rris asso cn rae eee olen ee aa 65 Phosphoric acid in basic slag, recommendations by Committee A..................2.-----. 563 in precipitated phosphates, effect of mass and degree of fineness PAPE) DYPEVASKING ee ciara ce Pe ee rates Sia sche NS te ysl shs ie apelers teres 4 64 recommendations Bay ENpisshearassect =f, cotati s= 5 sSinis 08 chet faln'=, aioisjaeatel dee erelbvela. soe 65 insoluble, in organic base goods, paper by Thomas, reference............... 66 TECOMIMENT AMONS DVR OGMImnIClee tae a. =.c oie - vs ways k= Se dium alfa em aee wale 239, 562 vegetation tests on availability in basic slag, report of committee (Hartwell) ... 286 Phosphorus TESHSTGetermMmalOon. Paper DY NOYES. s\:<.seyoci iets sceeier= Sis) « Slals estore aisies © oe 93 organic and inorganic, recommendations by Committee B..................- 246 Plant constituents, inorganic RsliTa pres STANME LOOUS 2) 4 .or: capes Nae PRO ote anata te charade , 0:0 oa pala sier oar ayaee ye ahah «fora oval aya eocage Pea o Rea ore 425 Secretary-Treasurer report for two years ending November 19, 1919 (Alsberg)...................- 552 for year ending November 21, 1917 (Alsberg).....................000. 270 Seeker, Albert Frederick, obituary by Doolittle and Dunbar.................... 602 MNEnwOGdacepokte MONE Yieis. 2x12 seers o/s cea Brera ais aloe ehace esos aceite eee eee 170 Sherwood and Hudson, paper, occurrence of melezitose in honey, reference...... . 443 Silberberg; report, stock feed adulteration: .:... 2.2.2. 52..053.. 5200.08 0s bee 41, 340 Sirdalexeportarspleesyn ol sr thse loka rene tates oks al osole ifs ata fethava/svetatote’a sterels dejel sts syeratecele 524 Sirups, cane and molasses, determination of ash TECOMMENG ANONS DYBZeETbANG-myete. ee aise aise oe so el oem eve oeies 2 451 TE POEUM VOLTA eer ee ais: ai sachs ot sh s\sr a. o/s ciate Pye tere ove) a) od wi n\ oye qeusies snfe nisvelMeresese 444 Skinner report form of report and recommendations of referees...................-... 560 Botte nna ksty pee. ere erie rsa ce Ree ee te Cie aerate eee 183 Smitheire poresrela uma 7c ts seiko Sea a eee ghetto att ae mae LS ee 520 NHellemepont-;maple productBy ccc. nryutare s ee ahr tee ea aires bee ee a eee 157, 42: Soft drinks recommendations: by; Committee! Owns ...6 255 solo sone cs eee eee 253, 577 TEPOLE yO ENIEL a. jst ateletet veh achettetcteh Pala = fee wh cPegan tee) tats Nota lateie spo aN aD let gs 183 SEANGATUSAU OLE seit ere ee Chern be oe Oe Riese, Wate) Peete are et reelele pitts Sere 277 Soils GCHanpesyminmMe whos sch gett te tora slates teak lode! ofakatalotoleraratavers (oles teorstoteee as aie wise lc 542 determination of moisture in field samples, paper by Noyes and Trost................ 95 of organic matter by accurate loss-on-ignition method, paper by Rather, MELETENGE Sao oars alee ai sdatated ov aysuay= Sheen ye eas adie wiheclernels areal erere ofphosphorus, paper by, INoyes:2)s455 3 ascccacciccos ee eels noes dee eile 93 lime absorption coefficient recommendations line (Cheyne Oe Bs. 7 I Ce Oe ene SOCEM REIne Shri code 242, 564 iyi Mae brite 3, Narr ote osc casio levee duet oi basieioy mire eos earmeiet ne ee 390 LE POLED VPNTAG DRUG gee yore a cect sre eel cite, Pectin ele teken eee genes ois nr ead 389 lime requirement determination by the plant and by the chemist, paper by Hartwell, Reniberianid Et Oward 1 .cea Pen s.r ec else Sic ags ode ons Pale woo tue stele actos aoe 123 recommendations len) CCSINTTIGeU Ge Cone IG One oa” 0 PEROT