Wilke, Carl:  Vitamin A Has Been Synthesized by Kuhn , Indust. & Engin. Chem. , News. Ed. 29:291 (
(July 10)
) 1937;.
League of Nations, Health Organisation: Second Conference on Vitamin Standardisation, London, June 12-14, 1934
Quart. Bull. Health Organ., League of Nations 3:428 (
(Sept.)
) 1934;.
United States Pharmacopeial Convention: The Pharmacopeia of the United States of America , Eleventh Decennial Revision, 1935;.
Drummond, J. C., and Coward, Katharine H.:  Researches on the Fat-Soluble Accessory Factor (Vitamin A): VI. Effect of Heat and Oxygen on the Nutritive Value of Butter , Biochem. J. 14:734 (no.
(6)
) 1920;.
Osborne, T. B., and Mendel, L. B.:  Nutritive Factors in Plant Tissues: IV. Fat-Soluble Vitamine , J. Biol. Chem. 41:549 (
(April)
) 1920;.
Coward, Katharine H.; Key, Kathleen M.; Dyer, F. J., and Morgan, Barbara G. E.: Â The Determination of Vitamin AÂ , Biochem. J. 24:1952 (no.
(6)
) 1930;.
Coward, Katharine H.:  The Relation of the Growth Response to Dosage of Vitamin A: Confirmation of a Curve Relating Response to Dose of Vitamin A Given , Biochem. J. 28:865 (no.
(3)
) 1934;.
Todhunter, E. N.: Â A Comparison of Heated Casein with Extracted Casein in the Basal Diet for the Determination of Vitamin AÂ , J. Nutrition 13:469 (
(May)
) 1937;.
Evans, H. M., and Lepkovsky, Samuel:  Vital Need of the Body for Certain Unsaturated Fatty Acids: III. Inability of the Rat Organism to Synthesize the Essential Unsaturated Fatty Acids , J. Biol. Chem. 99:231 (
(Dec.)
) 1932;.
Nelson, E. M.:  Regulating the Storage of Vitamin A in Animals That Are to Be Used for the Determination of This Vitamin , Science 68:212 (
(Aug. 31)
) 1928;.
Unpublished data, United States Department of Agriculture, Bureau of Home Economics.
Nelson.8 U. S. Pharmacopeia.3
Sherman, H. C., and Burtis, M. P.: Â Factors Affecting the Accuracy of the Quantitative Determination of Vitamin AÂ , J. Biol. Chem. 78:671 (
(Aug.)
) 1928;.
Norris and Church.43 U. S. Pharmacopoeia.3
Irwin, Margaret H.; Brandt, A. E., and Nelson, P. Mabel:  Applications of Statistical Method to the Data of Vitamin Feeding Experiments: I. The per Cent Effect of Measured Variables , J. Biol. Chem. 88:449 (
(Sept.)
) 1930;
Coward, Katharine H.; Dyer, F. J.; Morton, R. A., and Gaddum, J. H.:  The Determination of Vitamin A in Cod Liver Oils (a) Biologically, (b) Chemically, (c) Physically, with a Statistical Examination of the Results , Biochem. J. 25:1102 (no.
(4)
) 1931;.
Sherman, H. C., and Batchelder, E. L.:  Further Investigation of Quantitative Measurement of Vitamin A Values , J. Biol. Chem. 91:505 (
(May)
) 1931;.
Coward, Katharine H.:  The Influence of the Length of the Test Period on the Accuracy Obtainable in a Vitamin A Test , Biochem. J. 27:445 (no.
(2)
) 1933;.
Coward, Katharine H.:  Variation in Growth Response of Rats in Vitamin A Tests Compared with the Variation in Rats Growing Normally , Biochem. J. 26:691 (no.
(3)
) 1932;.
Coward, Katharine H., and Key, Kathleen M.:  Simplification of Vitamin Tests: The Effect of Giving Doses Half-Weekly for Vitamin A Tests, and Once Only for Vitamin D Tests, Instead of Giving Doses Daily , Biochem. J. 28:870 (no.
(3)
) 1934;.
Sherman, H. C., and Munsell, Hazel E.: Â The Quantitative Determination of Vitamin AÂ , J. Am. Chem. Soc. 47:1639 (
(June)
) 1925;.
E. V. McCollum ( The Fat-Soluble Vitamins , in Luck, J. M.: Annual Review of Biochemistry , Stanford University, Calif., Stanford University Press, 1936;, p. 379).
 The Permanent Commission on Biological Standardisation of the Health Organisation of the League of Nations at its 1931 conference (Report of the Conference on Vitamin Standards, London, June 17-20, 1931, Geneva , 1931;, p. 68)
Daniel, Esther P., and Munsell, Hazel E.: Vitamin Content of Foods: A Summary of the Chemistry of Vitamins, Units of Measurement, Quantitative Aspects in Human Nutrition, and Occurrence in Foods , Misc. Pub. 275, United States Department of Agriculture, Bureau of Home Economics, 1937;.
Unpublished data, Bureau of Home Economics, United States Department of Agriculture.
Sherman, H. C., and Cammack, M. L.: Â A Quantitative Study of the Storage of Vitamin AÂ , J. Biol. Chem. 68:69 (
(April)
) 1926;.
Nelson, E. M.; Walker, Reed, and Jones, D. B.:  Determination of Vitamin A by a Preventative Method , J. Biol. Chem. 92:vi (
(June)
) 1931;.
Sherman, H. C., and Todhunter, E. N.:  The Determination of Vitamin A Values by a Method of Single Feedings , J. Nutrition 8:347 (
(Sept.)
) 1934;.
Hodgson, R. E., and Knott, J. C.:  The Method of Single Feeding as Used in Measuring the Vitamin A Activity of Pasture Grass Artificially Dehydrated at Different Temperatures , Am. Dairy Sc. A. West. Div. 22d Annual Meeting Proc., 1936 , p. 41.
Evans, H. M., and Bishop, K. S.:  On the Existence of a Hitherto Unrecognized Dietary Factor Essential for Reproduction , Science 56:650 (
(Dec. 8)
) 1922;.
Macy, Icie G.; Outhouse, Julia; Long, M. Louisa, and Graham, Alice:  Human Milk Studies: I. Technique Employed in Vitamin Studies , J. Biol. Chem. 73:153 (
(May)
) 1927;.
Coward, Katharine H.:  The Influence of Vitamin A Deficiency on the Oestrous Cycle of the Rat , J. Physiol. 67:26 (
(Feb. 28)
) 1929;.
Coward, Katharine H.; Morgan, Barbara G. E., and Dyer, F. J.: II.,  The Influence of Vitamin A Deficiency on the Oestrous Cycle of the Rat J. Physiol. 69:349 (
(May)
) 1930;.
Baumann, C. A., and Steenbock, Harry: Â The Vaginal Smear Method of Determining Vitamin AÂ , Science 76:417 (
(Nov. 4)
) 1932;.
Rosenheim, Otto, and Drummond, J. C.:  On the Relation of the Lipochrome Pigments to the Fat-Soluble Accessory Food Factor , Lancet 1:862 (
(April 17)
) 1920;.
Rosenheim, Otto, and Drummond, J. C.: Â A Delicate Colour Reaction for the Presence of Vitamin AÂ , Biochem. J. 19:753 (no.
(4)
) 1925;.
Carr, T. H., and Price, E. A.: Â Colour Reactions Attributed to Vitamin AÂ , Biochem. J. 20:497 (no.
(3)
) 1926;.
 Antimony Trichloride Test for Cod Liver Oil , British Pharmacopeia , 1932;, p. 596.
Wokes, F., and Willimott, S. G.: Â A Study of Antimony Trichloride as a Possible Quantitative Reagent for Vitamin AÂ , Analyst 52:515, 1927;.
Norris, E. R., and Danielson, I. S.:  Comparison of Biological and Colorimetric Assays for Vitamin A as Applied to Fish Oils , J. Biol. Chem. 83:469 (
(Aug.)
) 1929;.
Norris, E. R., and Church, A. E.:  A Study of the Antimony Trichloride Color Reaction for Vitamin A: II. The Dilution Curve of Cod Liver Oil with Antimony Trichloride Reagent , J. Biol. Chem. 87:139 (
(May)
) 1930;.
Norris, E. R., and Church, A. E.:  A Study of the Antimony Trichloride Color Reaction for Vitamin A: I. J. Biol. Chem. 85:477 (
(Jan.)
) 1930;.
Smith, E. L., and Hazley, Violet:  The Reaction of Antimony Trichloride with Cod Liver Oil and Its Unsaponifiable Fraction , Biochem. J. 24:1942 (no.
(6)
) 1930;.
Wise, E. C., and Heyl, F. W.:  Vitamin A Colorimetric and Biological Assay , J. Am. Pharm. A. 21:1142 (
(Nov.)
) 1932;.
Andersen, A., and Nightingale, E.:  Test for Vitamin A in Margarine, Butter, and Other Fatty Foods , J. Soc. Chem. Ind. 48:139T (
(June 14)
) 1929;.
Andersen, A. C., and Levine, V. E.:  Reaction to Differentiate Vitamin A from Carotene by Means of Antimony Trichloride , Proc. Soc. Exper. Biol. & Med. 32:737 (
(Feb.)
) 1935;.
Ender, Fredrik:  The Reaction of Fish-Liver Oils with Antimony Trichloride , Biochem. J. 26:1118 (no.
(4)
) 1932;.
Huston, R. C.; Lightbody, H. D., and Ball, C. D., Jr.:  Some Biochemical Relations of Phenols: II. The Effect of Hydroquinone on the Vitamin A Content of Stored Oils , J. Biol. Chem. 79:507 (
(Oct.)
) 1928;.
Rosenthal, Eugene, and Erdelyi, John: Â Some Remarks Concerning the New Colour Reaction of Vitamin AÂ , Biochem. J. 29:2112 (
(Sept.)
) 1935;.
Corbet, Ruth E.; Geisinger, Helen H., and Holmes, H. N.: Â Substances Which Interfere with the Antimony Trichloride Test for Vitamin AÂ , J. Biol. Chem. 100:657 (
(May)
) 1933;.
Norris, E. R., and Church, A. E.: Â A Study of the Antimony Trichloride Color Reaction for Vitamin A: V. Evaluation of a Colorimetric Unit on the Basis of the Biological Unit for Vitamin AÂ , J. Nutrition 5:495 (
(Sept.)
) 1932;.
Carr, F. H., and Jewell, William: Â Characteristics of Highly Active Vitamin AÂ , Nature 131:92 (
(Jan. 21)
) 1933;.
Lathbury, Kathleen C.:  Vitamin A Determination: Relation Between the Biological, Chemical and Physical Methods of Test , Biochem. J. 28:2254 (no.
(6)
) 1934;.
Holmes, N. H., and Corbet, Ruth E.:  A Crystalline Vitamin A Concentrate , Science 85:103 (
(Jan. 22)
) 1937;.
Drummond, J. C., and Morton, R. A.: Â Observations on the Assay of Vitamin AÂ , Biochem. J. 23:785 (no.
(4)
) 1929;.
Coward, Katharine H.; Dyer, F. J., and Morton, R. A.:  The Determination of Vitamin A in Cod Liver Oils, (a) Biologically, (b) Chemically, (c) Physically, with a Statistical Examination of the Results: II. Further Evidence That the Intensity of Absorption at 328 Millimicrons Gives the Best Agreement with the Biological Measure of Vitamin A in Cod Liver Oils , Biochem. J. 26:1593 (no.
(5)
) 1932;.
Morton, R. A.; Heilbron, I. M., and Thompson, Albert:  Spectrographic Data Concerning Vitamin A and Liver Oils , Biochem. J. 25:20 (no.
(1)
) 1931;.
Heilbron, I. M.; Heslop, R. N.; Morton, R. A.; Webster, E. T.; Rea, J. L., and Drummond, J. C.;  Characteristics of Highly Active Vitamin A Preparations , Biochem. J. 26:1178 (no.
(4)
) 1932;.
Gillam, A. E., and Morton, R. A..  The Antimony Trichloride Colour Test and the Ultraviolet Absorption of Liver Oils and Concentrates , Biochem. J. 25:1346 (no.
(4)
) 1931;.
Heilbron, I. M.; Gillam, A. E., and Morton,R. A.:  Specificity in Tests for Vitamin A: A New Conception of the Chromogenic Constituents of Fresh and Aged Liver Oils , Biochem. J. 25:1352 (no.
(4)
) 1931;.
Brode, W. R., and Magill, Mary A.: Â A Critical Study of the Antimony Trichloride Color Test for Vitamin AÂ , J. Biol. Chem. 92:87 (
(June)
) 1931;.
Magill, Mary A., and Brode, W. R.:  A Comparison Between the Spectrophotometric and Biological Assay for the Vitamin A Content of Fish Liver Oils , Ohio J. Science 33:127 (
(March)
) 1933;.
Morton, R. A.: Â The use of 7-Methylindole in the Antimony Trichloride Colour Test for Vitamin AÂ , Biochem. J. 26:1197 (no.
(4)
) 1932;.
Takahashi, K.; Nakamiya, Z.; Kawakami, K., and Kitasato, T.:  On the Physical and Chemical Properties of Biosterin (a Name Given to Fat-Soluble A) and on Its Physiological Significance , Inst. Phys. Chem. Res. (Tokyo) Sc. Papers 3:81 (no.
(32)
) 1925;.
Morton, R. A., and Heilbron, I. M.: Â The Absorption Spectrum of Vitamin AÂ , Biochem. J. 22:987 (no.
(4)
) 1928;.
Macwalter, R. J.:  Some Factors Which Affect the Assay of Vitamin A by the Spectrographic Method , Biochem. J. 28:472 (no.
(2)
) 1934;.
Crews, S. K., and Cox, S. J.: Â The Relationship between the CarrPrice Value and the 328 Millimicron Absorption Coefficient of Preparations Containing Vitamin AÂ , Analyst 59:85 (
(Feb.)
) 1934;.
Morgan, R. S.; Edisbury, J. R., and Morton, R. S.:  A Discrepancy Between Biological Assays and Other Methods of Determining Vitamin A: I. Biochem. J. 29:1645 (
(July)
) 1935;.
Pritchard, Harry; Wilkinson, Harry; Edisbury, J. R., and Morton, R. A.: II.  A Discrepancy Between Biological Assays and Other Methods of Determining Vitamin A: I. Biochem. J. 31:258 (
(Feb.)
) 1937;.
Hume, E. Margaret, and Chick, Harriette: Reports on Biological Standards: IV. The Standardisation and Estimation of Vitamin A, Medical Research Council, Special Report Series, no. 202, London, His Majesty's Stat. Off., 1935.
Hume, E. M.: Â Estimation of Vitamin AÂ , Nature 139:467 (
(March 13)
) 1937;.
Emmett, A. D., and Bird, O. D.:  Comparative Biological Value of Vitamin A as an Alcohol and Ester , J. Biol. Chem. 119:xxxi (
(June)
) 1937;.
Wilkie, J. B.:  Report on Vitamin A: Determinations with the Hilger Vitameter , J. A. Off. Agric. Chem. 20:208 (
(May)
) 1937;.
Morton, R. A., and Heilbron, I. M.:  Vitamin A of Butter , Biochem. J. 24:870 (no.
(4)
) 1930;.
Gillam, A. E.; Heilbron, I. M.; Morton, R. A.; Bishop, Gerald, and Drummond, J. C.:  Variations in the Quality of Butter, Particularly in Relation to the Vitamin A, Carotene, and Xanthophyll Content as Influenced by Feeding Artificially Dried Grass to Stall-Fed Cattle , Biochem. J. 27:878 (no.
(3)
) 1933;.
Gillam, A. E.; Heilbron, I. M.; Ferguson, W. S., and Watson, S. J.:  Variations in the Carotene and Vitamin A Values of the Milk Fat (Butter) of Cattle of Typical English Breeds , Biochem. J. 30:1728 (
(Sept.)
) 1936;.
Irish, F. W.:  Report on Vitamin A: Determinations with the Hilger Vitameter , J. A. Off. Agric. Chem. 19:244 (
(May)
) 1936;.
McFarlan, R. L.; Reddie, J. W., and Merrill, E. C.: Â A New Photoelectric Method for Measuring Vitamin AÂ , Indust. & Engin. Chem. 29:324 (
(July 15)
) 1937;.
Fraps, G. S.; Copeland, O. C., and Treichler, R.: The Vitamin A Requirements of Dairy Cows , Bull. 495, Texas Agricultural Experiment Station, 1934;.
Sherwood, R. M., and Fraps, G. S.: The Amount of Vitamin A Potency Required by Hens for Egg Production , Bull. 493, Texas Agricultural Experiment Station, 1934;.
Watson, S. J.; Bishop, Gerald, and Drummond, J. C.:  The Relation of the Colour and Vitamin A Content of Butter to the Nature of the Ration Fed: I. Influence of the Ration on the Yellow Colour of the Butter , Biochem. J. 28:1076 (no.
(3)
) 1934;.
Wilbur, J. W.; Hilton, J. H., and Hauge, S. M.:  The Vitamin A Activity of Butter Produced by Guernsey and Ayrshire Cows , J. Dairy Sc. 16:153, 1933;.
Moore, Thomas:  Vitamin A and Carotene: IX. Notes on the Conversion of Carotene to Vitamin A in the Cow , Biochem. J. 26:1 (no.
(1)
) 1932;.
Booth, R. G.; Kon, S. K., and Gillam, A. E.:  The Relative Biological Efficiencies of the Vitamin A and Carotene of Butter , Biochem. J. 28:2169 (no.
(6)
) 1934;.
Sherman, H. C.: Chemistry of Food and Nutrition , ed. 5, New York, The MacMillan Company, p. 366.