Osborne, Thomas Burr
OSBORNE, THOMAS BURR
(b. New Haven, Connecticut, 5 August 1859; d. New Haven, 29 January 1929)
protein chemistry.
Osborne was the son of Arthur Dimon Osborne, who was educated in law but subsequently became the president of a local bank, and Frances Louisa Blake. His ancestors on both sides can be traced in the history of New Haven to its earliest years. Osborne prepared for college at the Hopkins Grammar School in New Haven and was graduated from Yale in 1881. A year was spent in the study of medicine before he entered the Yale graduate school, where he studied chemistry under W. G. Mixter. His doctoral dissertation (1885) described the analytical determination of niobium in columbite, the mineral occurring in Connecticut in which niobium (originally named columbium) had been discovered in 1801 by Charles Hatchett. In 1886, at the invitation of Samuel W. Johnson, director of the recently established Connecticut Agricultural Experiment Station and professor of agricultural chemistry of the Sheffield Scientific School of Yale University, Osborne joined the staff of the experiment station as an analytical chemist. In the same year he married Elizabeth Anna Johnson, his director’s daughter.
While a graduate student at Yale, and during a year spent as an instructor, Osborne published several papers on analytical methods. At the experiment station he developed what became known as the Osborne beaker method for the mechanical analysis of soils, a method still in use. In 1889, owing to the passage of the Hatch Act of 1887, which provided for additional funds, Osborne began the investigations of the proteins of plant seeds, which became his lifelong work. The initial suggestion to begin this research was made by Johnson, impressed with the related work of Heinrich Ritthausen in Germany.
Johnson’s former teacher at Yale, J. P. Norton, had studied the proteins of the oat kernel some forty years earlier, and Johnson, noting that Ritthausen had not investigated this seed, suggested that further work was desirable, Although in later years Osborne stated that no seed that he subsequently worked with ever presented such difficulties as had the oat kernel, he succeeded in preparing what appeared to be a homogeneous alcohol-soluble protein and also a globulin that was obtained in crystalline form.
This success led to broadly planned research into the proteins of seeds used as human or animal food. Within two years he had obtained crystalline globulins from six different seeds, and from 1889 to 1901 he examined no less than thirty-two species, including a number of legumes, many common nuts, and the most important cereal grains. His skillful use of saline solvents, his control of acidity by the intelligent use of indicators long before the theory of pH had been developed, the use of temperature gradients, dialysis, and in certain instances of alcohol to precipitate the components of the extracts, demonstrate an instinctive appreciation of the physicochemical properties of proteins, which was many years in advance of theoretical explanation of these matters. He established what since have become the classical methods for the isolation of proteins from plant seeds.
Osborne was somewhat restricted during this early period of research by two considerations. Liebig’s dictum of fifty years earlier that there are only four kinds of protein in nature (albumin, casein, fibrin, and gelatin), although shown to be greatly oversimplified by Ritthausen and others, was still a dominating principle. Second, the motive for many studies was to show that identical proteins could be prepared from analogous tissues of different species. Inasmuch as the main criterion for the differentiation of preparations from different species was the comparison of the content of carbon, hydrogen, nitrogen, and sulfur, it can be understood how Osborne was at first frequently misled into believing that he had obtained the same protein from two or more different seeds. Thus, in 1894, he stated that, since their ultimate composition was essentially the same, the globulins of hempseed, castor bean, squashseed, flax, wheat, maize, and cottonseed are identical. For this widely distributed protein he suggested the name edestin (from the Greek for “edible”), a name later applied only to the globulin of hempseed.
Several other instances of apparent identity between pairs or small groups of proteins of different origin were later encountered. Nevertheless, as his experience broadened, Osborne became increasingly suspicious of the validity of such conclusions, and, at the turn of the century, he began to subject his extensive collection of proteins to detailed chemical study. He examined such properties as the solubility in saline solution, coagulation temperature, specific rotation, heat of combustion, color tests, the behavior of sulfur when the protein was heated with alkali in the presence of lead, and the quantitative behavior of protein toward acid and alkali, in which he sought for differences between proteins that seemed to be identical. Osborne’s closest attention, however, was given to the determination of the different forms of nitrogen in the products of complete acid hydrolysis of the proteins and to the determination of the basic amino acids by the recently published method of Kossel and Kutcher. Glutamic and aspartic acids were also determined by direct isolation.
Osborne soon came to the conclusion that the detection of differences was the fundamental problem. To obtain more complete characterizations, for about five years beginning in 1906, he devoted the full resources of his laboratory to the determination of the amino acid composition of many of the most important proteins. He used the ester distillation method of Emil Fischer for these determinations. The outcome of this labor was that, with only a few exceptions, proteins that closely resembled each other in ultimate composition could be distinguished from each other in terms of amino acid composition. When the highly sensitive biologic test dependent upon the anaphylaxis reaction became available, Osborne, from 1911 to 1916, collaborated with H. Gideon Wells of the University of Chicago in a comprehensive study of the seed proteins. Their studies showed that only two or three doubtful instances remained where proteins of different origin could not be distinguished from each other. This demonstration of the specificity of vegetable proteins with respect to source remains one of Osborne’s fundamental contributions to protein chemistry.
In 1909, Osborne invited Lafayette B. Mendel of Yale to join him in a study of the nutritive properties of the seed proteins. It was widely believed that, with a few exceptions, all proteins are alike in nutritive effect. The striking differences in the amino acid composition that had been found for a number of common food proteins raised the question of the validity of this view. The collaboration with Mendel continued from 1909 until Osborne’s retirement in 1928. They developed a technique for feeding rats that enabled them to measure the food intake, and within a few years obtained convincing proof that the amino acids tryptophan and lysine are essential in the diet. Although it was clear that the rat can synthesize some of the amino acids, this capacity is strictly limited. The study of the effect of lysine was especially rewarding since it showed that the growth of a young rat could be quantitatively controlled by the supply of lysine, either as such or combined in the protein of the diet. Animals stunted by low levels of lysine intake could be induced to grow at any age by increasing the supply.
The outstanding accomplishment of the first few years of this collaboration was the discovery of what became known as vitamin A. This discovery resulted from the comparison of the growth of rats on diets consisting of purified components, of which one contained dried whole milk and the other only the lactose and inorganic salts of milk. The substitution of butter for some of the lard in the second diet prevented the loss of weight and eventual death of the animals. This observation was made early in 1913. The conclusion was obvious that butter contains a trace amount of some fat-soluble organic substance that is essential in nutrition. Unfortunately the submission to a journal of a similar observation by E. V. McCollum of the University of Wisconsin preceded by three weeks the receipt of the Osborne and Mendel paper, and McCollum is accordingly regarded as the discoverer of the first vitamin to be recognized. Although Osborne and Mendel devoted considerable study to the natural distribution of the fat-soluble vitamin (notably finding that cod liver oil is a rich source) and the later-discovered water-soluble vitamin, their main interest during the extremely active period from 1911 to 1924 was in the phenomena of growth and in the nutritive properties of various proteins. They studied the effects of high-protein diets, low-carbohydrate and low-fat diets, and variations in the supply of inorganic salts. They obtained rational explanations for many empirical practices in animal feeding that had been found advantageous, and they cleared up the relation between nutritional ophthalmia and vitamin A. They also contributed to the demonstration of the nutritional origin of rickets; the common use of cod liver oil and orange juice in the diets of children stems largely from their work.
Although the main interest of the laboratory continued to be in nutrition, Osborne, with the aid of his assistants, also devoted much effort to the many purely chemical problems that arose. In 1919 he and Alfred J. Wakeman prepared the first vitamin-rich concentrate from an extract of brewer’s yeast. The concentrate was used for many years in the laboratory and was marketed successfully by a former assistant, Isaac F. Harris, who had become a manufacturing chemist. The observation that the alfalfa plant is rich in vitamins led to attempts to prepare the proteins from green leaves. Only moderate success attended these efforts, but A. C. Chibnall of the Imperial College, London, who joined Osborne’s group in 1923 and 1924, was later successful. In his last years Osborne also stimulated the investigations by his assistants of the simpler nitrogenous substances present in plants, a field of study that had been neglected since the early work of Ernst Schulze in Switzerland in the last decades of the nineteenth century.
Unlike his collaborator Mendel, Osborne did not have a large group of loyal and devoted students to keep his memory alive. To those who worked with him he was a rare stimulus, a formidable opponent in argument, and an ever genial but just critic. His major, in fact almost his only, interest was in the work of the laboratory. He served for many years as a director of the local bank of which his father had been president, but this and the group of close friends at his club, together with his interest in the birds of Connecticut, upon which he was an authority, provided the major relief from his daily work at the laboratory bench.
BIBLIOGRAPHY
I. Original Works. Osborne’s bibliography published in Vickery’s memoir (see below) lists titles of 252 papers that appeared in various chemical journals between 1884 and 1929. A nearly complete bound collection of his work is in the Osborne Library at the Connecticut Agricultural Experiment Station in New Haven. The papers on the preparation of proteins appeared in the American Chemical Journal or Journal of the American Chemical Society until 1904; nearly all were reprinted in the annual Report of the Connecticut Agricultural Experiment Station.
Most of the papers from 1891 to 1897 were translated into German by V. Griessmayer in Die Proteide der Getreidarten Hütsenfriüchte und Ölsamen sowie einiger Steinfruchte (Heidelberg, 1897). Griessmayer continued to translate and publich most of Osborne’s papers, which appeared up to 1908, in Zeitschrift für das landwirtschaftliche Versuchswesen in Österreich or, after 1904, in Zeitschrift für analytische Chemie.
From 1904 to 1910 Osborne’s papers were published in the American Journal of Physiology; subsequent papers appeared in the Journal of Biological Chemistry, to which Osborne and Mendel contributed most of their collaborative papers on nutrition between 1912 and 1927. Including annual reports to the Carnegie Institution of Washington there were 111 of these. The six papers on the anaphylaxis reactions of the seed proteins, written with H. Gideon Wells, appeared in the Journal of Infectious Diseases between 1911 and 1916.
Osborne’s works also include The Proteins of the Wheat Kernel, Carnegie Institution of Washington Publication no. 84 (Washington, D.C., 1907); The Vegetable Proteins, in R. H. Plimmer and F. G, Hopkins, eds., Monographs on Biochemistry (London, 1909; 2nd ed., rev., 1924); and Feeding Experiments with Isolated Food-Substances, Parts I and II, Carnegie Institution of Washington Publication no. 156 (Washington, D.C., 1911), written with Mendel.
II. Secondary Literature. Hubert Bradford Vickery has written three articles on Osborne: “Thomas Burr Osborne, 1859–1929,“ in Biographical Memoirs. National Academy of Sciences,14 (1931), 261–304; “Thomas B. Osborne, a Memorial,” in Bulletin. Connecticut Agricultural Experiment Station,312 (1930); and “Thomas Burr Osborne,” in Journal of Nutrition,59 (1956), 1–26.
The bulletin published by the experiment station contains several obituary notices, the records of the presentation of an honorary degree by Yale University in 1910, the presentation of the John Scott Medal by the board of directors of City Trusts of Philadelphia in 1922, and the presentation of the Thomas Burr Osborne Medal by the American Association of Cereal Chemists in 1928. It also contains reprints of Osborne’s addresses on protein chemistry to several organizations, a previously unpublished paper on bird migration, and a complete bibliography of his papers.
Hubert Bradford Vickery