Background

Theodore William Richards, the son of William Trost and Anna (Matlack) Richards, was born in Germantown, Pennsylvania, and died in Cambridge, Massachussets Both his father, a well-known marine artist, and his mother, a writer of both prose and poetry, were intensely interested in the intellectual development of their children. While Richards was still a boy the family lived for two years in England where lifelong friendships were begun.

Education

Most of his early education was obtained at home from his mother, and because of his quick intelligence he made such rapid progress that at the age of thirteen he was prepared to enter Haverford College. The next year, however, he spent at home, where, still under the guidance of his mother, he completed the studies of the freshman year at Haverford. In the fall of 1882 he entered the sophomore class at Haverford and graduated (S. B. ) with high honors in 1885. His interest in science became evident at an early age when he independently carried on simple chemical experiments at home. Later, in Haverford College, he received a thorough grounding in chemistry under Professor Lyman B. Hall and at the same time became so much interested in astronomy that at one time he considered choosing this field for his life work. Intimate acquaintance with Prof. Josiah P. Cooke of Harvard, who was a summer neighbor at Newport, Rhode Island, probably played a large part in his final decision to follow the career of a chemist. In the fall of 1885 he entered Harvard College as a senior and devoted the whole of his time for the next three years to the study of chemistry. He received the bachelor's degree with highest honors in chemistry in 1886 and the doctor's degree in 1888. As a graduate student he came largely under the influence of Professor Cooke. At that time Cooke was particularly interested in the numerical relations of the atomic weights and, because of lack of confidence in the reliability of current values of these constants, had undertaken the revision of some of them. Cooke's high estimate of Richards' promise as an investigator led him to intrust to him the experimental determination of the relation of the atomic weights of hydrogen and oxygen, by finding the weight of water obtained in burning a weighed amount of hydrogen with copper oxide. In this extremely exacting problem Richards showed at once the qualities which made him the foremost experimental chemist of his time. "An infinite capacity for taking pains, an uncompromising attitude toward the possibilities of hidden errors, a determination to be certain that no precaution had been overlooked, an extraordinary persistence in the patient repetition of exacting and laborious experiments were combined with unusual manual dexterity and ingenuity". The result of this investigation has stood the test of time as one of the most accurate determinations of this ratio. After completion of his graduate work Richards spent one year as a traveling fellow of Harvard University in Europe. There he studied for short periods under such masters as Jannasch, Victor Meyer, and Hempel.

Career

On his return from Europe he was appointed assistant in quantitative analysis at Harvard, to become instructor in 1891 and assistant professor in 1894. Seven years later, in 1901, he declined a call to a permanent research professorship in the University of Göttingen when Harvard promoted him to a full professorship with a reduction in the duties expected by the University.

In 1912 he was appointed to the Erving Professorship of Chemistry, a title which he held till his death. The interest which Richards always showed in measurements of precision was founded upon the deep-rooted belief, now universally held that only through a precise knowledge of the properties of matter was progress in chemical science to be made.

As an independent investigator he naturally followed the lines on which he had begun. At that time he was inclined to believe that some concealed relationship existed between the properties of the elements and the atomic weights and therefore undertook the revision of some of these constants. Even as late as 1910 he writes: "But some may contend that the very exact determination of these quantities is after all an abstract and academic question, not of great practical significance.

When mankind discovers the fundamental laws underlying any set of phenomena, these phenomena come in much larger measure than before under his control and are applicable for his service. Until we understand the laws, all depends upon chance. Hence, merely from the practical point of view of the progress of humanity, the exact understanding of the laws of nature is one of the most important of all the problems presented to man; and the unknown laws underlying the nature of the elements are obviously among the most fundamental of these laws of nature. In brief, that is the reason why more than twenty years ago the systematic study of the atomic weights was begun at Harvard University by the author".

Beginning with copper he redetermined with his own hands the atomic weights of barium, strontium, and zinc and later largely with the aid of graduate students as laboratory assistants, he investigated twenty additional elements.

While in the course of this work many new analytical processes were devised and perfected, he was early forced to the conclusion realized by Marignac, Dumas, and Stas that the comparison of the chlorides and bromides of the elements with silver and the silver halides provides an analytical operation capable of greater precision than any other. He brought the experimental details of this comparison to a far higher degree of perfection than it had previously reached so that it has been possible for others to follow in his footsteps with comparatively little effort. In all this work especial attention was paid to methods of purification and to the possibility of variability in the composition of an element, long before the suspicion of isotopy arose.

He recognized the difficulty of freeing any substance from traces of moisture and devised the "bottling apparatus" for protecting a substance once dried from contact with moisture before it could be weighed. The procedure which he found necessary for determining the end point in the comparison of halides with silver by means of "nephelometer" has suffered little or no modification in the course of years, while his investigations on the contamination of precipitates through occlusion have been largely the basis of modern work on the subject. These determinations of the atomic weights brought to light many inaccuracies in older work, not excepting the classical work of Stas, who was shown, first in the case of chlorine, later in many other instances, to have been appreciably in error. Up to the present time (1934) Richards' redeterminations of the atomic weights have stood practically unchallenged.

Although Richards was best known for his revisions of the atomic weights, during the last half of his scientific career this subject assumed a subordinate part in his work. His interest in physical chemistry, already keen, was considerably stimulated by a period spent in study in Germany under Ostwald and Nernst in 1895, and for twenty-five years before his death a large part of his interest and effort was directed in various fields of physical chemistry. Thermochemistry and thermodynamics in particular engaged his attention.

His first published paper concerned the constant heat of precipitation of silver chloride. Later he devoted much energy to the perfecting of thermochemical measurements and devised the "adiabatic calorimeter" in order to avoid the troublesome and uncertain corrections due to gain or loss of heat of the calorimeter from its surroundings and to lag of the thermometer. An automatic design of this calorimeter was ultimately devised. New and highly accurate data were obtained in this way, covering heats of solution of metals in acids, heats of combustion of organic substances, heats of neutralization, specific heats of liquids, specific heats of solids at low temperatures, and heats of evaporation of liquids.

The study of the data thus obtained led him to the discovery that the magnitude of the difference between "total energy change" and "free energy change" depends upon change in heat capacity of a system during chemical change and that this difference gradually disappears as the absolute zero is approached. The discovery antedated Nernst's third law of thermodynamics.

Richards' work in thermochemistry led him into the field of thermometry and to the exact determination for the first time of the inversion temperatures of hydrated compounds for use as fixed points. As a check upon the determination of the atomic weight of copper by ordinary methods, Richards undertook the comparison of the silver and copper coulometers. The vagaries of these were investigated intimately and after due corrections had been made, Faraday's Law was found to hold within the limits of modern experimental accuracy.

This conclusion was later substantiated in the case of silver by comparisons between the deposits formed from aqueous solutions and from solutions in fused salts. Another field of electrochemistry was attacked by the determination of various single potential differences of metals and the electromotive forces between amalgams of different concentration. The latter data showed beyond question that amalgams could not be considered, except at low concentrations, to behave like ideal solutions. Richards' chief interest during the latter part of his life lay in the consideration of the relation between the physical properties of the various elements, and their compounds, especially those connected with atomic volumes and compressibilities.

He devised new forms of apparatus for determining exactly the compressibilities of the elements and their compounds, as well as certain related properties such as surface tension and heat of evaporation. This work led to the discovery of the periodicity of atomic volume and compressibility and the close parallelism between these properties, as well as to the fact that increase or decrease in volume during a chemical change depends on the one hand upon the compressibilities of the substances involved and on the other upon their chemical affinities.

The improbability that an element possesses constant atomic volume in different states of chemical combination was another conclusion drawn from this work as well as very definite and interesting ideas as to the effect of chemical affinity and cohesion upon the configuration of an atom and their relation to such properties as surface tension, vapor pressure, and heat of evaporation.

The latest aspect of this work was the attempt to compute from compressibilities and other data the actual internal pressures which hold matter together. He believed this to be the resultant of the compression due to external pressure and intrinsic compressing effects, and the distension due to thermal pressure and intrinsic distending pressure. The cohesive pressures of certain elements calculated by him are in accord with the known physical properties of these substances. In all, Richards published nearly three hundred papers covering a far wider field than that indicated in the foregoing paragraphs.

While many of the theoretical results which he reached have been and will be of the greatest importance, his contribution to the technique of precise physico-chemical investigation will undoubtedly always stand out as being equally important. Indeed he may well be said to have inaugurated a new era in the accuracy of analytical and physico-chemical experimentation.

He combined with an uncanny ability to divine previously unsuspected sources of inaccuracy, a determination to leave nothing undone in his effort to eliminate every source of uncertainty. In particular he felt strongly the necessity of making certain that the materials with which he was working conformed in quality to the precision with which the experiments were to be made, and he deplored the unfortunate fact that so much of the earlier precision measurements in chemistry had been made with material of unknown or doubtful purity or definiteness. There can be no question that his attitude has had a profound and salutary effect upon modern precise research.

He taught practically without a break from 1889 until almost the moment of his death. At first he gave instruction only in quantitative analysis but in 1896 he gave for the first time the course in physical chemistry for advanced students, with which he never severed his connection. During the same period he taught elementary physical chemistry from a historical standpoint to undergraduates.

In 1907 he was exchange professor from Harvard University to the University of Berlin. He was greatly interested in the work of his research students. His daily visits to each in the laboratory never failed to bring encouragement and to stimulate enthusiasm. The prodigious amount of experimental research of the first quality accomplished by these students bears tribute to his ability to stir up in his associates the same qualities which he possessed himself to such a high degree.

In 1925 an endowed professorship was established in Harvard University by Thomas W. Lamont, in memory of his brother Hammond Lamont, to be called the Theodore William Richards professorship of chemistry.

Achievements

• Honors came to him in rapid succession. The Davy, Faraday, and Gibbs medals were awarded in 1910, 1911, and 1912 respectively. He received the Nobel prize of 1914 for his work on atomic weights. The Franklin medal followed in 1916 and the LeBlanc and Lavoisier medals in 1922 and 1923. In 1925 he was made an officer of the French Legion of Honor. He received numerous honorary degrees.

Works

More photos

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  • The Electromotive Force of Iron Under Varying Conditions: And the Effect of Occluded Hydrogen

    (This book was originally published prior to 1923, and rep...)

  • Energy Changes Involved in the Dilution of Zinc and Cadmium Amalgams

    (This book was originally published prior to 1923, and rep...)

  • The electromotive force of iron under varying conditions, and the effect of occluded hydrogen

    (Leopold Classic Library is delighted to publish this clas...)

  • Carnegie Institution of Washington Publication No. 7. New Method for Determining Compressibility

    (Leopold is delighted to publish this classic book as part...)

  • Electrochemical Investigation of Liquid Amalgams of Thallium, Indium, Tin, Zinc, Cadmium, Lead

    (This is a pre-1923 historical reproduction that was curat...)

  • Electrochemical Investigation of Liquid Amalgams

    (This is a pre-1923 historical reproduction that was curat...)

  • Carnegie Institution of Washington publication

    (This is a pre-1923 historical reproduction that was curat...)

Membership

He was chosen a member of the American Academy of Arts and Sciences in 1891 and of the National Academy of Sciences in 1899.

He held office in many American scientific societies and was an honorary member of the most important European societies and academies.

Personality

The health and welfare of his wife and children were always in his thoughts. At the same time his wife's sympathetic appreciation of his aims and ideals was a constant source of encouragement, and the promise of his children a great satisfaction. He never failed to give the University his best efforts as a teacher and administrator, even after official release from routine had largely freed him from responsibility.

Interests

• His personality was delightful, and his interests were very wide, especially in literature, art, and music. As a boy he received a very considerable training from his father in sketching and painting and he never lost the capacity to transfer his impressions to paper with brush and pencil. Always fond of the out-doors, he enjoyed in his early years yachting and tennis, but later these were replaced by golf and motoring.

Connections

Richards was married on May 28, 1896, to Miriam Stuart Thayer, daughter of Prof. Joseph Henry Thayer, of the Harvard Divinity School. Three children survived him, a daughter and two sons.

Father:

William Trost Richards

Mother:

Anna (Matlack) Richards

Spouse:

Miriam Stuart Thayer