data on the mechanical analyses of the soils as given by the Soil Survey. It will be noted that the soil with a high clay content will pull up a mercury column close to 40 cm which, in terms of a water column, is equal close to 18 feet. The significance of this will be brought out more clearly when we shall presently speak of certain irrigation projects based on the suction force. Several other applications of the suction force principle may be suggested. It is known that the roots of the plant imbibe water from the soil with a certain force. Briggs and McCalls have produced an artificial root with which they attempted to measure this force. What they actually did was to measure in part the suction force of the soil. Now it is reasonable to assume that since the suction force, as described by the authors, is a property of the surface energy of the substances in immediate contact with the outside wall of the porous candle, then the force exhibited by the soil is the force which plant roots have to overcome when the soil ceases to be saturated. At saturation no force has to be exhibited by the plant roots save that of absorbing the water against gravity. As we decrease the moisture content of the soil the greater the force the plant roots have to exert in order to pull the water. The suction force of the soil as shown by Kornev reaches its critical moment when it is equal to about one half of its saturation. It then drops. This phenomenon may easily be linked together with the wilting point of plants in plant physiological researches. It will be possible to determine the wilting point in terms of the suction force. In clay soils with a relatively high moisture content, wilting appears earlier than in sandy soils with less moisture. The clay exhibits a tremendous suction force which the plant has to overcome, while in sand there is practically no suction force to oppose the pulling power of the plant. The suction force principle may therefore be applied in quantitative studies of wilting coefficients in the soil-plant system. Various soils will differ in their suction force and it is this force which undoubtedly determines the critical point of moisture content in relation to wilting. But there is another aspect of this relation. Caldwell states, and 8 Briggs, L. J., and McCall, A. G., 1904, “An artificial root for inducing capillary movement of soil moisture.'' In SCIENCE, N. S. 20, No. 13, pp. 566-569. Kornev, V. G., 1924, "The suction force of soils," In Zhurnal Opitnoi. Agron. (Russian Jour. of Exp. Agron.) 22 (Orig. papers) pp. 105-111, (1921–1923). 5 Caldwell, Joseph Stewart, 1913, "The relation of environmental conditions to the phenomenon of permanent wilting in plants." In Phys. Resear. v. 1, no. 1, pp. 1-56. 6 this is borne out by Shive and Livingston, that "under any given set of conditions, the observed soil moisture content at permanent wilting is approximately a constant for each of the soils used, and its value increases with the increase in rate of transpiration, being greater under conditions of high evaporation intensity and declining with decrease in the evaporating power of the air." In the light of the phenomenon of the suction force of soils, the above may be looked upon as follows: when the suction force of the soil is greater than the pulling power of the plant wilting must ensue. The factor or factors which influence the pulling power of the plant, such as high or low evaporation intensity, will shift the equilibrium between the suction force of the soil and the pulling power of the plant. The problem of the wilting of plants may thus be reduced to a study of the two factors: the suction force of the soil and the evaporation intensity of the air as it is linked with transpiration. The advantage of using the suction force expression lies in the fact that it is an inherent property of the physico-chemical make-up of the soil. Another possible application of the suction force of the soil is a study of the moisture movement in the soil profiles. As mentioned above the suction force of a soil is chiefly governed by the surface effects of the colloid fraction of the soil. It is natural that the movement of the water between the adjacent layers of soil should be controlled by this suction force. A study of the suction force of the various layers of the plowed or tillable soil horizon may reveal some interesting data in respect of the vantage points in the soil in respect to moisture relationships. When, for the sake of argument, the upper layer of the soil has a suction force of 25 cm and the zero point (no suction force) is at 30 per cent. moisture content, the next adjacent layer has a suction force of 30 cm and its zero point is at 35 per cent. moisture, we may expect a resultant forcing the water downward. There may be conditions whereby the movement of water will be upward. All that will have its influence on the power of plants to imbibe water, and the entire picture of the suction force of the various horizons will give us information on the movement of soil water. One of the primary objects of the study of the suction force by Kornev was for the purpose of 6 Shive, John W., and Livingston, Burton E., 1914, "The relation of atmospheric evaporating power to soil moisture content at permanent wilting in plants." In Plant World, v. 17, no. 4, pp. 81-121. 7 Kornev, V. G., 1924, “The absorbing power of soils and the principle of automatic self-irrigation of soils." In Soil Sci., v. 17, pp. 428–429. The irrigation. Only meager data are available on the subject. We may imagine that an irrigation system based on the suction force of the soil could be constructed in the following way: porous clay pipes may be placed in the soil at a certain depth and at a certain distance apart, depending on the suction force of the layer in which the pipes are placed. source of the water supply may be at a level lower than the field desired to irrigate, since the suction force as shown above will lift a column of water 10 to 15 feet or more, depending on the amount of colloids present. A reservoir may be constructed which when kept at a certain level will supply the water to the soil up to any desired moisture content. In the event of a rain the level of the reservoir may be lowered and the system will serve as a drainage system. Another use made of the principle of the suction force by the authors is the utilization of the high suction force of one soil to obtain the soil solution from a soil with a lower suction force. This has been done in the following way: two Pasteur clay candles were immersed in two different soils, respectively. The sandy soil with a low suction force was moistened previously and its candle was empty; on the other hand the candle in the dry clay soil with a high suction force was filled with water. Both candles were connected in a closed system with rubber stoppers and glass tubing. The suction force of the clay soil produced a vacuum in its candle taking out the water; this naturally evacuated the candle in the sandy soil and the soil moisture entered the candle. Thus the soil solution was obtained. In brief it meant that the suction force of the soil has been utilized in place of a vacuum pump. NEW JERSEY AGRICULTURAL EXPERIMENT STATION J. S. JOFFE AMERICAN MATHEMATICAL SOCIETY THE two hundred and forty-fourth regular meeting of the American Mathematical Society was held at Columbia University, on Saturday, October 31, 1925, extending through the usual morning and afternoon sessions. The attendance included fifty members of the society. At the meeting of the council, nine persons were elected to membership in the society, and twenty-five applications for membership were received. The following papers were read at this meeting: Definitions and postulates for relativity: H. P. MANNING. Space-time and mass: G. Y. RAINICH. Interpretations of Poisson's integral: O. D. KELLOGG. The summation of a family of series of a certain type: I. J. SCHWATT. Large primes have at least five consecutive quadratio residues: A. A. BENNETT. A note on the functional equation f(x + y) = f(x) + f(y): MARK KORMES. Some theorems on continuous curves containing no simple closed curve: H. M. GEHMAN. On irredundant sets of postulates: H. M. GEHMAN. A property which characterizes continuous curves: R. L. WILDER. A theorem on connected point sets which are connected im kleinen: R. L. WILDER. Note on the continuity of a function defined by a def nite Lebesgue integral: H. J. ETTLINGER. On the expansion of an analytic function in a series of polynomials: J. L. WALSH. On the position of the roots of entire functions of genus zero and unity: J. L. WALSH. On isolated singular points of harmonic functions: G. E. RAYNOR. On the structure of a limited continuum, irreducible between two points: W. A. WILSON. The algebraic structure of the formulas in plane trigonometry. Third paper: T. H. GRONWALL. Summation of series and conformal mapping: T. H. GRONWALL. A new form of the remainder in the binomial series, with applications: T. H. GRONWALL. Almost-periodic functions of two variables: PHILIP FRANKLIN. The elementary character of certain integrals related to figures bounded by spheres and planes: PHILIP FRANKLIN. Concerning the arcs and domains of a continuous curve: W. L. AYRES. A new method in periodogram analysis: NORBERT WIENER. The convergence of Bessel's series: M. H. STONE. THOMAS. The research manuscripts and library of Dr. Robert Adrain, professor of mathematics at Rutgers, Columbia, and Pennsylvania. Preliminary report: M. J. BABB. Note on the convergence of Fourier series: DUNHAM JACKSON. New division algebras: L. E. DICKSON. A theorem on continuous curves in space of n dimen sions: H. M. GEHMAN. The society will hold its annual meeting at Hunter College, New York City, January 1 and 2, 1926. It will also hold a meeting in affiliation with the American Association for the Advancement of Science at Kansas City, December 29 and 30, 1925; on this occasion Professor James Pierpont will deliver the third Josiah Willard Gibbs Lecture. R. G. D. RICHARDSON, Secretary CONTENTS No. 1616 John Mason Clarke: DR. CHARLES D. WALCOTT......... 558 Scientific Events: An Osler Memorial Volume; A New Wisconsin University and Educational Notes..... The Music of the American Indians: FRANCES Some New Books on Genetics: PROFESSOR W. E. 558 560 564 565 567 SOME PROBLEMS OF MEDICAL INVESTIGATION AND MEDICAL EDUCATION1 THE laying of a corner-stone is an occasion on which one's imagination as to the future is stimulated to activity and one's thoughts naturally turn toward consideration of the probable future activity of the building whose erection is to proceed. This structure, whose corner-stone we lay to-day, is to be a hospital for the clinical activities of a graduate school of medicine, and it is a memorial to perpetuate for all time a name-Albert Merritt Billings. Broadly speaking, herein lie the purposes of the structure to be erected on this corner-stone. The corner-stone itself, architecturally considered, is an entirely dispensable feature of a building and in no wise determines the character of the structure to be built in due season, following its laying. However, about a corner-stone center the ideas and sentiments which in future years will be the real expression of the purposes of the structure and constitute an undying memorial to the name honored by the donors of the building. On such an occasion it may not be inappropriate to devote a little time to the consideration of some problems of medical investigation and medical education. It is recognized very generally to-day that all great hospitals have three functions, care of the sick, investigation of disease and education of all patients, nurses, physicians and surgeons, that pass its portals. Different institutions may stress in particular some one of these functions; no hospital, worthy of the name, may neglect entirely any of this triad. A hospital is an indispensable unit in a school of medicine, be that school intended primarily for investigation or to educate practitioners or teachers and investigators. The hospital constitutes a fundamental difference between a graduate school of medicine and all other graduate schools, inasmuch as it introduces into the problem the care of sentient human beings in the guise of patients. It is an inescapable fact that the first concern of every hospital is the best possible care of its patients, whatever of the three great functions of a hospital is to be stressed by the particular 1 Address delivered at the laying of the corner-stone of the Albert Merritt Billings Hospital of the University of Chicago, at Chicago, Illinois, on October 2, 1925. institution. The hospital may select patients as it wills. Once selected, patients must be given the best service possible in a form so personal that each patient feels that the institution is serving him in particular. These facts must be taken into account in the selection of staff, from chiefs to subordinates, in the character and limitations of investigation and in the methods of education. The ideas of the function of a hospital expressed above have been a gradual growth over a long period of time, but it is only comparatively recently that they have come into general recognition. Perhaps the lay public does not yet fully recognize them, though rapidly they are adopting this conception of a hospital. With the more general recognition of these functions of a hospital has gone a progressive improvement in medical education. Many factors undoubtedly have played a part in bringing about these changes, but this is not the appropriate time to discuss them. At the same time I do wish to emphasize one factor whose very great importance it seems to me has not been sufficiently recognized by critics and prophets of medical education. I refer to the part played by the great medical men here in this country that were the leaders in medicine of the generation just preceding our own, to men like the elder Janeway in New York, Fitz and Shattuck in Boston, Osler in Baltimore and your own Billings here in Chicago, to mention but a few and only the internists of that large coterie of medical men who by example and precept were the leaders of the generation whose professional activity has but recently ceased. These men, more than any other influences, are responsible for our developments in medicine to-day. They had the vision, the courage, the perseverance and the character to do the work, without which we would not be to-day where we are. They laid the foundations on which have been builded the present-day structure of medical education and hospital organization. To them, rather than to critics of medical schools and theorists in medical pedagogy, should go our grateful thanks for present-day conditions. I often wonder, with many doubts I must confess, whether our leaders of to-day are of the caliber of these men, or merely shine by reason of the material equipment supplied by great philanthropists and foundations. As I imagine the future I picture two general types of hospitals, the one primarily concerned in the expeditious care of many patients, the other chiefly devoted to medical education and investigation. Both, it seems to me, will be quite different from what we now find developed in most, if not all, of our medical centers. In the former the ambulatory diagnostic clinic will play a larger part, for diagnostic methods, though numerous and complicated, rapidly are becoming simplified so that they may be applied to patients who make periodic visits to the hospital at appointed hours. Many more patients than now will be taken into our hospitals who already have been completely worked up and are admitted ready for appropriate therapeutic procedures. This study, preliminary to admission, as well as that on those admitted unworked up, probably will be carried out by a general diagnostic service, whether the patients' future therapy is to be medical or surgical or of other sort. Medical specialism here will have a decreasing import. Within the hospital therapeutic measures of all types will be speedily instituted, and in a relatively short time, for most patients, they will be continued in out-of-town branches somewhat of the nature of convalescent homes. Here surgical cases will spend much of the period necessary for convalescence from therapeutic methods of the surgeon, and medical patients will undergo régimes of dietary or medicinal or mechanical treatment, perhaps to be returned at intervals to the central hospital for such tests of function, etc., as can not be carried out in the convalescent branch of the institution. Easy methods of transportation make possible this arrangement. The beds of such a central hospital will be occupied by each patient for a far shorter average period than at present. Diagnostic work in large part will be done before admission, while convalescent care and observational methods of treatment will be applied in these country branches, where, with the economic advantages of a lower land cost and less expensive construction, will be combined the therapeutic advantages of fresh air, unobstructed sunlight and nearness to God's green earth. Internes and resident staff will serve in rotation in both the urban and country branches of the work. Surgery as such will be recognized as but a form of therapy, while both surgeon and physician will work in the general diagnostic clinic without regard to whether he is on surgical, medical or special service, but rather as a man skilled in some particular diagnostic method which will form part of the basis of the final diagnosis. Investigation and education too will be part of the function of such a hospital, but its efficiency will be measured largely in the terms of excellent and expeditious care of patients. I have merely outlined in general terms my idea of this type of hospital of the future. Many details, of course, will be developed differently in different places. To my mind most of our large hospitals will take on this type. Some already are being developed along these lines. In contrast, as in my imaginings I think of hospitals, will be the other type of hospital-the one primarily concerned in medical investigation and medical education. Here special types of diseases will be admitted for study. Patients will remain much longer than in the former type of institution. Resident and visiting staff will be larger in proportion to number of patients than in a hospital primarily concerned in the expeditious care of patients. More staff members, possibly all, will devote their entire time to work within the walls of the institution. This type of hospital will have all the equipment for diagnosis and care of patients found in the other type of institution, and in addition extensive equipment for the investigation of such problems as are chosen for study. No form of laboratory of the biological and physical sciences, no type of apparatus should be foreign to such a hospital, provided the problems studied need them for their solution. Per capita cost for patients of necessity will be very high. In general terms such a hospital will be a laboratory for the investigation of biological problems and needs to be organized much as an institute of biology or physics or chemistry. Yet there is a very definite difference that never can be lost sight of. The hospital is peopled with patients that require all the diagnostic and therapeutic skill and the best of nursing care found in the leading hospitals of the land. The staff will need all the clinical acumen and judgment of the best of physicians and surgeons. Every problem should be so moulded that the humanity of the patient is the dominant idea which must determine and set the limits of methods of investigation. The ideal must be that nowhere will patients receive better care and a more highly organized service. The investigator, who in training and at heart is not a clinician, is out of place in such a hospital and most assuredly should not rank high in the scheme of organization. Problems, unconcerned with patients, had best be studied in the laboratories of pure science, not in the laboratories of the hospital. Workers in the hospital profitably can spend periods of study in other laboratories, and always there should be close contact with all members of the biological, physical and chemical institutes of the university. Such a hospital, not developed as an integral part of a university, will be greatly hampered in progress. In general terms I have just outlined my ideas of the second type of hospital. Its effectiveness will be measured, in large part, by its productivity in research. It is of this second type that the Albert Merritt Billings Hospital proposes to be, and along these general lines it needs to be organized. The University of Chicago, as I understand from various of its officials and professors, intends to try a great and on the whole a new experiment in medical education, in which this hospital will be an integral part, probably the most important part. The purpose of this school will be to train, as the main product, medical investigators and medical teachers rather than practitioners. Medicine is to be a graduate department of the university rather than a professional school; organization and development will be determined to that end. The number of students is to be small and particularly selected as potentially capable of development into investigators and teachers. The methods are to be those of the graduate schools of our universities. At once numerous difficulties will confront the organizers of such a school. The best method of selection of students is a serious problem. The success of your experiment will in large measure depend on its satisfactory solution. For some years now a number of medical schools have limited their student intake to those of particular collegiate training and of high rank. It must be confessed that no methods of selection, so far tried out, have proved to be very satisfactory. Our students of to-day certainly average better as the result of this selection, but many very mediocre men are admitted to all our schools, and many medical educators have grave doubts as to whether the number of really brilliant students in our classes has been much, if any, increased by our methods of selection. More important than this is our ignorance of how many we exclude who, if admitted, would have far excelled those actually chosen. You will need to find a better method of selection, or else your general scheme may be doomed to failure. Very likely you will in succession try and discard methods. Instead of small classes, a very large entering class, with subsequent reduction, may be necessary, or the development of some type of honors school within a larger school may be needed. It is not my place to suggest a method. Merely do I wish to point out that admission selection will be an important part of your experiment. As already indicated, size of classes will be another problem. The very obvious advantages of small groups of students in close contact with teachers may not offset the stimulation of association with a large body of students and the reduced probability of brilliant graduates incident to small numbers. Teaching methods present a different type of problem, as yet not satisfactorily solved in any of our schools. Great freedom to the individual student will be desirable, for genius thrives in the atmosphere of great opportunities, and yet there are limitations to this freedom in medicine not incident to |