ON THE RELATIONSHIP BETWEEN FREEZING POINT LOWERING, A, AND SPECIFIC ELECTRICAL CONDUCTIVITY, K, OF PLANT TISSUE FLUIDS

THE problem of the contribution of nonelectrolytes, of undissociated molecules of electrolytes, and of dissociated ions of electrolytes to the depression of the freezing point, A, in terms of which osmotic concentration is usually measured, is one of considerable biological importance. We desire to know, for example, whether an observed difference in the osmotic concentration of the tissue fluids of a species growing in two different habitats is due primarily to differences in the quantities of electrolytes absorbed from the medium or to differences in the quantities of organic substances elaborated. The same question naturally arises when one is comparing the osmotic concentration of the tissue fluids of different species in the same habitat.

In the mixed solutions with which the biologist has to deal the problem presents serious difficulties. In certain cases some progress may be made by determining the correlation between the freezing point depression, A, and the specific electrical conductivity, K.

As a specific illustration we may take the relationship between osmotic concentration and electrical conductivity in a series of plant species growing in the non-halophytic habitats of the north shore of Long Island.1

In a series of 19 species of trees, 36 species of shrubs, and 162 species of herbs both A and

1 Protocols of data and full details are given in a paper in press in the Journal of Physical Chemistry.

Our problem is to determine whether higher values of K are associated with higher values of A, or whether within each of these growth forms2 these two constants of the solution are essentially independent.

Determining the correlation coefficients by the usual product moment method we have the following measures of relationship between the magnitudes of K and ▲ in the various series.

For trees, N=19, r=+0.127.152
For shrubs, N=36, r=— — 0.079.112
For trees and

shrubs, N=55, r=+0.022 ± .091 For herbs, N=162, r= = +0.150.052 For ligneous plants the correlations between A and K are low and statistically insignificant in comparison with their probable errors. The coefficient for shrubs is actually negative in sign. That for trees and shrubs together is sensibly zero. The coefficient for herbaceous plants is also low but may indicate a slight relationship between the two constants, higher values of A being associated with higher values of K and vice versa.

These results show that, in the vegetation of the glacial moraines of Long Island at least, there is practically no relationship between the concentration of ionized electro

2 It is necessary to separate the growth forms, since, as shown in detail elsewhere (Harris, Gortner and Lawrence, loc. cit.), the growth forms are highly differentiated with respect to both A and K. The actual means are:

lytes and of total solutes (molecules and ions) in the leaf tissue fluids.3

J. ARTHUR HARRIS, Ross AIKEN GORTNER, JOHN V. LAWRENCE

THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE MINUTES OF THE EXECUTIVE COMMITTEE OF THE COUNCIL

THE meeting was called to order at the Hotel Belmont, New York City, on October 17, at 11 A.M., with Dr. Simon Flexner in the chair. The following members were present: Cattell, Fairchild, Flexner, Humphreys, Livingston, Nichols, Osborn. 1. Minutes of last meeting (published in SciENCE, May 7, 1920) were approved.

2. Audited report of retiring permanent Secretary (Dr. L. O. Howard, for period from November 1, 1919, to April 1, 1920, was accepted and ordered to be filed and published in SCIENCE.

3. Summarized report of new permanent secretary (Dr. Burton E. Livingston) for period from April 1 to September 30, 1920, was accepted and it was ordered that such parts of it be published in SCIENCE as seem desirable to the permanent secretary. (The financial statement will be presented to the council before publication; other features will shortly appear in SCIENCE.)

4. Election of section officers.-Dr. A. E. Jenks was elected to be vice-president and chairman of Section H (Anthropology). Dr. E. A. Hooton was elected secretary of Section H.

5. A special committee on the organization of Section H (Anthropology), which is a new section, formed by the division of the old Section of Anthropology and Psychology, was established, this committee to be appointed by the president and permanent secretary in collaboration and to cooperate with the section officers just elected. (This committee will shortly be announced in SCIENCE.)

6. Present permanent secretary was nominated to the council, to continue to serve during the ensuing 4-year term as heretofore; that is for one third of his time.

7. Other nominations for Association officers 3 This result holds within the individual classes. In comparing ligneous and herbaceous growth forms we note that the growth form with the higher total concentration has the lower conductivity. This is shown by the fact that the ratio of KX 106 to A is 10923/1.217 for trees and shrubs but 14308/0.846 for herbs.

(president, general secretary, treasurer, five council members, two executive committee members). It was voted that these nominations be made at the first meeting of the council at Chicago and that elections occur at a later meeting of the council.

8. Nominations for Committee on Grants (3 members), to be appointed by the president with advice of the council. The executive committee recommends to the council that it is desirable to nominate members who are not now members of the Grants Committee, but the various branches of science should continue to be severally represented as heretofore. This matter should receive attention at first Chicago meeting of Council and nominations should be made at second meeting.

9. Science News Service, supported by Mr. W. E. Scripps. Dr. J. McK. Cattell and Dr. Geo. T. Moore were elected to represent the association in an advisory committee of this service.

10. Editorial Committee for Science.-It was voted that this committee continue to be constituted as heretofore; namely, of (a) its original members, (b) the chairman of the association sections for each year, and (c) the members of the executive committee.

11. Determination of the chairman of Executive Committee. It was voted that chairman of this committee is to be elected by the committee at its last session at each 4-year meeting of the association, the term of office of the chairman to be for no more than four years.

12. Election of Fellows.-Three hundred and seven members were elected to fellowship, their nominations having been received from the following sources: by Secretary of Section A, 6; by Secretary of Section B, 37; by Secretary of Section E, 35; by Secretary of Section G, 162; by Secretary of Section O, 5; by Secretary of Section Q, 56; by permanent secretary, 6. It was voted that nominations for fellowship received by the permanent secretary shall hereafter be referred to the secretary of the proper section, so that all nominations shall come to the executive committee from the section secretaries. (Nominations for fellowship should be sent to section secretaries rather than to permanent secretary. Section secretaries are urged to send their lists of nominations to the permanent secretary in time so that they may be acted on at each meeting of the executive committee.)

13. Auditor for permanent secretary's annual report. The resignation of Mr. Herbert A. Gill was accepted and filed, and the committee passed

a unanimous vote of thanks to Mr. Gill for his valuable and much appreciated services as auditor. The appointment of an auditor for this year was referred to the president and permanent secretary, with power.

14. Organization of Committee on Grants.-It was voted that Committee on Grants shall elect its chairman and secretary.

15. Place of 1922-23 annual meeting.-This was discussed, and Boston was tentatively recommended. (The 1921-22 annual meeting is to be held at Toronto.)

16. Expenses of section secretaries attending annual meetings.-It was voted to recommend to the council that Art. X., Sect. 2, of the by-laws be so amended as to authorize the permanent secretary to pay section secretaries who attend annual meetings a refund amounting to four cents per mile for the round trip in each case.

17. Expenses of section secretaries attending the Chicago meeting. The permanent secretary was authorized to refund to each section secretary attending the Chicago meeting a sum amounting to four cents per mile for his round trip.

18. Expenses of executive committee members attending spring and fall committee meetings. It was voted to recommend to the council to take under consideration the amendment of Art. X., Sect. 3, of the by-laws so as to authorize the permanent secretary to pay executive committee members attending spring or fall meeting of this committee a refund amounting to four cents per mile for the round trip in each case.

10. Sonora and Chihuahua.-It was voted to recommend to the council that Art. VI., Sect. 1, of the by-laws be so amended as to remove the Mexican states of Sonora and Chihuahua from the province of the Pacific Division and to place them in that of the Southwestern Division.

20. Benjamin collection of portraits and autographs of association presidents.—It was voted to recommend to the council that it authorize the permanent secretary to purchase for the association the Benjamin collection of portraits and autographs of the presidents of the association (74 portraits, each with autograph letter), at a price of $300.

21. Proposal to inaugurate a section on History of Science.-This action has been recommended by a large number of members. The proposal was thoroughly discussed but the committee did not feel justified in recommending it, since the proposed section would not be coordinate with the sections already established. It was suggested

that this very desirable aspect of scientific advancement (which is thoroughly approved by the committee) be organized in the new section L (Historical and Philological Sciences), to which it appears logically to pertain,

22. Committee vote by mail.-It was voted that Professor Pickering's method for voting by mail be generally used by the permanent secretary when such voting of this committee is requisite.

23. The Gamma Alpha Graduate Scientific Fra ternity was made an affiliated society by vote of this committee. (It will have two representatives in the association council.)

24. Affiliation of state academies.—It was voted to extend the special offer on this subject through 1921. Academies becoming affiliated before October 1, 1921, are to receive from the permanent secretary a payment amounting to one dollar for each academy member who has paid his annual dues ($5) to the association for the year 1921.

25. Stationery for use of section secretaries.— Proposal that permanent secretary's office furnish uniform stationery to all section secretaries was referred to permanent secretary, with power.

26. Sectional committee personnel.-It was voted that when an affiliated society embraces more than a single section of the association, its representatives in the association council shall not be members of any sectional committee.

27. Railway rates for annual meetings.—It was voted that the permanent secretary be instructed to investigate the basis on which reduced railway rates are sometimes granted to societies, with the aim of obtaining these rates for annual meetings of the association in the future. (Reduced rates for the Chicago meeting have been denied.) The committee adjourned at 4.

BURTON E. LIVINGSTON,
Permanent Secretary

Cornell University Medical College

1st Avenue and 28th Street

NEW YORK, N. Y.

ADMISSION to the first year class will be limited to seventy-five students in the New York and Ithaca Divisions combined. Subsequent admissions to any class will be made only if the number falls below sixty, when students from other institutions may be accepted, provided they fill all of our requirements.

The number of students in this College having been limited, that its advantages may be equalized to all parts of the State and country, not more than five students from any one college will be admitted to the first year class. Graduates of approved colleges are eligible.

INSTRUCTION begins September 27th, 1920. Laboratory methods are emphasized throughout the course and small sections acilitate personal contact between the students and instructor. Clinical instruction is given in the Bellevue, New York Nursery and Child's, Memorial, Manhattan State and Willard Parker Hospitals.

The tuition fee is $250.00 per annum.

Applications for admission to the first year should be received not later than July first. A catalogue and application blanks may be obtained by addressing the Dean.

Address

THE DEAN, 477 1st Ave., New York, N. Y.

Washington University

School of Medicine

REQUIREMENTS FOR ADMISSION

Candidates for entrance are required to have completed at least two full years of college work which must include English. French or German, and instruction with laboratory work in Physics, Chemistry and Biology.

INSTRUCTION

Instruction begins on the last Thursday in September and ends on the second Thursday in June. Clinical instruction is given in the Barnes Hospital and the St. Louis Children's Hospital, affiliated with the medical school, the St. Louis City Hospital, and in the Washington University Dispensary.

COURSES LEADING TO ACADEMIC
DEGREES

Students who have taken their premedical work in Wash ington University, are eligible for the degree of B.S. upon the completion of the first two years of medical work.

Students in Washington University may pursue study in the fundamental medical sciences leading to the degree of A.M. and Ph.D.

TUITION

The tuition fee for undergraduate medical students ia $200 per annum. Women are admitted.

The catalogue of the Medical School and other information may be obtained by application to the Dean.

Euclid Avenue and Kingshighway St. Louis

Entrance Two years of a recognized course in arts or in science in a registered college or Requirements School of Science, which must include Physics, Chemistry, Biology, and French or German. Six and seven years' combination courses are offered.

The First Two Years

The Third Year Course

The Fourth Year Course

are spent in mastering by laboratory methods the sciences fundamental to clinical medicine.

is systematic and clinical and is devoted to the study of the natural history of disease, to diagnosis and to therapeutics. In this year the systematic courses in Medicine, Burgery and Obstetrics are completed.

is clinical. Students spend the entire forenoon throughout the year as clinical clerks in hospitals under careful supervision. The clinical clerk takes the history, makes the physical examination and the laboratory examinations, arrives at a diagnosis which he must defend, outlines the treatment under his instructor and observes and records the result. In case of operation or of autopsy he follows the specimen and identifies its pathological nature. Two general hospitals, one of which is owned and controlled by the University, one special hospital and the municipal hospitals and laboratories are open to our students. The afternoons are spent in the College Dispensary and in clinical work in medical and surgical specialties and in conferences.

"Summer School-a summer course in pathology covering a period of six weeks during June and July will be given in case there is a sufficient number of applicants.

Address the Secretary of the College, 307 Orange Street Syracuse, N. Y.

Louisiana

SCHOOL OF MEDICINE

(Established in 1834)

ADMISSION: All students entering the Freshman Class will be required to present credits for two years of college work, which must include Chemistry (General and Organic), Physics and Biology, with their laboratories, and at least one year in English and one year in a modern foreign language.

COMBINED COURSES: Premedical course of two years is offered in the College of Arts and Sciences, which provides for systematic work leading to the B.S. degree at the end of the second year in the medical course.

School of Pharmacy, School of Dentistry and Graduate School of Medicine also.

Women admitted to all Schools of the College of Medicine

For bulletins and all other information, address

Tulane College of Medicine

P. O. Box 770
New Orleans, La.