lieved that these latter represent but questionable evidence for the presence of any true reducing substances, or if conceded to be positive evidence for such, it is held that the reducing substances can not be present in great amounts. An investigation of this series of changes from a colloid-chemical point of view reveals the fact that these color changes are coincident, not with differences in the nature of the reduction products, but only with differences in the size attained by the particles of reduced substance. If the copper oxide particles are brought down in very fine (subcolloid or colloid) form, the greenish discolorations are produced; as the copper oxide particles grow in size they become yellow, then orange, and when very coarse they are red. The series shows, in other words, what has been observed by different colloid-chemical workers: that one and the same material may, in the colloid state, show different colors, the color order following Wolfgang Ostwald's color law, according to which the most highly dispersed particles of a given substance are likely to be yellow, turning, as the size of the particles increases, to orange or red, and finally to violet, blue or black. As to which of these possible colors will be obtained from a Fehling's solution undergoing reduction depends upon the conditions surrounding the reduction, the greenish discolorations being obtained whenever the conditions are such as will keep the cuprous oxide, as produced, in its finely divided state; while the red will result when opposite conditions obtain. Three factors are chiefly concerned in the process: 1. Contrary to the generally accepted notion, the presence of too much reducing substance (as too much dextrose) is more likely to yield a greenish result than the presence of too little. This is because with much reducing substance the reduction starts from many points at once, but with exhaustion of the available copper salt the process comes to a halt before the cuprous oxide particles have attained any great size. substance present, the greenish discoloration will be obtained whenever materials are present in the reaction mixture which tend to stabilize the cuprous oxide in its finely divided form. Such materials are of the group of the lyophilic (hydrophilic) colloids and whenever present, either because added experimentally to reaction mixtures prepared in the laboratory or brought in with the mixtures being tested for reducing bodies (like diabetic urine) they incline to stabilize the cuprous oxide when this is still in a finely divided state. 3. With certain reducing substances (like dextrose) such "protective" hydrophilic colloids may be produced in the course of the reactions incident to the Fehling's test itself. In the action of the alkali of Fehling's solution upon dextrose, for example, there are produced, from a chemical point of view, not only the various degradation products which are responsible for the reduction of the copper salt, but, from a colloid point of view, many of these are colloid in nature and so tend to inhibit a precipitation of the cuprous oxide in coarse form. Consideration of these various facts not only renders intelligible many of the excellent empiric instructions which different chemists have long found useful when Fehling's test for the qualitative or quantitative determination of various reducing bodies is employed, but they indicate also what schemes should be followed if it is desired to get the copper oxide precipitated in its coarse red form. To allow adequate time for the growth of the cuprous oxide particles, it is better to make reductions at low temperatures than at higher ones. A Fehling's test carried out at room temperature by mixing the Fehling's solution with the suspected material and setting this aside for twenty-four hours is therefore more likely to yield a red precipitate than if the test is made by boiling the two together in the ordi nary way. Care should also be taken not to use excessive quantities of the material containing the reducing bodies. This not only avoids the possibility of using more reducing substance 2. Irrespective of the amount of reducing than there is available copper salt that may be reduced, but it minimizes the possibilities of adding excessive quantities of protective colloids which might stabilize the cuprous oxide in its finely divided form. Finally, in doubtful cases, a dilution of the reaction mixture is always to be tried. By this method there is avoided not only excessive concentration of the reducing body itself, but through adequate dilution, both those protective colloids which may be added from without, or those which may be formed in the reaction mixture itself are likely to be diluted to a point where their effect in stabilizing the cuprous oxide in its finely divided form is largely lost. II While working on the reduction of Fehling's solution by formaldehyde, we encountered a series of reactions which, while largely familiar to the physical chemists since Bredig's classical studies on the inorganic ferments, are somewhat new in their sum total; and since the reactions are strikingly like those observed in biological material, we have used them to elucidate the nature of such biological reactions for our students. Formaldehyde reduces a Fehling's solution not only to the ordinary cuprous oxide, but to the metallic copper. The copper comes down in colloid form, but as this happens, a second reaction ensues in which the metallic copper acts upon the formaldehyde and decomposes it with the liberation of hydrogen. The liberation of hydrogen continues for hours, until either all the formaldehyde has been decomposed or all the copper salt has been reduced. We use this reaction as a biological analogue illustrating the formation of an enzyme (the reduced copper) from a series of simple "dead" materials (alkali, salts, carbohydrate). From another point of view we may say that the formaldehyde poisons or acts as a toxin upon the Fehling's solution. Against this the reaction mixture produces an antitoxin (the metallic copper). The reaction may also be used to illustrate the action of different enzymatic poisons. Potassium cyanide, for example, when added to the Fehling's solution will not only prevent its reduction by the formaldehyde but, added after the reduction has been initiated, will inhibit or stop further reduction and liberation of hydrogen. As emphasized by Hoppe-Seyler, the production of nascent hydrogen is held to be essential in the chemistry of respiration. But depending upon whether this production of hydrogen in a biological oxidation mixture occurs in the presence or in the absence of oxygen, totally different effects (as an oxidation in the one case or a reduction in the other) may be brought about. The same is true of the chemistry of a Fehling's solution when reduced by formaldehyde. If a substance like methylene blue or phenolsulphonephthalein is added to the reaction mixture, these dyes are left untouched or are deoxidized, depending upon whether the reaction mixture is kept in a flat dish exposed to oxygen or in a tall tube from which oxygen is largely excluded. In other words, the first dye behaves just as in the classical experiments of Paul Ehrlich upon tissue oxidations; the phenolsulphonephthalein acts as in the experiments of E. C. Kendall. Phenolsulphonephthalein suffers reduction in the body whenever oxygen is absent while it is left untouched when this is not the case. A detailed account of these experiments has been sent to the Kolloid-Zeitschrift for publication. MARTIN H. FISCHER, MARIAN O. HOOKER EICHBERG LABORATORY OF PHYSIOLOGY, THE OIL CONTENT OF COTTON SEED AN ACCURATE BASIS FOR COMMERCIAL STANDARDIZATION As a result of four years' work by the author, three of which are shown in the table below, and based on more than 500 determinations in the cotton industry laboratory of the Georgia State College of Agriculture, it was found that the oil content of cotton seed is an inherent characteristic of the variety, and that the percentage of oil in any variety can be increased by selection with no corresponding loss of other desirable qualities. Al though there may be slight variations from year to year, depending upon the season, these environmental factors influence all varieties alike, and the seed of the varieties that were high in percentage of oil the first year have remained so during subsequent seasons. The seed of the same variety when grown on the sandy soil of the coastal plains produce uniformly less oil than when grown during the same season on the red clay soil of the Piedmont Plateau. This difference varies from 0.51 gallon to 2.3 gallons per ton of seed, depending upon the variety. In a general way the varieties with the highest proportion of meats to hulls produce the most oil; but there is no positive correlation between percentage of meats and the oil content, since the percentage of oil in the meats varies with the variety. TABLE SHOWING AVERAGE RESULTS OBTAINED WITH COTTON GROWN FOR THREE SUCCESSIVE Name of Variety Rexall........ 7.62 38.34 23.30 62.14 50.50 3.47 1,067 Average...... 7.56 41.94 20.94 55.84 44.76 3.36 1,030 1 Nitrogen determinations made by department of agricultural chemistry. The seed from cotton plants grown upon soil to which fertilizer high in nitrogen has been applied are uniformly higher in nitrogen than seed from plants of the same variety grown during the same season on soil not so liberally liberally supplied with this element-the average difference being less than one half of one per cent. The amount of nitrogen found in the seed from different varieties is fairly constant. In the seed of one variety only, did this variation exceed twenty-three hundredths of one per cent. The difference in the value of the cottonseed meal and the hulls, produced by a ton of seed from the variety yielding the most oil and the one yielding the least amount of oil was only forty-four cents, and the increased amount of lint on the seed of the inferior variety more than offset this difference. Therefore, there is practically no difference in the value of cotton seed aside from oil content, and the greatest variation between different varieties of seed in this respect was found in the season of 1914, when the percentages were 23.69 and 17.38, respectively. The average variation for three years was four and forty-two one hundredths per cent., or eleven and eight tenths gallons of oil per ton of seed. Taking the average price of seed for the same three years and the average yield of oil in gallons per ton of seed, it will be found that the price paid for the oil they contained was 82 cents per gallon. On this basis there is a difference in value of seed from the varieties of high and low oil content shown in the above table of $9.73 per ton. By eliminating the inferior varieties, the quality of the seed could easily be improved, thereby increasing their average value $5.00 per ton, and the present annual crush of more than five million tons would represent a sav ing of twenty-five million dollars per annum. This elimination could easily be effected if the seed were purchased on the basis of their oil that content, and these data show conclusively this is the only accurate basis of commercial standardization. LOY E. RAST GEORGIA STATE COLLEGE OF AGRICULTURE, ATHENS, GA. DEDICATION EXERCISES AT THE BROOKLYN BOTANIC GARDEN ON April 19-21 exercises were held in connection with the dedication of the completed laboratory building and plant houses of the Brooklyn Botanic Garden. The programs at the various sessions were as follows: APRIL 19 Formal exercises for officials, Garden members and invited guests. Lecture Hall, Mr. Alfred T. White, chairman of the Botanic Garden Governing Committee, presiding. Introductory Address, Mr. A. Augustus Healy, president of the Brooklyn Institute of Arts and Sciences. Address for the City of New York, Hon. William A. Prendergast, comptroller. The social, educational and scientific value of botanic gardens, Professor John Merle Coulter, University of Chicago. Addresses for the borough of Brooklyn, Hon. Lewis H. Pounds, president of the borough; for the Department of Parks, Hon. Raymond V. Ingersoll, commissioner of Parks, Brooklyn; for the Brooklyn Botanic Garden, Dr. C. Stuart Gager, director of the Garden. 10 P.M. Reception by the trustees and woman's auxiliary, inspection of building and view of exhibit on genetics, arranged in cooperation with the Cold Spring Harbor Station for Experimental Evolution of the Carnegie Institution of Washington. FRIDAY, APRIL 20 Dr. R. A. Harper, Torrey professor of botany, Columbia University, presiding. A vegetative reversion in Portulacca, A. F. Blakeslee and B. T. Avery, Station for Experimental Evolution, Carnegie Institution. Intercourses between self-sterile plants, E. M. East, Bussey Institution of Harvard University. Evolution by hybridization, E. C. Jeffrey, Harvard University. Binary fission and surface tension in the development of the Volvox colony, R. A. Harper, Columbia University. The nucleus as a center of oxidation, W. J. V. Osterhout, Harvard University. Modern applications of botany, Melville T. Cook, Rutgers College. Mycelium of certain species of Gymnosporangium, B. O. Dodge, Columbia University. Pathological problems in the distribution of perishable plant products, C. L. Shear, Bureau of Plant Industry, U. S. Department of Agriculture. Some botanical problems which paleobotany has helped to solve. (Read by title.) Arthur Hollick, Staten Island Association of Arts and Sciences. The ancient oaks of America. (Read by title.) William Trelease, University of Illinois. Further notes on the structural dimorphism of sexual and tetrasporic plants in the genus Galaxa ura, Marshall A. Howe, New York Botanical Garden. A quantitative study of Raunkiaer's growthforms as illustrated by the 400 commonest species of Long Island, N. Y. (Read by title.) Norman Taylor, Brooklyn Botanic Garden. 2 P.M. Dr. N. L. Britton, director-in-chief, New York Botanical Garden, presiding. The relation of crown-gall to other overgrowths in plants, Erwin F. Smith, Bureau of Plant Industry, U. S. Department of Agriculture. The Uredinales of Oregon, Herbert S. Jackson, Purdue University. The importation of phytopathogenes, W. H. Rankin, Cornell University. Physiological races of parasitic fungi, George M. Reed, University of Missouri. The genus Endogone, George F. Atkinson, Cornell University. A method of obtaining abundant sporulation in cultures of Alternaria solani, L. O. Kunkel, Bureau of Plant Industry, U. S. Department of Agriculture. The vegetation of our new West Indian Islands, N. L. Britton, New York Botanical Garden. Weather conditions and plant development, G. P. Burns, University of Vermont. American heaths and pine heaths, John W. Harshberger, University of Pennsylvania. Botanical training in the Agricultural College. (Read by title.) A. Vincent Osmun, Massachusetts Agricultural College. A duplicated leaf-lobe factor in Bursa, George H. Shull, Princeton University. Isolation as a factor in specific change, Edmund W. Sinnott, Connecticut Agricultural College. Further studies on the interrelationship of morphological and physiological characters in seedlings of Phaseolus, J. Arthur Harris, Station for Experimental Evolution, Carnegie Institution. Inheritance studies in Castor beans. (Read by title.) O. E. White, Brooklyn Botanic Garden. POPULAR SCIENTIFIC PROGRAM Mr. Alfred T. White, chairman of the Botanic Garden Governing Committee, presiding. Photographing wild flowers for color illustrations, Dr. Homer D. House, State Botanist of New York. Vacant lot gardening and children's gardens in Brooklyn, Miss Ellen Eddy Shaw, curator of Elementary Instruction, Brooklyn Botanic Garden. Problems of conservation in New York state, Hon. George D. Pratt, commissioner of Conservation of New York State. APRIL 21 Dr. H. M. Richards, Columbia University, presiding. The synchronism of plant structures, John M. Macfarlane, University of Pennsylvania. Contact stimulation, G. E. Stone, Massachusetts Agricultural College. The respiratory ratio of cacti, H. M. Richards, Columbia University. The absorption of calcium salts by squash seed lings. (Read by title.) R. H. True, Bureau of Plant Industry, U. S. Department of Agriculture. Duplication and cohesion in the main axis in chicory, A. B. Stout, New York Botanical Garden. The sequence of life in peat bogs. (Read by title.) W. W. Rowlee, Cornell University. Some observations on the sexuality of Spirogyra, H. H. York, Brown University. The problem of the imported plant disease as illustrated by the White Pine Blister Rust. (Read by title.) Haven Metcalf, Bureau of Plant Industry, U. S. Department of Agriculture. Outline of the history of the science of phytopathology, H. H. Whetzel, Cornell University. Tubers within tubers of Solanum tuberosum, F. C. Stewart, New York Agricultural Experiment Station. The rosy-spored Agarics of North America, W. A. Murrill, New York Botanical Garden. Some botanical-pharmacognostical investigations, Henry Kraemer, Philadelphia College of Phar Conference to consider Vacant Lot Gardening and how the Botanic Garden may become Most Helpful to Teachers Dr. C. A. King, Brooklyn Institute of Arts and Sciences and Erasmus Hall High School, presiding. Welcome, Dr. C. Stuart Gager, director of the Brooklyn Botanic Garden. The possibilities of vacant lot gardening in Brooklyn, Mr. H. F. Button, professor in the New York State School of Agriculture on Long Island. How may the Botanic Garden cooperate with local schools? Dr. Ralph C. Benedict, Bushwick High School; Miss Beatrice King, Public School No. 25; Miss Johanna Becker, Public School No. 36; Dr. Frederic Luqueer, Public School No. 152; Miss Margaret Kane, Public School No. 98; Mr. James O'Donnell, Public School No. 43; Mrs. Alice Ritter, Public School No. 89. Opportunities offered by the Botanic Garden, Dr. E. W. Olive, curator of Public Instruction. What the Botanic Garden is doing for Brooklyn boys and girls. (With brief statements by ten boys and girls.) Miss Ellen Eddy Shaw, curator of elementary instruction; Miss Jean Cross, assistant curator of elementary instruction. Tea was served at 4:30 P.M. by the Woman's Auxiliary of the Botanic Garden. THE STANFORD MEETING OF THE PACIFIC DIVISION OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE THE second annual meeting of the Pacific Division of the American Association for the Advancement of Science was held at Leland Stanford Junior University, California, between the dates, April 5 to 7, 1917. The headquarters of the Division were maintained in the rotunda of David Starr Jordan Hall, and the sessions of the several societies participating in the meeting were held in lecture rooms of the departments to which the societies were closely related. Three general sessions of the division were held, the first of which was a symposium on the afternoon of Thursday, April 5, Dr. J. C. Branner, president of the Pacific Division, presiding. This symposium had been prepared by Dr. D. T. MacDougal, director of the Desert Laboratory of the Carnegie Institution of Washington, Tucson, upon the subject, "Coordination and Cooperation in Research and in Applications of Science."' Four addresses were presented as follows: "Science, and an Organized Civilization," by Wm. E. Ritter, director, Scripps Institution for Biological Research, La Jolla, California. "The National Research Council as an Agency of Cooperation,” by Arthur A. Noyes, director of Chemical Research, Throop College of Technology, Pasadena, California. "Plans for Cooperation in Research among the Scientific Societies of the Pacific Coast," by J. C. Merriam, professor of paleontology, University of California, Berkeley. "The Applications of Science," by William F. Durand, professor of mechanical engineering, Stanford University, California. On the evening of Thursday, April 5, a general session was held in the assembly hall of the Outer Quadrangle, Dr. J. C. Branner, president of the division, presiding. At this session, President R. L. Wilbur welcomed the association on the part of the university, and Dr. James A. B. Scherer, president of Throop College of Technology, responded. In this response President Scherer extended the invitation of Throop College of Technology and other institutions of southern California to the Pacific Division of the American Association to hold its 1918 meeting in Pasadena. The nominating committee presented its report, nominating the following members to serve upon the Executive Committee for a term of three years each: Dr. W. W. Campbell, director of the Lick Observatory, Mount Hamilton; Dr. Wm. E. Ritter, director of the Scripps Institution for Biological Research, La Jolla, California, and Mr. C. E. Grunsky, president of the American Engineering Corporation, San Francisco. This report was accepted and the secretary was instructed to cast the ballot for these names. Following the transaction of this business, Dr. J. C. Branner, the retiring president of the Pacific Division of the American Association, presented his presidential address upon the subject, "Some of |