He was largely instrumental in securing from the telephone and telegraph companies of the United States the best talent available to meet the urgent requirements of the Signal Corps at the outbreak of the war. He has served

with marked distinction as a member of the American Expeditionary Forces and his brilliant professional attainments and sound judgment have rendered his services of exceptional value to 'the government."

sanitary experts arrived in Panama, on April 3, and left April 7, for Guayaquil, Ecuador, to investigate sanitary conditions.

PROFESSOR HERBERT E. GREGORY, of Yale University, leaves on May 8 for Honolulu to

assist the trustees of the Bernice Pauahi Bishop Museum in developing plans for scientific work in Hawaii. By arrangement between the museum and Yale University, Professor Gregory is to be absent from New Haven for the remainder of the present academic year and also during the second half of the year 1919-20.

DR. A. HAMILTON RICE, of Boston, will start

MISS LUCY MINNEGERO, of Fairfax, Va., chief nurse of the American Red Cross Unit, which was sent to Kief, Russia, in 1915, and later superintendent of nurses at Columbia Hospital, Washington, D. C., and who since 1917, has been in charge of the preparation of the Red Cross nurses for assignment overseas, has been appointed superintendent of the U. S. Public Health Service Nurse Corps.

PROFESSOR C. M. CHILD, president of the American Society of Zoologists, has nominated and the executive committee has unanimously elected the following members of the society as its representatives in the reorganized Division of Biology and Agriculture of the National Research Council: F. R. Lillie, G. H. Parker and M. F. Guyer.

DR. C. LOVATT EVANS, professor of physiology and pharmacology at Leeds, has resigned to undertake research work in the department of pharmacology and biochemistry of the med; ical research committee.

DR. SOLON SHEDD, head of the department of geology, State College of Washington, has been granted leave of absence for a year to engage in the production of casing head gasoline in the Oklahoma oil fields.

MAJOR GENERAL WILLIAM C. GORGAS, former Surgeon-General of the Army, and a party of

tion in South America. The United States government will receive from Dr. Rice the results of his geological discoveries upon his return, as has been the case following each of his previous voyages. His biological and ethnological collections have been presented to the Peabody Museum, Harvard University. To navigate the shallow waters of the Upper Amazon, Dr. Rice has had built a 45-foot launch, which is of 14-foot beam and only 20 inches draught. It will be shipped by freight to one of the South American ports and there assembled. The boat contains living quarters and a laboratory.

AT a meeting of the International Association of Poultry Instructors and Investigators held in London, England, March 11-15, 1919, Edward Brown, Fellow of the London Society, was reelected president, and William A. Lippincott, professor of poultry husbandry, Kansas State Agricultural College, as has been noted in SCIENCE, was elected secretary to succeed Dr. Raymond Pearl. Dr. Pearl recently resigned, since, in becoming head of the department of biometry and vital statistics in the school of hygiene and public health, Johns Hopkins University, he is no longer carrying on investigations with poultry. Dr, Pearl was made first fellow of the association in recognition of his untiring service as secretary since the organization of the association in 1912. By invitation of the Netherlands government, a World's Poultry Congress will be held at the

Hague in 1921 under the auspices of the International Association of Poultry Instructors and Investigators.

LORD RAYLEIGH, who recently accepted the presidentship of the British Society of Psychical Research, gave his presidential address on April 11.

PROFESSOR FRANCIS CARTER WOOD, director of cancer research under the George Crocker Special Research Fund, Columbia University, lectured on April 15, before the Georgia State Medical Society and the students of Emery University, at Atlanta, Ga.

DR. C. K. EDMUNDS, president of the Canton Christian College, spoke at the Cosmos Club, Washington, D. C., on April 14, on "Thirty Thousand Miles in China." The lecture was illustrated by lantern slides. Dr. Edmunds is lecturing on scientific aspects of China at different institutions.

MR. G. S. BAKER has given £500 for the foundation at University College, London, of a prize for the encouragement of botanical research to be named after his daughter, the late Dr. Sarah M. Baker, an old student and member of the staff of the college.

GEORGE CARLTON WORTHEN, of the Bussey Institution, Harvard University, known for his work in economic botany, died on April 10, aged forty-eight years.

DR. HENRY WILDE, F.R.S., the English physicist died on March 29, at eighty-six years of age.

SIR EDWARD CHARLES STIRLING, professor of physiology at the University of Adelaide, and director of the South Australian Museum, died on March 20, aged seventy years.

THE Experiment Station Record notes that the renewed receipt of scientific literature from Germany brings news of the death of Geheimrat Bernhard Tollens, of the University of Göttingen. He died on January 31, 1918, in his seventy-seventh year. A graduate of Göttingen, Dr. Tollens spent several years as assistant in chemistry at Heidelberg and in Paris, going for a year to Portugal, but returned to Göttingen in 1879 as assistant to the

famous chemist Wöhler. Three years later he became director of the Agricultural Chemical Laboratory of the Agricultural Institute, occupying that position up to the time of his retirement in 1911. Professor Theodore Dietrich, known for his work on animal nutrition, was director of one of the earliest German experiment stations, established at Haidau in the district of Cassell in 1857, and removed to Marburg in 1880. He died on October 1, 1917, in his eighty-fifth year.

WE learn from Nature that at a special general meeting of the Geological Society, held in London on March 26, the following resolution of council was carried by 55 votes against 12: "That it is desirable to admit women as fellows of the society." In submitting the motion, Mr. G. W. Lamplugh, president of the society, said: "It will be within the recollection of most of the fellows that the question of the admission of women to candidature for the fellowship of the society has been raised on more than one occasion in the past. It was considered in 1889 and 1901, and, again, more systematically in 1908-09, when a poll of the fellows was taken and three special general meetings were held, with inconclusive results. It is generally recognized that the course of events since these dates has materially changed the situation. Women have been welcomed to our meetings as visitors, and we have had many examples of their qualifications for fellowships in the excellent papers which they have from time to time contributed to the society. The value of these papers has been appreciated by all geologists, and has been repeatedly acknowledged by the council in its awards. Therefore, in the opinion of the council, it is no longer reasonable to maintain a sex-bar against qualified candidates for the fellowship of the society, and I am empowered by the council to submit the above-mentioned resolution for your consideration."

THE summer session of the Hopkins Marine Station of Stanford University, situated on Monterey Bay, California, begins on June 17. This session corresponds to the summer quarter of Stanford University, the first half quarter ending on July 23, and the quarter, August

29. There will be six instructors in attendance and ten regular courses are offered, including work in general zoology and physiology, the classification and ecology of marine invertebrates, economic zoology with reference to marine invertebrates and to fishes, invertebrate embryology, marine botany and special work. An announcement will be sent on application to the Hopkins Marine Station, Pacific Grove, California.

PROFESSOR JA. UDDEN, director of the Bureau of Economic Geology and Technology of the University of Texas, reports that much light upon the possible mineral contents of Texas may be obtained by the keeping of records of the holes that are being drilled in search of oil in various parts of the state. It is the theory of many geologists that large potash beds underlie parts of west Texas, and it is thought that this, or other valuable mineral may be discovered in the wild-cat oil wells that are now being drilled in nearly all the counties of west Texas, though oil is not brought to light. Two years ago the United States government sent seven men, experts in their several branches, to Cliffside, twelve miles north of Amarillo, where a permanent camp was established, a first-class derrick put up, and a complete laboratory established to make exhaustive studies of the salts that might be obtained. The results of this investigation have not been published so far, but it is believed enough has been found to warrant further observations. Potash has been found but not in workable quantities. For the present it is not expected that further explorations will be made by the government. The laboratory established at Cliffside, however, will continue to examine cores from any wells that may be sent in. The Bureau of Economic Geology and Technology of the university has also made similar analyses and will continue to make them.

THE Mexico City correspondent of the Journal of the American Medical Association writes that according to recently published statistics, there were 21,915 deaths recorded in the city of Mexico during 1918,

and only 7,542 births, which seems to indicate that the population has been reduced by 14,373. But this last figure can not be regarded as accurate because there are always a number of persons who fail to comply with the official regulations for notification in the respective bureaus of the birth of their children. But even making allowance for all this, there is no doubt that the death rate exceeded the birth rate. Influenza was responsible for 1,935 deaths, syphilis for 232, bronchitis for 1,556, bronchopneumonia for 1,456, pneumonia for 2,312, enteritis for 5,496, and various ailments for the other deaths.

Nature states that the Linen Industry Research Association of Belfast is about to appoint a director of research at a salary of not less than £1,000 per year. The selected candidates will be expected to make a survey of the entire field of research in the linen industry, to draft a program of research, and to organize and supervise the carrying out of the scheme.

Two new greenhouses are being completed at the New York Botanical Garden, built through a gift of $100,000 made for the purpose two years ago by Daniel and Murray Guggenheim. These greenhouses form a part of Public Conservatory Range No. 2 on the eastern side of the garden. The larger of the two is designed as a central display greenhouse. Included is a large room where lectures on plant life will be delivered. The smaller of the new greenhouses is designed as an orchid greenhouse to hold the large collection of orchids already accumulated at the garden and others which will be brought from tropical America.

OWING to a reduced appropriation for its work, the American Museum of Natural History finds it necessary greatly to curtail its activities, and announces that one half of the exhibition halls-about 17, it is estimatedhave been closed because of lack of funds to pay attendants. The museum is now open from 10 to 4, instead of from 9 to 5, daily. Retrenchment plans include also the elimination of evening lectures in the museum build

ings and in public schools under the auspices of the museum and a 50 per cent. curtailment of lectures for school children in the museum. All of these measures are designed to cut down expenses for fuel, light, and service, as the minimum appropriation of $240,000 asked for by the museum, figured to cover regular expenses only without provision for further development, has been cut down to $200,00 in the city budget.

By the will of the late Major S. Field Thorn, who died recently in San Francisco, the California Academy of Sciences is to receive

Cragthorn Park," near Santa Cruz, California. The place consists of 242 acres and was Major horn's country home. After the various specific bequests have been paid the academy is to receive the balance of the estate, which it is thought will be considerable. Major Thorn was at one time manager of the Palace Hotel in San Francisco and was for many years interested in the Academy of Sciences.

IN connection with the spring meeting of the American Physical Society at the Bureau of Standards, Washington, on April 25 and 26, there will be an exhibit of physical apparatus illustrative of war developments in physics. The exhibit was opened on the afternoon of the 24, all day on the 25 and 26, the evening of the 25 and the afternoon of the 28.

UNIVERSITY AND EDUCATIONAL
NEWS

HARVARD UNIVERSITY and the Smithsonian Institution receive $50,000 each by the will of Mrs. Virginia Purdy Bacon. Columbia University receives $25,000 for scholarships.

By the will of Alexander Cochrane, late of Boston, and head of the Cochrane Chemical Company, Peter Bent Brigham Hospital will receive $10,000 for the establishment of a free bed, and at the termination of a trust fund created for benefit of the members of Mr. Cochrane's family the principal of the trust is to go to Harvard College.

THE University of California receives by the will of Mrs. Phoebe Hearst, $60,000, to

continue scholarships and a valuable collection of paintings, tapestries and objects of art.

PROFESSOR WILLIAM A. NOYES, head of the department of chemistry of the University of Illinois; Professor Frank Morley, of the Johns Hopkins University, and Professor William T. Sedgwick, of the Massachusetts Institute of Technology, will be included in the faculty of the summer session of the University of California, giving respectively courses in chemistry, mathematics and public health.

Ar the agricultural college of the University of Idaho, Herbert P. Davis, dairy husbandman, Dairy Division, U. S. Department of Agriculture has been appointed dairyman of the Agricultural Experiment Station, and vice director of the station, and J. E. Nordby, lately first lieutenant in the Motor Section of the Aviation Service, has been appointed associate animal husbandman of the Agricultural Experiment Station, and will have charge of experimental work in animal husbandry.

CAPTAIN JAMES RIDDICK PARTINGTON, has been appointed to the newly established university chair of chemistry, tenable at East London College.

Nature states that Professor Ludwig Jost, of Strasburg, succeeds at Heidelberg Professor G. Klebs, who died last October in his sixtyfirst year, and Dr. W. Ruhland, of Halle, succeeds Professor von Vöchting at Tübingen.

DISCUSSION AND CORRESPONDENCE
BASIS OF THE GEOMETRICAL MEAN AS A
B. COLI INDEX

COULD I have realized that Professor Cairns would honor by mathematical consideration the "Geometrical Mean" (SCIENCE, March 8, 1918) method of obtaining a bacteriological index, I should have hesitated to "wander into paths outside my own domain." However, no elaborate discussion of the mathematical relation between the theory of chance variation and the geometrical mean can be expected to induce the empirical bacteriologist to use it as a B. coli index. The simplicity of application and practical utility in daily routine will in the end be its recommendation. Still a brief mention of the grounds on which it seemed to

be based may help to establish it until fuller treatment is possible.

Professor Phelps has thrown light on the problem by distinguishing between the distribution of B. coli in space and its distribution in time. The former alone is discussed by McCrady in treating of fermentation tubes made from a single sample. The latter furnished the data for suggesting the " geometrical mean," which was based on a large number of samples taken at different times from single sources, as, for example, given points on a river. Both methods accomplish the same practical purpose by obtaining a weighted mean which eliminates the undue influence of positive high dilutions and the results differ from each other only by a factor which is nearly constant. Whether we wish to base the method à priori on the theory of probability or upon the actual form of the data, becomes an academic problem, but in practise the simpler is naturally to be preferred.

The arbitrary application of the conventional theory of chance to physical data can always be questioned. Bertrand in his "Calcul des Probabilités" calls attention to the fact that if a quantity varies as the law of chance, any observed function of that quantity does not, whereas the choice of the quantity is arbitrary. This distinguishes the mathematical theory of probability from the theory of chance variations of observed quantities. The number and magnitude of the forces acting to change a physical quantity may vary according to the law of chance, whereas the observed change is some function of those forces. Generally those forces combine as a product instead of a sum and so it is believed more fundamental that proportional variations instead of absolute variations follow the conventional law. In physics the variations are very small compared to the arithmetic mean value of the observed quantity and the effect may be commonly negligible because the proportional and absolute variations approach each other. The average is in such cases a 1 Jour. Infect. Dis., 1915, 17, p. 183.

In the end, therefore, we are thrown back upon the data themselves to determine the most fitting method of reduction and, as the Pearson School of statistics teaches, the sole purpose of such methods is to obtain some representative value of the data. Fortunately, Allen Hazen has given us in probability paper, a simple and sufficiently accurate graphical method of analyzing such rough data. Professor Whipple has summarized and plotted a large mass of bacteriological results and shows that they follow a logarithmic probability curve closely enough. The results obtained in the Investigation of the Potomac River show also that the logarithmic summation curves are strikingly symmetrical about the median line. In the results obtained at the Washington Filtration Plant over a five-year period, the distribution of turbidity readings were found to agree with this form of curve, and the bacteriological results are almost parallel. It is further believed that the practical evolution of the geometrical scale of dilutions indicates that where variations are great the arithmetical scale is but an approximation over short portions of the more natural and fundamental geometrical scale.

2 Galton, Francis, "Geometric Mean in Vital and Social Statistics," Proc. Roy. Soc., 29, p. 365, 1879.

3 McAllister, Donald, "The Law of the Geometric Mean,'' ibid., p. 367.

Whipple, Geo. C., "The Elements of Chance in Sanitation," Jour. Franklin Institute, Philadelphia, CLXXXII., 37, 205, 1916.

5 Hygienic Laboratory Bulletin No. 104. Table 13, pp. 87-94, and Charts E-H bet. pp. 128-129.

6 Wells, Wm. Firth, "Some Notes on the Use of Alum in Slow Sand Filteration," Proc. Am. Water Works Assn., 1913.