thyst of Fujiya, Hoki Province, must be noted, and rose quartz is found at Gota. Maki Province (pp. 46, 47). Inclusions of quartz come chiefly from Mukaiyama and Takemori, the green fibrous inclusions being epidote and the brown fibrous ones tourmaline; included sulphur of a beautiful yellow is limited to quartz of Takemori. Fluid inclusions are quite common, being usually distributed irregularly throughout the crystal, though sometimes in definite layers parallel to the faces of the rhombohedron (p. 44). Felspar, tourmaline and garnet are here found in association with quartz. Localities well known since ancient times for beautiful quartz crystals are the granitic regions around Kimpû-zan, Kai Province. Here colorless and transparent crystals for ornamental work have been obtained for centuries (p. 38). It is well known that the manufacture of beautiful crystal balls has long been carried on in Japan. A small crystal of crysoberyl has been found in stanniferous sand of Takayama, Mino Province; it was of a pale greenish-yellow color (p. 82). Beautiful crystals of vivianite were at one time met with at Ashio, Shimotsuke Province. At first they were light blue, but became darker on exposure to the air (p. 86). Some blue, transparent crystals of tourmaline have been found at Takayama, Mino Province, and beryl found here resembles the tourmaline in color and form, one end of the crystal being of a lighter hue, while the other end is decidedly darker and only semi-transparent. The topaz, however, is the most conspicuous of the gems found in Japan and Dr. Wada gives a very full account On exposure to daylight the brown and brownish-yellow shade into blue, and the blue tends to become colorless. The brown hue is confined to a few freshly-quarried specimens, and is never observable in those which have been kept long in daylight. In some specimens the structure is shown by inclusions arranged parallel to the outline of the crystals, producing the strange effect observable in the so-called "phantom quartz." The most beautiful of the topaz crystals illustrated by Dr. Wada (Plate XXIV., Fig. a) was found between 1870 and 1880. It came later into the possession of Count K. Inowe who presented it to Dr. Wada. It measures 84 mm. in length, 64 mm. in the longer diameter and 51 mm. in the shorter. It is based on a piece of felspar, and on the side is black quartz crystal, the topaz standing nearly perpendicular to its prismatic faces. NEW YORK CITY GEO. F. KUNZ SPECIAL ARTICLES SEVERAL reasonable objections have dissatisfied bacteriologists with the present methods of estimating the average number of B. coli in water. The following method is proposed as a simple, convenient, and theoretically desirable means of arriving at a numerical index representing such a series of results. It was suggested in 1912 by data obtained at the Washington Filter Plant,2 and has since been practically applied with much success. Data-B. coli are determined to be present or absent in a series of fermentation tubes of ten, i. e., 10 c.c., 1 c.c., .1 c.c., .01 c.c., .001c.c., etc. Example: Suppose twenty samples or series of tubes gave the following results, where + or positive means B. coli were found present, both of the occurrences and of the crystallo- containing portions of the sample in multiples graphic forms (pp. 89-113). It occurs in pegmatite veins in granite as in Takayama and Hosokute, Mino Province, Ishigure, Ise Province, and Tanokamiyama, Omi Province. Japanese topazes were first exhibited in the National Exposition of Tokio in 1877. Six different hues have been observed, as follows: (1) Colorless; (2) wine-yellow, or bluish-yellow; (3) pale blue; (4) pale brown and pale blue in sectors; (5) pale green; (6) brown. 1 Report of the Committee on Standard Methods, American Public Health Association, 1916. 2 Wells, W. F., "Some Notes on the Use of Alum in Connection with Slow Sand Filtration at Washington, D. C.," Proceedings of American Water Works Association, 1913. Score. The decimal part of the Average Dilution Positive" gives the "Score," and the integral part tells how many figures to point off. The reason for calling it a Score " is that it is directly comparable to the bacteriological score of oysters.1 In the above example, the Score" would be 3.5. For all ordinary purposes, the "Score" is a very good index and can be used directly. Geometrical Mean.-The "Score" can be converted into the "Geometrical Mean" from the following table: TABLE FOR CONVERTING SCORE INTO GEOMETRICAL 01234567 8 9 MEAN 0 1 2 3 4 5 6 7 8 9 100 102 105 107 110 112 115 118 120 123 126 129 132 135 138 141 145 148 151 155 159 162 166 170 174 178 182 186 191 195 200 205 209 214 219 224 229 235 240 246 251 257 263 269 276 282 289 295 302 309 317 324 331 339 347 355 363 372 381 389 398 407 417 427 437 447 457 468 479 490 501 513 525 537 550 562 576 589 603 617 631 646 661 676 692 709 725 741 759 776 794 813 832 851 871 891 912 933 955 977 From the previous example, the "Score" 3.5 becomes "Geometrical Mean" 2. 24, which is not very different. Either represents an approximation sufficiently close to be considered the number of B. coli per c.c. Percentage Method.-The same results are given by an alternative method, which may sometimes be more convenient. Compute the percentages that are positive in each Dilution." The resulting figures should extend from a "Dilution" at which 100 per cent. are positive to one at which 100 per cent. are negative. The percentages are then added, and will give a number of three figures before the decimal point. The first or hundreds figure is discarded, the other figures giving the "Score" when properly pointed off by inspection. Discarding the 2 gives the "Score" figures of 35. Inspection shows there are more than .35 and less than 35, and thus the same result, 3.5, is obtained as by the previous method. Reversion Method. (a) Direct. The principle of reversion used in figuring the oyster score1 may also be applied in this method. Example continued: The+.01 c.c. tube and one of the+.1 c.c. tubes revert to the 1 c.c. column, leaving seven +.1 c.c. tubes out of twenty samples. This gives 35 per cent. of the .1 c.c. tubes positive or as before the "Score" 3.5 when pointed off. (b) Percentage. The same thing may be done from the percentage column above, i. e., 5 per cent. of the .01 c.c. and 5 per cent. of the 1 c.c. tubes revert to make the 90 per cent. of the 1 c.c. tubes up to 100 per cent., leaving 35 per cent. of the .1 c.c. tubes positive as before. Single Dilution Method.-Frequently determinations are made in one dilution only. In this case the "Percentage Positive" gives the "Score" as where several are used. Split Dilutions.-Where other "Dilutions" are used than the regular ones, the same methods can be applied by using the corresponding "Dilution" in the computation. CONCLUSION ARGUMENT The reason the above simple methods give the "Geometrical Mean" arises from the fact that the ordinary bacteriological dilution scale is in reality a logarithmic scale, and the average dilution is the average logarithm or the logarithm of the "Geometrical Mean." A vast amount of published bacteriological data to be considered at some other time proves that bacteriological results follow a logarithmic probability curve, from which it follows that the median value closely corresponds to the geometrical mean. It is equally probable, therefore that another sample would be greater as less than the geometrical mean. There is nothing in this principle to limit the application of the method, and by intelligent application it can be employed in interpreting all similar forms of data. FIELD LABORATORY, MILFORD, CONN. WILLIAM FIRTH WELLS PITTSBURGH MEETING OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE THE seventieth meeting of the American Association for the Advancement of Science was held in Pittsburgh, Pennsylvania, on December 28, 1917, to January 3, 1918. It seems to be a very general opinion of the members who attended that the meeting was practically an unqualified success. The total registration at the office of the permanent secretary was 692. It is impossible to estimate the number of members who were deterred from attendance by the statement sent to the press by the Pennsylvania Railroad late in December, and by the published letter of Dr. Richards, but it is obvious that no congestion of traffic, and no clogging of trains resulted from the meeting. Of the 692 persons registered, 194 came from Pittsburgh and other parts of Pennsylvania, 122 registering from Pittsburgh alone. The remaining attendance came as usual from all points of the compass, and were distributed on the regular trains arriving at different times, so that their train presence was scarcely to be noticed. The attendance was distributed as follows: from Pittsburgh and the rest of Pennsylvania, as just stated, 194, New York 84, Ohio 59, District of Columbia 44, Illinois 34, Massachusetts 26, West Virginia 21, Indiana 20, Michigan 18, Wisconsin 15, Maryland, Missouri and Canada 14 each, Iowa and Texas 13 each, New Jersey and Virginia 11 each, California 10, North Carolina 8, Connecticut, Tennessee and Kansas 6 each, Minnesota and Arizona 5 each, New Hampshire, Louisiana and Montana 4 each, Maine, Delaware and Kentucky 3 each, Japan, Nebraska, Utah, Oregon and Colorado 2 each, Rhode Island, Georgia, North Dakota, Arkansas and Wyoming 1 each. The interest of the meeting was enhanced by the presence of the following foreigners, who were made honorary associates for the meeting: Lieutenant Georgia Abbetti, of the Italian Military Commission; Lieutenant G. P. Thompson, of the Royal Flying Corps of Great Britain; Captain DeGuiche, of the French Military Commission, and Dr. Shigetaro Kawasaki, chief geologist of Korea. The impressive keynote of the whole meeting was war preparation and efficiency. This was borne out not only in a number of symposia devoted to specific war topics, but also in other discussions, and in other papers, the titles of which would not necessarily lead one to expect a development along the line of war preparation. The local press was keen in noticing this aspect of the meeting, and paid great attention to the papers of the entire session. The opening general session of the association was held Friday night, December 28, in the lecture hall of the Carnegie Institution. The president of the Association, Professor Theodore W. Richards, of Harvard University, was absent, and Dr. George H. Perkins, of the University of Vermont, senior vice-president, presided. Mr. H. M. Irons, city at torney of Pittsburgh, gave an address of welcome on behalf of the mayor of Pittsburgh, to which Dr. Perkins replied. The permanent secretary, under instructions from the council, proposed the following amendments to the constitution, which were adopted unanimously: 1. To amend Article 22 of the constitution by omitting after the word "chemistry'' in the second line, the words "including its application to agriculture and the arts." The article as amended will read: Sections and Sub-sections Art. 22. The Association shall be divided into sections, viz: A-Mathematics and Astronomy; BPhysics; C-Chemistry; D-Engineering; EGeology and Geography; F-Zoology; G-," etc. 2. To amend Article 9 of the constitution by adding in line 8, after the words "Permanent Secretary" the words "and the secretaries of the Sections." (Note. The effect of the above will be to make secretaries eligible for reelection.) The Article as amended will then read: "Art. 9. The officers of the association shall be elected by balloting by the General Committee from the fellows and shall consist of a president, a vice-president from each section, a permanent secretary, a treasurer, and a secretary from each section; that is, with the exception of the permanent secretary, the treasurer and the secretaries of the sections, shall be elected at each meeting for the following one and, with the exception of the treasurer and the permanent secretary and the secretaries of the sections, shall not be reelected for the next two meetings. The term of office of the permanent secretary and of the treasurer and of the secretaries of the sections shall be five years.' Dr. W. J. Holland, chairman of the local committee, made certain announcements, after which Dr. C. R. Van Hise, retiring president of the association, gave his address, which had for its title "Some Economic Aspects of the World War,'' and in this able and strong address President Van Hise set the note for the entire meeting. This was followed by a reception in the foyer of the Carnegie Institution by the members of the local committee and their wives. Certain special items on the program of the week may be especially mentioned on account of their war bearing. Section C held a symposium on "Education in Chemical Engineering." Section M held an important symposium on "Factors concerned in an Increased Agricultural Production." Section I listened to a paper by Hon. John Barrett on "The War and the New Pan-America," and before this same section, Howard E. Coffin, president of the Aircraft Board at Wash ington, spoke on the subject of "General Standardization."’ Section B held a general interest session on the subject of "Relationship of Physics to the War." Section G with the Botanical Society of America and the American Phytopathological Society, held a joint session on "War Problems in Botany." Dr. Vernon L. Kellogg, formerly of the Belgium Relief Commission, and now with Mr. Hoover's board in Washington, gave an exceedingly strong address before the Entomological Society of America on "The Biological Aspects of the War." Section I held a special symposium on "War Problems." Section F held a symposium on "Contributions of Zoology to Human Welfare," in which many war problems were discussed. Section K held a very important symposium which was packed to the doors, on the subject of "Medical Problems of the War." This symposium included an address by Lieutenant George Loewy, of the French Army, on "The Treatment of War Wounds by the Carrel Method," which was illustrated by moving pictures. The School Garden Association of America held a symposium on "Organization of War Gardens.'' The Association of Economic Entomologists discussed the two following topics at length: "Insects and Camp Sanitation," and "How the Entomologist can assist in increasing Food Production.'' The Botanical Society of America, and the American Phytopathological Society held a symposium on "Phytopathology in relation to War Service.'' Many of these papers will be published in subsequent issues of this journal, and abstracts of many more will also appear. The affiliated societies meeting with the association at Pittsburgh were as follows: American Federation of Teachers of Mathematical and Natural Sciences, American Physical Society, Optical Society of America, American Electrochemical Society, Society for the Promotion of Engineering Education, Paleontological Society of America, American Society of Naturalists, Entomological Society of America, American Association of Economic Entomologists, Ecological Society of America, Wilson Ornithological Club, Botanical Society of America, American Phytopathological Society, American Society for Horticultural Science, American Fern Society, American Microscopical Society, American Psychological Association, American Metric Association, American Nature Study Society, The School Garden Association of America, Society of American Foresters, Society of the Sigma Xi, Gamma Alpha Graduate Scientific Fraternity, Phi Kappa Phi Fraternity. The local arrangements for the meeting had been made in a very efficient manner by the local committee, of which Dr. W. J. Holland, of the Carnegie Museum, was chairman, and Dr. S. B. Linhart, of the University of Pittsburgh, was secretary. All the meetings were held in the buildings of the University of Pittsburgh, The Carnegie Institute of Technology and the Carnegie Institute. The council of the association took action as follows: 1. Resolved that the revision of the constitution be not pushed at this time-a report published. 2. Resolved that the dues of those members in active service in the army and navy be remitted for the period of the war when the member in question makes specific request in his own case. 3. Resolved that the editorial control of the journal SCIENCE be placed in the charge of an editorial committee to be named by the committee on policy. 4. Resolved that the necessary arrangements can be made at the Post Office Department so that the journal may be sent to the front in Europe by members who desire to do so. 5. Messrs. H. B. Ward, H. C. Cowles and Stewart Paton were elected members of the council. 6. The following were made life members emeritus under the terms of the Jane M. Smith Fund: C. H. Fernald, R. H. Richards, Marshall Calkins and T. J. W. Burgess. 7. Two hundred and seventy-eight fellows were elected from the nominations by especially appointed representatives of the sections who have scrutinized the manuscript list at Washington. 8. Resolved that until the next annual meeting, all business of the association be referred to the Committee on Policy with power to act. 9. Resolved that the president of the association be requested to appoint a committee of five fellows to cooperate with a similar committee of the Association of University Professors, and with other similar associations in the consideration of methods for the publication in this country of bibliographies progress-reports and abstracts. 10. On motion, the council instructed the permanent secretary to carry into effect the following points at future annual meetings: (a) The meeting places for sections and societies having been once printed, should not be changed. (b) Meeting places for allied interests and societies should be placed as close together as possible. (c) The entire number of meeting places should be grouped as closely as possible. (d) Authorizing the printing of detailed advice to Local Committee for individual distribution to members of such committee. 11. Messrs. Stewart Paton, H. L. Fairchild and H. B. Ward were elected members of the comImittee on policy. 12. The permanent secretary was granted the authority to purchase a new electric addressograph for his office. 13. The salary of the assistant secretary, Mr. F. S. Hazard, was raised to $2,100 per annum, beginning with January 1, 1918. 14. The council endorsed the following resolution coming from Section F: "It is important that in any plans formulated or encouraged by the American Association for the Advancement of Science looking towards the organization and development of national or international bibliographic projects, the existing international bibliographic undertaking for zoology, i. e., the Concilium Bibliographicum in Zurich, long approved by this association and in part supported by numerous grants from its funds, be kept definitely in mind and included in any plan for bibliographic work presented for consideration by the special committee of the council.'' At the meeting of the general committee at the Schenley Hotel on the night of December 31, it was decided to hold the next meeting of the association in Boston, Massachusetts, meeting to begin on Friday, December 27, 1918. This decision was adopted with the amendment that the committee on policy be given the power to cancel the meeting, or to change the place for it should they see best to do so. On motion the general committee recommended to the general committee of 1918 that St. Louis be chosen for the place of meeting following Boston. The following officers were elected, President, John M. Coulter, of the University of Chicago; Vice-presidents as follows: Section A, George D. Burkhoff, Harvard University; B, Gordon T. Hull, Dartmouth College; E, David White, U. S. Geological Survey, F, Wm. Patten, Dartmouth College; I, John Barrett, Washington; K, Frederic S. Lee, Columbia University; M, H. P. Armsby, Pennsylvania State College. O. E. Jennings, of the Carnegie Museum, Pittsburgh, was elected general secretary for 1918. The following secretaries of sections were then elected: Section A, F. R. Moulton, University of Chicago; C, Arthur A. Blanchard, Massachusetts Institute of Technology; D, F. L. Bishop, University of Pittsburgh; G, Mel. T. Cook, Rutgers College; L. O. HOWARD, |