faculty to volunteer for service at the outbreak of the war, joining the New York Engineer Corps.

PROFESSOR A. L. DANIELS, Williams professor of mathematics in the University of Vermont, died on July 18, aged sixty-nine years. He was made professor emeritus, on the Carnegie Foundation, in 1914, after a service of twentynine years.

DR. E. W. SANFORD, of the Johns Hopkins University faculty, has died in Centerville, Conn., from blood poisoning produced by accidental inoculation while engaged in research work for the government.

DR. LUDWIG EDINGER, director of the Neurologic Institute of Frankfort-on-Main, known for his work in the comparative anatomy of the nervous system, has died at the age of sixty-three years.

THE death is announced of Dr. Régis, professor of mental diseases at Bordeaux.

DR. MIGUEL SANCHEZ-TOLEDO, professor of physiology at the University of Havana, died on July 13.

GIFTS to the Brooklyn Institute of Arts and Sciences amounting to $70,000 were reported at the June meeting of the board of trustees. Of this amount $60,000 was given by Mr. Samuel P. Avery for the endowment of the Institute's department of education, and $10,000 by two unnamed donors for the endowment of the Brooklyn Botanic Garden, a division of the institute. The terms of the Botanic Garden gift stipulate that it shall be known permanently as the "Benjamin Stuart Gager Fund," in memory of Director Gager's little son who died last spring.

THE Bureau of Oil Conservation, Oil Division, U. S. Fuel Administration, is desirous of securing a combustion engineer for each of the following districts, who will act as an inspector visiting all plants within his district using fuel oil and natural gas: Boston, Providence, New York City, Philadelphia, Pittsburgh, Buffalo, Detroit, Chicago, Minneapolis, Tulsa, New Orleans and San Francisco. It is desirable that these men should act as

volunteers where possible, but the Administration is prepared to pay a reasonable compensation for men who can not afford to give their services to the government. Only men who have had experience in fuel oil and natural gas combustion would be of value.

AN editorial note in Nature asks: "Is the Carnegie Trust for the Universities of Scotland doing its duty in strengthening and developing scientific study and research? That is the question suggested by the report of a special committee published in the December

number of the Journal of the British Science Guild. The question was first raised in an incisive manner by Professor Soddy in an article communicated to Science Progress (January, 1917), and further inquiry seems to show that his contention is well founded. There may be some difference of opinion as to the exact interpretation of Clause A of the Trust Constitution; but there can be no doubt that the main object of the trust is to foster science, pure and applied, in all its branches, and to strengthen that side of university education which is of direct technical or commercial value. In the light of that general principle the following facts are well worthy of careful consideration: (1) Only 14 per cent. of the available funds have been expended on scientific research; (2) by endowment out of Carnegie Funds of certain scientific departments, money formerly spent in their maintenance has been diverted into other channls, so that the university on its scientific side has not really been strengthened; (3) among the twenty-two members of the board of trustees, there have never been more, and have usually been fewer, than four who could be regarded as representing science, the majority being practically ignorant of the methods, and even the meaning, of research."

UNIVERSITY AND EDUCATIONAL NEWS

THE University of London has received a bequest of £2,000 for the engineering faculty of King's College under the will of Lieutenant R. C. Hodson, a former student in the enginering department of the college, who was

killed in France last year, and a donation of £51 from Miss Gertrude Jones for the purposes of the Galton Laboratory at University College.

PRESIDENT J. G. SCHURMAN, of Cornell University, has received leave of absence from the university until next October and will devote the summer to patriotic work in France. During his absence, Professor Dexter S. Kimball, acting dean of Sibley College, is, by appointment of the board of trustees, acting president of the university.

AT the University of Minnesota Professor H. H. Kildee has resigned as professor and chief of the dairy husbandry division in order to become head of the department of animal industry at the State College of Iowa at Ames; G. E. Weaver and H. R. Searles have resigned as assistant professor and intructor, respectively, of dairy husbandry to enter government service with the marines; Miss Josephine T. Berry has resigned as professor of nutrition and chief of the Division of Home Economics in order to continue her work as assistant director for home economics of the Federal Board for Vocational Education; Miss Mildred Weigley who has been associate professor and acting chief during Miss Berry's leave of absence has been promoted to the position made vacant by Miss Berry's resignation. I. D. Charlton has resigned as professor and chief of the Division of Farm Engineering in order to enter war service; J. S. Montgomery has resigned his position as associate professor of animal husbandry in charge of the section of horse husbandry in order to accept a position with a large stock breeder.

MR. A. M. CHICKERING, instructor in biology in Beloit College for several years, has been elected to the professorship of biology in Albion College and will assume his new duties with the opening of college in September.

MISS ALICE M. BORING has resigned as associate professor of zoology at the University of Maine and received an appointment in the premedical department of the Peking Union. Medical College, China.

DR. SETH LAKE STRONG, who was graduated from the Harvard Medical School in the class of 1913, has been appointed lecturer in surgery to the Royal Medical College at Bangkok, Siam, and will also act as surgeon to the Siravaj Hospital there.

CAPTAIN M. J. STEWART has been elected professor of pathology and bacteriology in the University of Leeds. He received his commission in 1915 and has served as pathologist to the East Leeds War Hospital, and in a similar capacity in France. A few months ago he was recalled to Leeds and undertook the acting headship of the department of pathology and bacteriology.

THE following appointments are announced in the geological sciences in Germany and Austria: Professor W. Branca has retired from his professorship in Berlin, and has been succeeded by Professor J. Pompecki, of Tübingen. Professor E. Kayser has similarly retired in Marburg, and his successor is Professor R. Wedekind. Professor L. Milch, of Greifswald, has followed the late Professor Hintze as professor of mineralogy in Breslau, and Professor E. Hennig, of Berlin, has become professor of geology at Tübingen. Professor O. Abel has been made professor of paleobiology in Vienna.

DISCUSSION AND CORRESPONDENCE

FORMATIVE SETTING OF LACCOLITHIC
MOUNTAINS

ALTHOUGH the simple "Blister" hypothesis of laccolithic intrusion, which was for the first time proposed for the Henry Mountains in southern Utah, finds so few supporters, of late little is done towards arriving at a better solution. Perusal of the descriptions of the Henry Mountains soon discloses the fact that not all of their story is yet told. There is nowhere any suggestion of relationships possibly existing between the local tectonics and

the intrusive structures. Without these the phenomenon seems, as has been so often urged, a mechanical impossibility. This is the view which most Europeans take. In consequence they frequently confound laccolithic structure with that presented by denuded volcanic necks.

A number of facts militates strongly against the Henry Mountains explanation of loccolithic protuberance. Three basic premises appear wholly untenable. Most vitiating is the seeming incompetency of simple hydrostatic pressure to produce the desired results. Inadequacy of relative lithologic density is now commonly conceded. There also appears to be a radical disparity between the physical conditions accompanying the formation of laccoliths and their once supposed nearest kin the sills.

On the other hand the recent unearthing of the infrabasal make-up of certain laccoliths clearly points to a fundamental dependence of this class of mountains upon prior geologic structure. The shape of laccolithic masses is found to be cuneiform instead of lenticular; and thus at once does away with the blister idea. Quite essential appears to be the presence of crustal lines of weakness. The magmatic swelling or localization of laccoliths is discovered to be a direct function of orographic potentialities.

In seeking an immediate cause for his laccolithic intrusion Professor Gilbert did not lose sight of certain mechanical shortcomings of his explanation. These he sought to overcome by appealing to certain associated factors, which, however, later, Doctor Cross showed to be both unnecessary and not demonstrated as such. Professor J. D. Dana got over the difficulties by brushing aside all considerations except simple hydrostatic pressure and with this feature alone regarded the Gilbertian hypothesis complete. This is doubtless one of the main reasons why from a mechanical angle leading European geologists have so persistently challenged the American view of laccolithic intrusion. At the same time Old World writers on the theme offer no alternative theory to take the place of the one which they seek to discredit. Through the results of close inspection of certain laccoliths of northern New Mexico the chief objections which were raised against the Gilbert view seem to be fully met. Controlling tectonic factors which all describers of laccoliths have

missed thus appear to supply the long sought desiderata.

As a primary consideration in order that a laccolith be produced rather than any other form of volcanic manifestation it appears that the intrusive mass shall have a particular tectonic setting. Profound faulting is one of these prime factors. Another is orographic flexing by which the rigidity of certain arching strata largely maintains the load of superincumbent materials. Probably the high viscosity of acidic magmas has an important but as yet uncalculated influence on events. The remarkable infrabasal structure which the New Mexico laccoliths reveal carries the inquiry a step more remote and explains the deep-seated cause of the major faulting, whereby an orographic prism is sustained by a sharp Pre-Cambrian arch, the rigidity of which is not even yet lost although the adjoining blocks on either side are allowed to slide down, as it were, the steep sides of the old flexure.

Now at the southern terminus of the Rocky Mountain Cordillera, in northern New Mexico, there is a succession of open flexures, the amplitude of which grows less as they recede from the main axis. It is where these folds cross great fault lines that laccoliths form. Thus through direct mathematical analysis of the tectonic problems presented and in the satisfaction of the most urgent tectonic demands an adequate raison d'être for laccolithic genesis and location seems to be offered.

CHARLES KEYES

SOIL REACTION AND THE PRESENCE OF AZOTOBACTER

DURING the summer of 1917 the writer conducted a preliminary survey of local soils to ascertain the relative nitrogen-fixing ability and prevalence of Azotobacter. Ninety soils were collected within two miles of the laboratory. The samples were taken from as widely varying soil conditions as could be located including the following: cultivated, permanent alfalfa, bluegrass sod, native pasture, barren hilltops, river bottom, sand bar, roadside and forest.

When cultured in a standard alkaline mannite solution 41 per cent. of the soils failed to show any Azotobacter growth. The average nitrogen fixed, per 100 c.c. cultural solution, in such cultures was 7.76 mg. The average nitrogen fixed in cultures showing Azotobacter was 16.22 mg. per 100 c.c. cultural solution.

A study of the reaction of these soils gave very interesting results. The hydrogen ion concentration of an aqueous extract of the soils was measured by the colorimetric method outlined by Clark and Lubs.1

The range of hydrogen ion concentration in the soil extracts, prepared by shaking one part of soil with one part of water and centrifuging expressed in PH was from 5.3 to 7.8. All of the extracts from soils which developed Azotobacter, with the exception of three, gave a P of 6.0 or above. All of those which failed to give Azotobacter, with the exception of three, gave a P of 5.9 or less. These results would indicate that the absolute reaction is probably the major factor controlling the presence of Azotobacter in soils.

H

Н

P. L. GAINEY RESEARCH LABORATORY IN SOIL BACTERIOLOGY, KANSAS AGRICULTURAL EXPER. STA.

DESIGNATION OF SPECIALIZING PHYSICISTS

PHYSICISTS specializing along certain definite lines in such a way or to such a degree that the broad term physicist is not sufficiently descriptive of their professional activities, are frequently at a loss for a suitable designation. For example, a physicist engaged in industrial physics along the lines of electricity may not consider himself an electrical engineer, and still less an "electrician" in the ordinarily accepted use of the term. What shall he call himself? A physicist specializing in mechanics may be neither a mechanical engineer nor a mechanic or mechanician. Similarly one specializing in heat may not be a heating engineer, and one in light may be no optician. The specialist in sound who is now coming into recognition more and more has not even the restricted range of choice given to the others cited.

1 Journal of Bacteriology, Vol. 2, Nos. 1, 2 and 3.