MR. L. O. HOWARD, consulting engineer of Salt Lake City, has been appointed dean of the School of Mines of the State College of Washington at Pullman.

AT the Stevens Institute of Technology, L. A. Hazeltine has succeeded the late Professor Ganz as acting professor of electrical engineering in charge of the department.

JAMES H. ELLIS, research associate in physical chemistry at Throop College of Technology, Pasadena, Cal., has become a member of the physics department of the college as instructor in electrical measurements.

MR. I. L. MILLER, of Indiana University, has been appointed professor of mathematics in Carthage College.

PROFESSOR A. S. LEYTON has resigned the chair of pathology and bacteriology of the University of Leeds.

DISCUSSION AND CORRESPONDENCE SOCIEDAD CIENTÍFICA ANTONIO ALZATE For those who have been led by a perusal of the daily papers to suppose that Mexico was in a progressive state of disorganization, the recent issues of the "Memorias" of the "Sociedad Científica Antonio Alzate," of Mexico City, will afford good proof that their hasty judgment had been erroneous.

The thirty-sixth volume of the Memorias of this Society, which has just appeared, and comprises 740 pages of text with 82 plates, is entirely devoted to a monograph on the State of Puebla by Señor Enrique Juan Palacios.1 His study falls into three main sections, the first of which regards the ethnology, geology and climatology of the state, the second, its flora and fauna, its industries, its mineral resources, and its commerce and means of communication; the third section treats of the political divisions of the state, and of its

1''Memorias y Rivista de la Sociedad Científica Antonio Alzate,'' published under the direction of the perpetual secretary, Rafael Aguilar y Santillan, Tomo 36, 2 parts, Mexico, June, 1917. 740 pp., 82 plts., 8°, "Puebla, su territorio y sus habitantes,'' by Enrique Juan Palacios.

history, embracing a description of its principal communities, chief among which is of course the city of Puebla, consisting of about 100,000 inhabitants.

The area of the state is given by the writer as 33,653 square kilometers, or about 14,000 square miles, and its population as nearly 1,100,000, showing a density of nearly 80 to the square mile. In population it ranks third among the Mexican states. The white race numbers 86,000, the population of mixed race 826,000 (three quarters of the whole), and the Indians, nearly 200,000. Within its territory is the highest peak in North America, with the exception of Mount McKinley. This is the mountain bearing the Indian name Citlaltépal, or "Smoking Mountain," though often called Orizaba. It rises to a height of 5,675 meters, or 18,614 feet, and is an extinct, or at least an inactive volcano.

The fossil remains found in the state of Puebla are of considerable importance. Among them are bones of Elephas Columbi Falconer, found at San Jeronimo, in the district of Tehuacán, and also in the region about the city of Puebla. Within the limits of its municipality, at Molino de Santa Barbara, fossil elephant tusks have been unearthed; mastodon tusks have also been discovered in the state, as well as teeth of Elephas primigenius (pp. 54, 55).

Ample space has been devoted to the mineral resources of Puebla and to their exploitation. While the principal interests of the state are agricultural and industrial, there were, according to the statistical report of 1907, as many as 29 mines then in operation (copper, iron, gold, silver and lead), the number of persons employed being 1,068; the production was valued at 1,168,428 Mexican dollars. Most of these mines must have been small undertakings, since Southworth in his Mining Directory for 1908 only notes three mines as in active operation, that of San Lucas (gold and silver) in the district of Tehuacan; that of Tetala, an English company organized in 1904, with a capital of £100,000, and the mine "La Aurora" of Tezuitlan, an enterprise dating from 1905,

and having resources put at 10,000,000 Mexican dollars.

Of what might be called precious-stone material there is very little signalized; some opal is found at Tecali and Tlatlauqui, and azurite occurs in Acatlan. The so-called "Mexican Onyx" (an aragonite) of the district of Tecali in the state of Puebla is well known, and was already used by the Aztecs for ornamental purposes.

In the State College in Puebla, where courses of law, medicine and engineering are given, besides the customary preparatory studies, there are excellent collections illustrating physics, chemistry, bacteriology and histology, and also radiographic and radioscopic installations, as well as apparatus for wireless telegraphy. There is also a well-furnished natural history collection and an important

museum.

The few items presented here may give a little idea of the quality of this monograph, though insufficient to indicate the wide field it so ably covers. It certainly merits to be consulted by all who are seeking information regarding one of the principal states of the Mexican Federation. GEORGE F. Kunz

NEW YORK CITY

THE TALKING MACHINE AND THE
PHONOGRAPH

TO THE EDITOR OF SCIENCE: Professor Peckham's interesting account of the talking machine, as distinguished from the phonograph, in SCIENCE of November 9, closes with this statement:

It is not probable that any one had thought of a phonograph in the sense in which we use the term as early as 1772. Knowledge of electricity was not sufficiently advanced at that time.

This, I presume, is a mere slip of the pen, the writer thinking perhaps of the telephone while writing of the talking machine and the phonograph. Otherwise some of us who are engaged in other fields of science, and hence can lay claim to no special knowledge of physics, would like to have pointed out to us the connection between electricity and the ubiquitous phonograph.

J. VOLNEY LEWIS

SCIENTIFIC BOOKS

Mental Adjustments. By FREDERICK LYMAN WELLS, Ph.D. New York & London: D. Appleton & Co., 1917.

F. L. Wells wrote his book with a rather unusual background. Trained in the experimental school of Cattell and Woodworth, Wells took up his work at the McLean Hospital in 1907, where he returned after one year's work with Dr. August Hoch on Ward's Island and with considerable contact with Dr. Charles Macfie Campbell, to whom the book is dedicated. Coming from a school which might be frankly dynamic and objective, if it had the necessary philosophical courage combined with a desire for consistency, Wells found most valuable opportunities at the McLean Hospital owing to the excellent tradition established there by Dr. Hoch in the study of an uncommonly interesting type of patients; and even before he went to Ward's Island he had been concerned with association experiments and with problems which were bound to bring him into touch with the sphere of ideas of Freud and Jung. His studies of the last few years have shown a growing mastery of the psychopathological problems and the present book gives ample evidence of earnest and able collaboration along lines very characteristic of modern American psychopathology.

The

Eight chapters constitute this book of 331 pages. In "Mental Adaptation" he gives illustrations of types and problems of adaptation and in a way a forecast of the book. discussion of "Use and waste in thought and conduct" leads the reader, in one of the best organized chapters of the book, to a very direct understanding of fundamental adaptive trends and their adjustments and supplements, many times crossing the boundary between the motor" and "mental" varieties of behavior, "granting, indeed, that such a boundary exists." He gives a very good picture of the rôle of fancy and autistic thinking (i. e., primitive fancy unconcerned about reality) and especially of the rôle of word-plays and of rationalization. He sums up the discussion by saying that "realistic thinking contributes mainly to making it possible to exist, and

autistic thinking to making it worth while to live."

Pages 71 to 113 are devoted to Symbolic Association, in a chapter showing a remarkably wide range of resources of reading, and leading from the symbolisms of language and of normal waking life to those of dreams.

66

The discussion of emotion is given the title "The continuity of emotion," and deals with "affective displacement" (a somewhat questionable term for affective diffusion and disproportions) and affective compensation. The more specific types of "affective displacement" are exemplified by a number of unaccountable" dislikes and in the use of contrast and exaggeration in humor. "Loaded" experiences and transference are reduced to the principle that emotions are to be viewed as reactions, which are switched in and out according to the principle of associated reflex and conditioned and associated responses. The switching off of the affect is spoken of as a deemotionalizing and siphoning process. rôle of various complexes and affective symbolism is illustrated by many examples. The phrase "Objekt vergeht, Affect besteht" expresses the meaning of the title of the chapter.

The

The discussion of "Types of Dissociation" is more clearly systematic than most of the rest of the book and is a valuable survey for the student, although perhaps somewhat heavily loaded with varieties and subvarieties for those readers who have but little concrete experience, and who might have a desire for principles rather than for details. Chapter VI. (pp. 204-226) takes up the dynamic importance of factors which determine repressions and its various degrees. Chapter VII. takes us into the field of available experimental approaches, with a discussion of various types of intelligence tests, the association method, and those involving what is called measurements by relative position (the "better or worse"), free association, the schedule of personality study; and a final chapter dealing with "Balancing Factors" gives a valuation of various trends for life and the quest of happiness and application to education.

It is, I suppose, both a merit and a draw

back of the book that it resists a brief summarizing survey. Clearness of principles and the ease of reading might readily gain by moderation in the amount of illustration and in the use of metaphors, or, since most of these are really well chosen, by paragraphs of orientation. The few paragraphs of this character certainly do much to make one more receptive.

Wells puts forth as his aim not to tell us things, but to enable us to see for ourselves what we would otherwise miss. He does, in fact, tell us so many things that one feels very much the importance of what he himself calls "strategic regrouping," of the author's treasure of reading and of observation. Every reader of the replete volume must be willing to do his share; those who do so will certainly find a rich material and ample work. How readily the book would lead one not already experienced in the field will have to be tried out. The reviewer can not help feeling that medical responsibilities with the cases and the material might have added a kind of practical simplicity and directness where the reader might be apt to lose himself in the detail. Wells does, however, make it clear that the normal and the abnormal are made of much the same material, and his book, with its softened rendering of Freudian conceptions, will be a stimulus and a help along sane and useful lines. ADOLF MEYER

The Combination of Observations. By David BRUNT, M.A. (Cantab.), B.Sc. (Wales), Lecturer in Mathematics at the Monmouthshire Training College, Carleon, Mon. Cambridge University Press. 1917. Pp. x+

219.

This book gives an elementary treatment of the methods of adjusting observations. The normal or Gaussian law of error is derived from Hagan's hypotheses regarding the nature of errors, and the presentation in this connec tion is very attractive. The book gives a brief and simple treatment of certain important parts of the theory of statistics. This includes Pearson's generalized frequency curves first published in the Philosophical Transactions of

the Royal Society, 186 A, p. 343. These curves include six types besides the normal curve, but the book makes no reference to the five additional types of curves recently published by Pearson.1 The book presents a treatment of the correlation of two systems of variates. The treatment is, in general, clear, and should serve a useful purpose in making better known to persons who are applying these methods to data the nature of some of the limitations that underlie the interpretations of correlation coefficients. However, the reviewer has one criticism to offer. On p. 155, using r for the correlation coefficient, we are told that "it seems doubtful whether any serious meaning can be attached to values of r which are less than .5." It seems to the reviewer that this statement should be modified. To be sure, the statement would hold if the correlation coefficient r were calculated from such a small number of observations that the probable error of r is not particularly small compared to r. But when the conditions under which the formula for probable error of r is derived are well satisfied, r may be much smaller than 0.5 and have decided significance if derived from large enough number of observations to make its probable error small in comparison to the value of r.

A useful chapter is devoted to harmonic analysis from the standpoint of least squares, including an interesting section on a practical method of investigating periodicities. The last chapter deals with the periodogram, including a treatment of hidden periodicities. H. L. RIETZ

UNIVERSITY OF ILLINOIS

SPECIAL ARTICLES

THE PRODUCTION OF GASEOUS IONS AND THEIR RECOMBINATION

GASEOUS ionization has played a large part in recent advances in both physics and chemistry.

In the ordinary college- and high-school courses given in these subjects little, if any, attempt is made, however, to demonstrate methods of producing gaseous ions or of measuring their recombination or diffusion con1 Phil. Trans., 216 A, p. 429.

stants. Practically no laboratory work along these lines by elementary students is attempted. This may be explained in part by the fact that most investigators in this field of research have made use of the electrometer, an instrument well adapted for demonstration purposes but inappropriate for use by the inexperienced student. An electroscope of very simple design has, however, proved entirely satisfactory in place of the more cumbersome and possibly less sensitive electrometer.

Some elementary experiments are suggested in the first part of this paper using apparatus involving little or no expense and which may be assembled by any high-school student. This is followed by a description of some results obtained in verification of the law governing the recombination of the ions of a gas.

A brass rod passes through a sulphur plug into the hollow cylindrical chamber (C) 12 cm. high and of 4 cm. radius. On this rod is mounted a flat brass strip which supports the gold leaf. The top of this mounting projects through a large opening in the square metal box surrounding the gold leaf to permit the electroscope to be charged by removing the metal cap (D). (B) is a brass tube approximately 2 meters long the radius of which will depend upon the laboratory facilities for providing a suitable current of gas. If air ionization is to be studied and compressed air is not available, a suction pump attached to a water faucet will provide a convenient velocity for carrying ionized air through (B) if its radius is of approximately 3 cm. diameter.

The velocity of the ions and consequently the time taken for their passage over a given distance may be obtained by measuring the volume of air passing in a given time. A common gas meter (M) provided with a dial one turn of which registered one half of a cubic foot was used in these experiments. The air passing through the tube may be dried by calcium chloride and ions prevented from entering with the air stream by a plug of cotton wool placed at (E). Lead screens (S) should be erected to shield the electroscope from direct radiation. Provided radium salt be used as ionizing agent at a short distance from the electroscope, these screens will need to be several centimeters thick.

The gas passing through the tube may be ionized by X-rays or Y-rays shot through a slit (R) cut in the tube and covered by a thin mica sheet, or the ionizing source may be placed inside the tube. A 2 or 3 mm. spark between the secondaries of an induction coil sealed into the tube provides a convenient source of ionization for demonstration purposes. X-rays also produce powerful ionization effects. A 2-inch X-ray bulb run at dull luminescence by a coil capable of producing a 4 cm. spark will provide sufficient ionization for the experiments described below.

A Nernst lamp is more suitable for projecting the gold leaf on a screen than the ordinary lantern. For laboratory work a low powered microscope with a divided scale in the eye piece is used for measuring the rate of fall of the gold leaf.

An electroscope of the type shown in Fig. 1 may be made of comparatively small capacity. If the leaf be charged to a relatively high potential, it becomes an instrument of high sensibility. Owing to the extremely small mass of the gold leaf it will rapidly alter its rate of deflection as the number of ions swept into the chamber changes.

Place the X-ray bulb directly over the electroscope and charge the gold leaf, by means of an ebonite rod, till it shows large divergence. Run the bulb for an instant and the gold leaf at once drops a distance proportional to the ionization produced in the electroscope by di

rect radiation. If the charging cap is not replaced before starting the bulb, the sudden drop takes place as before, but the leaf instead of stopping its motion as suddenly as it began gradually slows up with time. This effect is produced by the ions in the air surrounding the electroscope rapidly diffusing into it, the number diminishing as recombination takes place. Some idea of the rapidity with which the leaf comes to rest may be obtained from Table I. The numbers represent readings on the scale between the intervals stated in the first column. The readings with 3 second intervals were observed and recorded without assistance. Shorter intervals required assistance in making the record.

Place the X-ray bulb over the slit as indicated in Fig. 1 and start the suction pump. When the radiation passes through the slit large quantities of positive and negative ions are produced in the air stream directly beneath. If the bulb is but a short distance from the electroscope and the air velocity is high, a large proportion of the ions originally produced will be swept into the chamber causing a rapid rate of fall of the gold leaf. The remainder have either recombined or diffused to the side of the tube. Since the negative ions diffuse more rapidly than the positive, the