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hemoglobin fixes carbon monoxide and in all probability a relatively large part of aerial CO is disposed of in this way. The hemoglobin binding CO is destroyed in the liver, the CO probably remaining attached to the protein end of the globin, and not to the biliary and urinary pigment which result from the decomposition of hemoglobin. The globin is excreted as urea, ammonia, etc., while some may be retained as amino-acid, but doubtless the CO globin is treated as foreign material and excreted. Another method of disposal of aerial carbon monoxide is the union in sunlight, with the halogens, bromine, iodine, etc., of our atmosphere and with the fluorine freed in the mountainous districts during storms involving lightning. In such cases, the carbon monoxide is converted to a carbonyl halide or to CO2, in either case being capable of utilization by bacteria, plants with chlorophyll, etc.
The above communication was written previously to the publication of Lamb, Bray and Frazer's contribution from The Chemical Warfare Service entitled "The removal of carbon monoxide from the air" in the J. Ind. and Engineering Chemistry, March 1920, Vol. 12, p. 213. W. M.
THE ATTAINMENT OF HIGH LEVELS IN THE ATMOSPHERE
TO THE EDITOR OF SCIENCE: In the April 9, 1920, issue of SCIENCE, Dr. J. G. Coffin, on behalf of the Curtiss Aeronautical and Motor Corporation, questions the record of Major Schroeder, namely 36,020 feet, given in my brief review of high level records, in SCIENCE, March 19, 1920.
So far as I can now ascertain, Dr. Coffin is justified in questioning this particular record. The director of the Bureau of Standards informs me that the bureau has not yet determined the true altitude and that when determined it will be for the Air Service to make proper announcement. With such imperfect data, as I can now obtain, the approximate values are: Rohlfs, 9880.5 meters (32,418 feet); Schroeder, 9505.0 meters (31,184 feet). These are the elevations corrected for mean air column temperature, vapor pressure, gravity, alti
tude and latitude. The main reduction factor is of course the temperature. These results, however, must not be accepted as final. Until final and authentic data are forthcoming, the justice of Dr. Coffin's criticism must be admitted. The words "The record now standsSchroeder, February 27, 1920, 10,979 meters" in SCIENCE, No. 1316, p. 288, should be accepted with reservation.
Let us hope, however, that before the end of summer both of these plucky aviators will have attained a true height of 10,000 meters.
BLUE HILL OBSERVATORY, April 22
Introduction to General Chemistry. By HERBERT N. McCOY AND ETHEL M. TERRY. Chicago, Ill., 1919. Pp. viii+605.
The subject matter covered in the course in chemistry given to the freshmen class at the University of Chicago is the basis for this text-book. It does not aim to include all the material usually considered in a course in descriptive inorganic chemistry; the facts of the science are used primarily to illustrate fundamental principles and laws. A brief statement of the order in which the material is treated will bring out the point of view of the authors. The first chapter deals with the measurement of gases. In the next four chapters the fundamental concepts of the science are developed; these include indestructibility of matter, a pure substance, an element, analysis of substances, law of definite composition derivation of formulæ. Acids, bases, and salts, water and solutions, the kinetic theory and the atomic hypothesis are next considered. A chapter on chlorine and its compounds with hydrogen and metals is followed by a consideration of chemical equilibrium, oxidation and reduction, heat and energy. Three chapters are devoted to the ionic hypothesis and one to electro-chemistry. Nitrogen, phosphorus, sulphur and carbon and their simple compounds are then described. A rather long chapter on organic chemistry in which structural formulæ are
freely used follows. Attention is next turned to the theory of dilute solutions, disperse systems, some additional elements, the periodic classification, and radio-activity.
In the discussion of the topics noted many chemical facts are brought before the student but stress is laid on principles and little space devoted to facts of general interest unless they serve as examples of these principles. For example, the only reference to the preparation of iron from its ores is a paragraph on carbon as a reducing agent, in which the statement is made that metallic iron is made from the mineral hematite by reduction with coke at white heat.
The book is clearly written. It will be of interest to teachers to see how rather difficult subjects can be handled effectively in a simple manner. It will be looked upon with favor as a text for beginners by those who desire to teach facts only through the use of laws and theories and do not think it advisable to unduly emphasize the applications of the science.
JAMES F. NORRIS
NOTES ON METEOROLOGY AND
RAINFALL INTERCEPTION BY TREES AND CROPS
FOR several years Mr. Robert E. Horton, consulting hydraulic engineer, Voorheesville, N. Y., has carried on investigations of the various aspects of rainfall in relation to runoff. In such studies what the hydraulic engineer needs to know first is how much rainfall reaches the ground, over a watershed. Is it the amount of precipitation that as shown by well-exposed gages ?2 No. Much rain and snow is intercepted by trees, and evaporated.
1 See "Additional Meteorological Data Needed by Engineers,' by R. E. Horton, Engineering News Record, March 27, 1919, pp. 614-616; reprinted in Monthly Weather Review, May, 1919, Vol. 47, pp. 305–307.
2 See "The Measurement of Rainfall and Snow," by R. E. Horton, Jour. New England Water Works Assoc., 1919, Vol. 33, pp. 14-71, 21 figs., 12 tables; reviewed in Monthly Weather Rev., May, 1919, Vol. 47, pp. 294–296.
Thus the hydraulic engineer, unlike the meteorologist, needs to study the catches of rain-gages under trees as well as in the open. [Some cooperative observers seem to have anticipated this need.] Mr. Horton has made a careful study of the amount of precipitation which falls through different kinds of trees and of that portion of the intercepted rainfall which runs down the trunks. Also, in order to enable him to form an estimate of the water which reaches the ground over a varied watershed he has determined the amount of rainfall intercepted by different growing crops in various stages. The results of his investigations have been published in the Monthly Weather Review.3
Mr. Horton concludes that
Rainfall interception represents a loss of precipitation which would otherwise be available to the soil. The loss takes place through evaporative processes, but may, for convenience be subdivided into (a) interception storage, and (b) evaporation during rain.
The amount of interception loss is primarily a function of the storage capacity of the plant surface, the duration of precipitation, and the evaporation rate during precipitation. Since there is generally a fairly close correlation between shower duration and amount of precipitation, estimates of interception loss can, for practical purposes, be expressed in terms of precipitation amount per shower.
The interception storage loss for trees varies from 0.02 to 0.07 inch per shower, and approaches these values for well-developed crops. The... loss is greater in light than in heavy showers, ranging from nearly 100 per cent. where the total rainfall does not exceed the interception storage capacity to about 25 per cent. as an average constant rate for most trees in heavy rains of long duration. [Of this] the amount of water reaching the ground by running down the trunks of trees is... commonly 1 to 5 per cent. of the total precipitation. The percentage increases from zero in light showers to a maximum constant percentage in heavy showers of long duration. Light showers are much more frequent than heavy ones, and the interception loss for a given precipitation in a month or season varies largely according to the rainfall distribution.
3 September, 1919, Vol. 47, pp. 603-623, 17 figs.
Expressing the interception loss in terms of depth on the horizontal projected area shadowed by the vegetation, the loss per shower of a given amount is very nearly the same for various broadleaved trees during the summer season. . . . The interception loss from needle-leaved trees, such as pines and hemlocks, is greater both as regards interception storage and evaporation during rain than from broad-leaved trees.
Data are insufficient for a final determination of the relative losses from trees in winter and in summer. Apparently the winter and summer losses for a given monthly precipitation for needleleaved trees the winter interception loss appears to be about 50 per cent. as great when the trees are defoliated as during the growing season. The average interception loss from 11 trees . . . during the summer of 1918 was 40 per cent. of the precipitation.
ATMOSPHERIC MOISTURE IN THE UNITED STATES
Three years ago, Mr. P. C. Day, chief of the climatological division of the Weather Bureau, published a monograph on "Relative humidities and vapor pressures over the United States, including a discussion of data from recording hair hygrometers," and to which recently Mr. W. J. Bennett, of Tampa, Florida, has added an interesting discussion of tables prepared along similar lines for Tampa. The diurnal changes in relative humidity (which is the water vapor present in the air divided by the maximum which would be possible at the temperature) are practically the opposite of the temperature changes, there being a change generally of 3 to 4 per cent. for each change of 1° C. in temperature.
Vapor pressure (the pressure exerted by the water vapor locally in the air) is a direct index of the absolute humidity (water vapor per unit volume of space). In summer in dry climates, such as at Boise, Idaho, the vapor pressure rises during the few hours immediately after sunrise as the moisture from the surface (e. g., dew) is evaporated. Then after
4 Monthly Weather Review, Suppl. No. 6, 1917, 61 pp. (mostly tables), 34 charts. Cf. review in Geogr. Rev., February, 1918, Vol. 5, pp. 155–156.
Monthly Weather Review, July and October, 1919, Vol. 47, pp. 466-468, 710, 2 figs.
about 10 A.M. the vapor pressure decreases as convectional currents reach higher and higher and mix the lower air with the drier air above until the principal minimum is reached at about 6 P.M. After this, evaporation, even though small is able to raise the vapor pressure in the absence of convection. In a moderately humid climate, such as that of Columbus, Ohio, the maximum in summer comes at about 10, as in the drier region, but the minimum is not reached until sunrise, when cooling has condensed a maximum of the water vapor. In a marine climate, using San Francisco as typical, the vapor pressure depends almost entirely on the temperature, and so the maximum comes at about 2 P.M. and the minimum around sunrise.
In the annual period the relative humidity is usually highest with the lowest temperature; but the vapor pressure varies directly with the annual temperature changes. The vapor pressure is 2 to 4 times as great in summer as in winter in most of the United States. The distribution of relative humidity depends, (1) on the temperature of the air, (2) on the proximity of the main source of moisture, (3) on the prevailing wind direction, and (4) on the topography to windward. East of the Rockies, April is generally the month of lowest relative humidity; while west, the mid-summer months are driest. In most of the United States, the highest relative humidity comes in the colder months, except in the southeast where it may occur in late summer or early fall. The lowest relative humidities occur in the far southwest, and in the lee of high mountains elsewhere, while the highest occur near the oceans, similarly, on the lee shores of the Great Lakes, and on the windward sides of mountains. On Pikes Peak and Mount Washington the humidities are generally high and show little variation. In the western half of the country the record minima range from 2 to 10 per cent., while in the eastern half, the lowest are 10 to 20 per cent. Since absolute humidity is controlled by temperature more than by any other factor for most of the country, the lowest vapor pressure comes in winter, and is experienced
in the coldest part of the United States. In summer, the lowest is in the lee of the Sierra Nevadas. It is rather surprising to learn that the July vapor pressures about YumaArizona, in almost the hottest and driest part of the Arizona desert are as high as those about the cool Great Lakes. Nothing could emphasize more strongly the fact that we feel in terms of relative humidity rather than in terms of absolute humidity.
In all the humidity tables and maps of Mr. Day's contribution we see a complex weather element which depends on the two variables, temperature and moisture. Humidity maps are in this respect on a par with snowfall maps; but they are less complex than those of evaporation, in which wind enters as another factor.
CHARLES F. BROOKS
LIMITS OF THE GENERA VANDELLIA AND URINOPHILUS
My monograph on the Pygidiidae was published September, 1918. I was not able to state the limits of the genus Vandellia nor to indicate the type of the genus Urinophilus. These minute fishes are found in the tropical lowlands of South America. They attach themselves to other animals and drink the blood. Some of them are said to enter the urethra of bathers, and being provided with erectile, retrorse spines on the opercles can not be withdrawn. If not excised they finally enter the bladder and cause death.
It was found during the preparation of the monograph that some of the species contain teeth on the mandibles, others not. It was not known whether the type specimen of the genus Vandellia contained mandibulary teeth or not. The specimens are in the Jardin des Plantes, Paris, and were not accessible during the war. Dr. J. Pellegrin has recently examined these specimens and reports that the types of Vandellia cirrhosa Cuv. & Val. and of V. Wieneri do not have mandibulary teeth and the name Vandellia may, therefore, be restricted to those species without mandibulary teeth, cirrhosa, plazai, wieneri and hasemani,
The name Urinophilus becomes, thereby, restricted to the only known species with teeth on the tips of the mandibular rami, Urin ophilus sanguineus (E.). The species Urinophilus sanguineus is known from one specimen, 62 mm. collected by Mr. Haseman at San Antonio de Rio Madeiro, Brazil. Its alimentary canal was gorged with blood.
The genera Vandellia and Urinophilus are members of the Pygidiida, a family of the Nematognathi, the cat-fish-like fishes. In most of these the maxillary is reduced to a rudiment forming the base of the chief barbel of the catfish. In Urinophilus and Vandellia the maxillary bone carries peculiar claw-like teeth. In the monograph mentioned above the tooth-bearing maxillary was labelled "premaxillary" in the explanation of Figs. 35 A and B, and in Fig. 37.
C. H. EIGENMANN
THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE SECTION H-ANTHROPOLOGY AND PSYCHOLOGY. II
Racial differences in mental fatigue: T. R. GARTH. An experiment was given to school children of three races-white, Indian and negro, involving a simple task which all could perform. The problem was to ascertain which race showed least falling away in a task of continuous performThe young group worked for twenty-eight minutes and the older group for forty-two minutes. The Indians, as a group, excel the whites in endurance but not in total performance.
Supernormal memory: P. F. SWINDLE. Ordinarily, the term hysteria is a name applied to certain spectacular forms of behavior which arise quite suddenly and which consist of strong and very permanently associated responses. form of behavior may be called a somnambulism, a fugue, a hysterical fit, or a special personality; and it is manifested only by those persons in whom associations are easily and at the same time quite permanently formed. If, in this sense, a person possesses an exceptionally good memory, a single unusual occurrence will probably suffice to establish in him a series of strong responses which will be manifested later as a somnambulism. It is profitable to speak of "big" somnambulisms and "little" somnambulisms, or spectacular somnambulisms and ordinary somnambulisms. Hysteria is
entirely a relative term. The terms amnesia and dissociation of the personality, which are so frequently used in speaking of hystericals, are misleading. Each of them should mean that if a person is occupied in one way, he is ordinarily not doing other things or thinking in other ways at that time. For example, only a few minutes ago I was occupied in thinking about a certain demonstration that a katydid can exert a force of at least thirty pounds with its ovipositor. While occupied in this way, I had complete amnesia for a dog I once owned; and at the time that I was thinking about my dog, I had complete amnesia for the experiment with the insect. My dog and the insect established in me two "little" somnambulisms; and I am never active in both ways at the same time. Likewise, a typical hysterical remembers his somnambulism only under the condition that he manifests it again; and when he the cases of typical hysteria which have come under my observation, many of the somnambulisms manifests it he has amnesia for other things. In or personalities were remarkably well associated. This circumstance makes it easy to produce artificially any of the existing states; and it is also responsible for the remarkable periodicity in the manifestations, by certain patients, of their established somnambulisms.
Definitions of mind offered by college students: C. R. GRIFFITH. The purpose of this investigation was (a) to obtain a definite expression of the nature of the beliefs and prejudices about "mind'' which are held by common-sense, and (b), to point out some of the antecedents of these notions. Definitions of "mind" obtained in a naïve manner from students at the University of Illinois are suggestive of the beliefs of popular opinion at large, and indicate, as well, the degree in which the laymen lags behind the trend of scientific thought. A tabulation of the definitions under appropriate categories discloses the fact that popular opinion engages in little or no critical reflection upon the matter. Conceptions of mind as a power, force, energy, guide or faculty are frequent, as are also conceptions confusing mind with the brain, the nervous system, or some internal organ. Less frequent notions make use of such terms as "soul," "spirit," "personality" or "storehouse."' Most of the definitions are, in fact, plainly reminiscent of the days of magic and of worn-out philosophies and discarded theories. Moreover, they represent in an undisguised way the wishes and desires of the men who value them. Over the whole is a thin sur
facing of modern science. The opinions, thus formed, are garbled in the telling, and betray, for the most part, a notable want in critical ability as well as a lack of substantial knowledge.
Organization of course of study in the elementary school: HELEN T. WOOLLEY.
Contributions of experimental psychology to the psychology of the elementary school branches: C. T. GRAY.
Safety-first education in school: M. J. MAYO. The loss of life and property in the United States through avoidable accident has become well nigh a national reproach. There is a growing public sentiment against the continuance of this evil. Largely through the influence of the National Safety Council, industrial accidents have been materially reduced. This has been effected through two means: (1) the appliance of safety devices to machinery wherever possible; and (2) a campaign of safety education among workmen. What are known as public accidents, however, show no decline. In the home and on the streets and highways an increasing number of serious and fatal accidents occur. The toll among the school population is large. The teaching of accident prevention is now admittedly a school problem. No other kind of education can more completely justify itself. Public safety can be promoted through two means: (1) the elimination of all avoidable sources of danger; and (2) adequate safety education. Safety education consists of (1) a thorough knowledge of all common danger situations, (2) correct habits of behavior in their presence, and (3) high ideals and right attitudes in regard to safety. We must teach definitely under what circumstances explosives and poisons are dangerous, just how it is that accidental burns and falls occur, just what our habits of behavior on the streets should be. We must act consistently and habitually in accord with this knowledge. This behavior can be secured only through high ideals of the value of human life and limb and a positive attitude towards safety. Our ideals must be dynamic in character. Only, for instance, when we have created an active ideal among the boys a sort of public sentiment-that condemns riding on the rear end of street cars as a piece of recklessness and stupidity, can this source of fatal accident be eliminated.
The distribution of grades in large lecture rooms: C. R. GRIFFITH. The distribution according to seating arrangement of the grades of students reg. istered in large lecture classes discloses a variation that can not be attributed to differences in