Popular Science Monthly/Volume 58/March 1901/Scientific Literature

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Scientific Literature.

THE FOUNDATIONS OF KNOWLEDGE.

Little doubt can exist longer that the coolness which marked the relationship between Science and Philosophy from about 1840 until within the last decade is passing away rapidly. Thanks partly to the development of experimental psychology, partly to the broader training given at our colleges, where science has won a recognized place in the undergraduate course, the younger men who specialize in philosophy possess some acquaintance with the scientific attitude and temper. To them, and to the professed votary of science, the new work, entitled 'Foundations of Knowledge,' by Professor Ormond, of Princeton (Macmillan), can not fail to present some attractive and some curious considerations. In witness of his sympathy with the modern outlook, and to a certain extent under pressure of its demands, the 'McCosh Professor,' of all people, has striven hard to adopt an experiential basis. He sees quite clearly that neither the hide-bound empiricism of the traditional English school, nor the vaulting a priori dialectic of Hegel and his English-speaking derivants, suffice to philosophical salvation at present. Accordingly, he has provided a sober, straightforward analysis of the implications hidden under such terms as Experience, Knowledge, Reality. This forms the First Part of his essay. Having thus expelled traditional subjects of contention, he proceeds to consider the various characteristic ways in which knowledge grows from a less to a more complex synthesis of things. In this connection, he deals with the same material upon which metaphysicians have racked their brains time out of mind—Space, Time, Quantity, Quality, Cause, Substance, taking the stage successively. And it must be said that, although Professor Ormond's style is a trifle heavy, he contrives to set forth some sensible, fresh and, moreover, plain conclusions. But, as has been hinted, these matters are ancient history with all philosophers, as with some scientific workers. And so, this Second Part of the work does not stop here. As many are aware, the ideas just mentioned may be called static; and the modern tendency—very strong in science, equally strong with the younger philosophical men—makes its presence felt in Professor Ormond's discussion of dynamic aspects of experience. The conception of a social mind, leading to the ideas of relationship, interdependence and unitary mental life expressing itself in individuals, has attracted his close attention. It can hardly be said that he has embraced all the conclusions to which such conceptions lead necessarily. He makes reservations, or rather, the habit of his mind and the influences of his education induce him to stop short midway in his progress. Consequently, it turns out, in the Third Part of the book, that human experience possesses a 'transcendent or superordinary element.' Here, it seems, philosophy finds its peculiar work, while science deals with the ordinary or relative. Even a superficial acquaintance with the history of thought reminds us that this is a very old idea; one, too, which, like other old ideas, has been petarded often. But Professor Ormond presents it in a fresh way, and in as reasonable fashion as it is capable of assuming. Not that he justifies it, for it cannot be justified, except by Deity. At the same time, through its instrumentality he calls attention to one aspect of knowledge that has been subject to neglect of late. From this brief outline, the reader will gather, first, that the book possesses a certain originality of its own, it stands for solid work by its author and affords one the pleasure that such work gives. Second, it is attractive, because it marks a stage of transition. Ten years hence, these clean-cut distinctions within experience will have become impossible. The work is, therefore, to be commended as a faithful and forthright representation of that type of thinking which, though well aware of the futilities of eighteenth century dualism, has not yet awakened to the demands of twentieth century system. Being thus a type, it is well worth taking into consideration.

 

STATIONARY RADIANTS TO SHOWERS OF SHOOTING STARS.

The radiant of a shower of shooting stars is the point or area from which all the stars appear to move when perspectively projected on the celestial vault. If the tracks of a shower of meteors are laid down on a star map, and if these tracks are prolonged, all of them will intersect in a point, or, at least, within a small area—the radiant. The meteors are really moving in parallel straight lines in space. Their paths are perspectively projected into great circles of the celestial sphere, and have a common vanishing point. The case is easily understood by that of the 'sun drawing water,' which is often seen about sunset. The rays of the sun are really parallel, but they seem to radiate in all directions from the sun's disc in great circles that have a common vanishing point.

This perspective theory demands that the radiant point of a shower of meteors should rise, culminate and set by the earth's diurnal motion, precisely as the sun, or a star, rises, culminates and sets. The meteors on any night do, in fact, radiate from spots which remain fixed among the stars, and which rise, culminate and set as do the stars themselves. If the shower continues for many nights (like the Perseid shower, for instance) the place of the radiant usually shifts among the stars, as it ought to do, since its position is due to a geometric configuration which changes as the earth moves. The perspective appearances change as the place of the spectator is altered by the earth's motion in its orbit. Mr. W. F. Denning, of Bristol, England, an experienced and assiduous observer of meteors, reports that he has found cases where the appearances differ from these normal conditions. For certain showers of meteors, the radiant does not change its place among the stars as the earth moves in its orbit, but, on the contrary, the radiant remains stationary for weeks. A typical case of the sort is the shower of the Orionids. This shower persists for about two weeks (October 10-24), and the radiant remains stationary near the star ν Orionis, instead of shifting with the earth's motion as the laws of celestial perspective demand.

No satisfactory explanation of such stationary radiants has been forthcoming; and many astronomers have doubted the correctness of Mr. Denning's observations on that account. Granting that the observations are correct, an explanation of the phenomenon has been given by Professor von Niessl, of Brünn, and this explanation was briefly reported by Prof. Alexander Herschel at a recent meeting of the Astronomical Society of France. From a rather meager account of the report it appears that M. von Niessl has sought for a path of a meteor stream so situated in space and so curved that the observed phenomena would necessarily follow. Given the phenomena and the fact that they are produced by the perspective projection of the actual paths of meteors in space, he has inquired what the paths must be to satisfy all the conditions. If we assume swarms of meteors, moving with small velocities in space, in hyperbolic orbits nearly parallel, the orbits being asymptotic to the sun, meteors proceeding from such swarms would seem to have a stationary radiant. Moreover, such meteors must originate in certain fixed emissive centers in the stellar regions (beyond the solar system). The phenomena for certain aerolites whose fall has been observed are accounted for by reasonable assumptions as to the existence of the cosmical centers of emission, primitive velocity and direction.

Without seeing M. von Niessl's original paper it is impossible to give more than the foregoing brief report. It is obvious that if we assume a set of centers of emission exterior to the solar system, and suppose that they send out swarms of meteors which, in time, reach the solar system, it is possible to make reasonable assumptions as to velocity, etc., that will account for all the observed phenomena. A geometrical explanation of stationary radiants can be had in this way. It is not yet possible to say whether there is sufficient physical evidence to make the existence of such extra-solar emissive centers probable. All that can now be done is to report this essay towards a physical explanation of a very puzzling phenomenon.

 

THE UTILIZATION OF FOOD AND ALCOHOL IN THE HUMAN BODY.

Widespread interest has been taken in the results reported by Prof. W. O. Atwater on the food value of alcohol. These alcohol experiments constitute a part of a series of experiments on the utilization of food in the human body which have been in progress for a number of years. A technical description of a number of them forms a part of a bulletin by Professor Atwater et al. on 'The Metabolism of Matter and Energy in the Human Body,' just issued by the United States Department of Agriculture. The bulletin describes in detail fourteen experiments carried on with human subjects in the Atwater-Rosa respiration calorimeter. It presents additional data bearing upon the metabolism of matter and energy in the human body under conditions of rest and work, the conservation of energy under these conditions, the action of the ordinary food nutrients in the body, and the effect of muscular work upon nitrogen metabolism.

The aim in these experiments was to furnish the subject with approximately the quantity of nitrogen, carbon and energy in the basal ration that would be required to keep him in nitrogen and carbon equilibrium. This was practically attained. Upon the addition to the basal ration of an amount of alcohol or sugar furnishing approximately 500 calories of energy per day, it was found that the body appeared to store an. amount of fat having practically an isodynamic value with the alcohol or sugar eaten. It is doubtful whether all the energy in the sugar was actually available to the body, some loss being sustained in transferring the sugar from the alimentary canal into the circulation. Assuming 98 per cent, of the energy of the sugar to be actually available to the body, it is calculated that this would give 505 calories of available energy furnished by the sugar, and 477 calories of extra fat stored by the body, as compared with the preceding experiments upon the basal ration.

The close agreement between the quantities of heat actually determined and the theoretical amounts furnished by the materials actually oxidized in the body is one of the interesting features of the experiments, and indicates the degree of accuracy which has been attained with the apparatus and the methods employed.

An important scientific result of these investigations thus far has been to demonstrate, in a manner which has never been done before, the application of the law of the conservation of matter and of energy in the human body.

The report is largely one of progress. The authors propose in future experiments to study further the metabolism of different classes of nutrients and the relative replacing power of the energy as furnished by different materials.