IN a previous chapter we have studied the changes which colored surfaces experience when viewed under various kinds of illumination, or when modified in appearance by the admixture of more or less white or colored light. The appearance which a colored surface presents to us can, however, be altered very materially, by a method which is quite different from any of those that have thus far been mentioned: we can actually change color to a considerable extent without at all meddling with it directly, it being for this purpose only necessary to alter the color which lies adjacent to it.
THE undeveloped human intelligence does not initiate. Adhering tenaciously to whatever his fathers taught him, the primitive man deviates into novelty only through unintended modifications. That which every one now knows holds of languages, that they are not devised but evolve, equally holds of usages.
THE original investigator of Nature soon learns by constant experience that descriptions or even drawings, however correct, do not exactly represent the objects themselves, but are imperfect and ideal abstractions. This is true, to a greater or less extent, of every drawing of the simplest organ or tissue, and of every description of a species or genus of animals or plants; but it is especially and most emphatically true of all attempts at definitions of the larger and more comprehensive groups of organisms.
PROFESSOR TYNDALL BEFORE THE ENGLISH COPYRIGHT COMMISSION.1
QUESTION (Chairman). I believe you have published not only in England, but in the United States? Answer. I have published about a dozen volumes in England, and most, if not the whole of them, have been reproduced in the United States. Q. With your sanction?
LITTLE as it appears to be appreciated, there is to-day no question of sanitary science of greater vital importance than that of the quality of the water-supply entering into the daily domestic economy. The requirements and refinements of modern civilization demand not only a plentiful but a profuse supply of water, and at a moderate cost— facts long ago recognized and acted upon.
I NOW proceed with the review of the Emotions as motives in education. PLAY OF THE EMOTIONS OF ACTICVITY.—Nothing is more frequently prescribed in education than to foster the pupils’ own activity, to put them in the way of discovering facts and principles for themselves.
SOUND is the sensation peculiar to the ear. This sensation is caused by rapidly-succeeding to-and-fro motions of the air which touches the outside surface of the drum-skin of the ear. These to-and-fro motions may be given to the air by a distant body, like a string of a violin.
SOME twenty-five years ago, when Foucault’s ingenious experiment for proving the earth’s motion on its axis was in vogue, the idea occurred to us that that fact might be proved in another way. Foucault’s method, it will be remembered, consisted in the vibration of the pendulum in a fixed direction, the earth’s motion being disclosed by the angular deviation of a given chalked line from that direction.
I HAVE spent some years as a botanist in the tropics of both hemispheres, and in the mean time have studied pretty thoroughly the tropical domesticated plants. In America and in Asia the principal domesticated tropical plants are represented by the same species; for instance, Manihot utilissima, whose roots yield a fine flour, the tarro (Colocasia esculenta), the Spanish or red pepper (Capsicum annuum), which is in far more general use than the black pepper, and whose numerous domestic varieties justify the inference that it has been cultivated from a very early period.
I SHALL begin with an unequivocal statement of my position: the study of the English language and literature should occupy the central place—the place of honor—in every scheme of higher education for English-speaking men and women. This primacy I claim for two principal reasons: first, the knowledge obtained from this study is of most worth in the practical affairs of real life; second, the right study of English may be made the instrument of the highest culture of the mind.
SOME months ago we described very rapidly the principal features of that widely-extended and enigmatical formation known as the Drift, and in conclusion indicated an intention to consider the views of geologists as to its cause, and in particular illustrate the paramount claims to our acceptance of the so-called Glacial Theory.
A FEW days ago I was invited by a medical friend to visit him at his house, and hear two musical mice sing a duet, the performance to begin punctually at 8 P. M. I had never heard a singing mouse, though I had read and been told a good deal of the vocal accomplishments the little animal occasionally displays; so I gladly availed myself of the opportunity, and duly arrived half an hour before the commencement of the concert.
WE in the present number of the MONTHLY offer to our readers a portrait of Mr. William Spottiswoode, F. R. S., D. C. L., LL.D., President of the British Association for the Advancement of Science, at its late session in Dublin. WILLIAM SPOTTISWOODE is the son of Andrew Spottiswoode, M. P., printer to the Crown and the House of Lords, and prominent in the history of printing for his earnest encouragement of every invention tending to perfect that important art. The son was born in London, January 11, 1825.
THE following communication, signed Charles A. Duvoisin, and published in a French journal, will no doubt be welcome to your readers, especially such of them as take an interest in the scientific education of the young. B. Is it not strange that teachers of natural history, in most countries, have utterly overlooked the very effective practical scientific instruction which the pupils of Latin and commercial schools receive already at a very early age?
THE contrasts of the deductive and inductive habits of mind are seen in philanthropy as well as philosophy, and give rise to two schools of reformers. What we may call deductive reformers start from general principles, and many of them never get much further.
SCIENTIFIC MEMOIRS. Being Experimental Contributions to a Knowledge of Radiant Energy. By JOHN WILLIAM DRAPER, M. D. Harper & Bros., 1878. Pp. 473. Price $3. THOSE who read the concluding paper of Dr. Montgomery in the October POPULAR SCIENCE MONTHLY, on the present aspects of the “Problem of Life,” will remember the admirable terms in which he refers to a discovery of Dr. J. W. Draper, which seems to have a most important bearing on this subject.
Parks and Gardens of Paris considered in Relation to the Wants of other Cities and of Public and Private Gardens. By W. Robinson, F. L. S. With numerous Illustrations. New York: Macmillan. Pp. 572. $7.50. American Ornithology; or, The Natural History of the Birds of the United States.
Effects of Oxygen inhaled at Different Temperatures.—Dr. B. W. Richardson finds great diversity in the action of oxygen on the animal economy according to the temperature of the gas when inhaled. Carefully-purified oxygen may be inhaled at 55° Fah. without a consciousness of the difference between it and common air.
THE American Association will next year hold its meetings at Saratoga, beginning on the last Wednesday of August. Prof. G. F. Barker, of Philadelphia, is the president. DIED, September 6th, at Brussels, Ernest Quetelet, of the Brussels Royal Observatory, aged about fifty-three years.