641 



SCIENTIFIC SIDE-LIGHTS 



Spectrui 

 Speed 



speak each in his native tongue, only 

 such words as belong to the inter jectional 

 and imitative classes will be naturally in- 

 telligible, and, as it were, instinctive to 

 both. Thus the savage, uttering the sound 

 " waow ! " as an explanation of surprise and 

 warning, might be answered by the white 

 man with the not less evidently significant 

 " sh !" of silence, and the two speakers 

 would be on common ground when the native 

 indicated by the name " bioirri," his cudgel, 

 flung " whirring " through the air at a flock 

 of birds, or when the native described as a 

 " jakkal-yakkal " the bird called by the for- 

 eigner a " cockatoo." With these and other 

 very limited classes of natural words, how- 

 ever, resemblance in vocabulary practically 

 ceases. The Australian and English lan- 

 guages each consist mainly of a series of 

 words having no apparent connection with 

 the ideas they signify, and differing utter- 

 ly. DANIEL WILSON Anthropology, ch. 6, p. 

 23. (Hum., 1885.) 



3176. SPEECH, PURPOSE UNDER- 

 LYING Man Demands a Word for Each 

 Thing. When a dog yelps in front of a door, 

 and his master, understanding his desire, 

 opens it, the dog may, after a certain num- 

 ber of repetitions, get to repeat in cold 

 blood a yelp which was at first the involun- 

 tary inter jectional expression of strong emo- 

 tion. The same dog may be taught to " beg " 

 for food, and afterwards come to do so de- 

 liberately when hungry. ... In each of 

 these separate cases the particular sign may 

 be consciously noticed by the animal, as 

 distinct from the particular thing signified, 

 and will thus, so far as it goes, be a true 

 manifestation of language. But when we 

 come to man we find a great difference. He 

 has a deliberate intention to apply a sign to 

 everything. The linguistic impulse is with 

 him generalized and systematic. For things 

 hitherto unnoticed or unfelt he desires a 

 sign before he has one. Even tho the dog 

 should possess his "yelp" for this thing, 

 his " beg " for that, and his auditory image 

 " rat " for a third thing, the matter with 

 him rests there. If a fourth thing interests 

 him for which no sign happens already to 

 have been learned, he remains tranquilly 

 without it, and goes no further. But the 

 man postulates it, its absence irritates him, 

 and he ends by inventing it. This general 

 purpose constitutes, I take it, the peculiarity 

 of human speech, and explains its prodigious 

 development. JAMES Psychology, vol. ii, ch. 

 22, p. 356. (H. H. & Co., 1899.) 



3177. SPEED A SAFEGUARD The 



Humming-Mrd Secure with Brilliant Colors 

 Birds of Prey Pursue in Vain. In their 

 [the humming-birds'] plumage, . . . Na- 

 ture has strained at every variety of effect, 

 and reveled in an infinitude of modifica- 

 tions. How wonderful their garb is, with 

 colors so varied, so intense, yet seemingly so 

 evanescent! the glittering mantle of pow- 



dered gold; the emerald green that changes 

 to velvet black; ruby reds and luminous scar- 

 lets; dull bronze that brightens and burns 

 like polished brass, and pale, neutral tints 

 that kindle to rose and lilac-colored flame. . . . 

 Excessive variation in this direction is 

 checked in nearly all other birds by the need 

 of a protective coloring, few kinds so greatly 

 excelling in strength and_ activity as to be 

 able to maintain their existence without it. 

 Bright feathers constitute a double danger, 

 for not only do they render their possessor 

 conspicuous, but, just as the butterfly chooses 

 the gayest flower, so do hawks deliberately 

 single out from many obscure birds the one 

 with brilliant plumage; but the rapacious 

 kinds do not waste their energies in the vain 

 pursuit of humming-birds. These are in the 

 position of neutrals, free to range at will 

 amidst the combatants, insulting all alike, 

 and flaunting their splendid colors with 

 impunity. They are Nature's favorites, en- 

 dowed with faculties bordering on the mi- 

 raculous, and all other kinds, gentle or fierce, 

 ask only to be left alone by them. HUDSON 

 Naturalist in La Plata, ch. 16, p. 219. (C. 

 & H., 1895.) 



3178. SPEED, MEASURABLE, OF 

 NERVE ACTION Volition Takes Time. 

 By a series of very ingenious and conclu- 

 sive experiments, the rate of passage of the 

 nerve-force has been shown to be about 

 ninety feet per second. This measure is 

 made upon the course of the nerve-threads, 

 and does not include the passage through 

 the gray matter of the centers, with their 

 mass of corpuscles. Now, the time of a com- 

 plete circuit of action, beginning at a stimu- 

 lation of the senses, and ending in certain 

 movements, depends partly on the time of 

 moving along the nerves, and partly on the 

 time of passing through the centers, where 

 a number of corpuscles must be traversed. 

 Estimates have been made as to this last 

 operation, which, from the nature of the 

 case, is likely to be somewhat various; for 

 not only may the central mass to be pene- 

 trated be of various extent, but also there 

 is a liability to conflicting currents. The 

 case of least internal delay is what is termed 

 reflex action, where a motion answers to 

 a stimulus without the intervention of the 

 will, as in the involuntary start from a 

 pinch in the hand. By experiments on frogs 

 Helmholtz found that a period of from & 

 to A of a second was occupied by the re- 

 flex act; now the length of the entire nerve- 

 tract could only be a few inches, which 

 would hardly occupy the two-hundredth of a 

 second, if that tract were an uninterrupted 

 nerve thread. BAIN Mind and Body, ch. 3, 

 p. 10. (Hum., 1880.) 



3179. SPEED OF MENTAL ACTION 



Association Intensely Rapid Naming of 

 Separate Letters Proof - reading. Heading 

 exemplifies this kind of cohesion [by mental 

 association]. It is an uninterrupted and pro- 



