Obliteration 

 Ocean 



SCIENTIFIC SIDE-LIGHTS 



496 



stone. . . . The hemisphereless pigeon 

 is in the highest degree tame, and fears 

 man as little as cat or bird of prey." 

 JAMES Psychology, vol. i, ch. 2, p. 77. (H. 

 H. & Co., 1899.) 



2438. OBSERVATION MISINTER- 

 PRETED Ant Recognized by Mates after Ab- 

 sence Recognition Specific, Not Individual. 

 How easy it is to misinterpret an ob- 

 servation if the very greatest care is not 

 taken in recording it, and if it is impossible 

 to vary the circumstances by experiment, 

 and so obtain accurate knowledge of its 

 conditions, is well shown by the following 

 facts : Pierre Huber, one of the most reliable 

 students of the habits of ants, stated that 

 he had assured himself that an ant, if taken 

 from the nest and returned after an interval 

 of four months, was recognized by its former 

 companions; for they received it friendlily, 

 while members of a different nest, even tho 

 they belonged to the same species, were 

 driven away. Huber regards this as evi- 

 dence of the extraordinary accuracy of mem- 

 ory in these insects. Now the correctness 

 of his observation cannot be doubted; and, 

 besides, it has been confirmed by another 

 experienced investigator Sir John Lubbock 

 [Lord Avebury]. At first sight, therefore, 

 the conclusion seems perfectly justifiable. 

 But if a single individual were really rec- 

 ognized after so long an interval, think 

 what the general mental capacity of the 

 ants must be! Fortunately, Lubbock made 

 the matter a subject of experiment. He 

 took ant larvae from the nest and did 'not 

 put them back again till they were fully de- 

 veloped. The result was that they too were 

 quite friendlily received. Plainly, then, there 

 can be no question of an act of individual 

 recognition. There must be some character- 

 istic peculiar to all the members of a par- 

 ticular nest, possibly a specific odor, which 

 determines the instinctive expression of 

 " friendship." WUNDT Psychology, lect. 23, 

 1, p. 344. (M., 1898.) 



2439. OBSERVATION, SCIENCE 

 TEACHES CORRECT HABITS OF Mind 

 as an Orderly Storehouse. To observe right- 

 ly and truly, and as science teaches us to 

 observe, is a habit which lies at the foun- 

 dation of all order in mental things; and 

 without this habit of looking at things in 

 their due sequence, thoughts and thinking 

 can only appear as acts and processes which 

 exist but to confuse and bewilder the think- 

 er. And to the young, in their responsible 

 duty too little thought of in its serious 

 nature both by pupil and teachers of lay- 

 ing up stores of mental wealth for future 

 use, how great a boon must be the acquire- 

 ment of these orderly habits in the work 

 of the mind! The great difficulty, I pre- 

 sume, of every educator of youth is not to 

 arouse his pupils' thoughts, not to incite 

 them to think, but to train them so to think 

 that they shall understand, appreciate for 

 themselves, and in due order arrange, for 



future use, the material which their edu- 

 cation furnishes. For the well-balanced 

 mind is like a duly arranged storehouse, 

 where the fruits of each year's industry are 

 not only duly arranged within, but are capa- 

 ble of being brought forth for use in good 

 order and at the proper season and time. 

 ANDREW WILSON Science-Culture for the 

 Masses, p. 28. (Hum., 1888.) 



2440. OBSTACLES UNIMAGINED 



Boats Checked by Floating Rock Drifting 

 Pumice Covering the Sea. Every one is fa- 

 miliar with the fact that pumice floats upon 

 water; this it does, not because it is a ma- 

 terial specifically lighter than water, but 

 because cavities filled with air make up a 

 great part of its bulk. If we pulverize pum- 

 ice we find the powder sinks readily in wa- 

 ter, but the rock in its natural condition 

 floats for the same reason that an iron ship 

 does because of the air-chambers which it 

 encloses. When this pumice is ejected from 

 a volcano and falls into a river or the 

 ocean, it floats for a long time, till decom- 

 position causes the breaking-down of the 

 thin glassy partitions between the air-cham- 

 bers, and causes the admission of water into 

 the latter, by which means the whole mass 

 gets water-logged. Near the Liparis and 

 other volcanic islands the sea is sometimes 

 covered with fragments of pumice to such 

 an extent that it is difficult for a boat to 

 make progress through it, and the same 

 substance is frequently found floating in the 

 open ocean and is cast up on every shore. 

 JUDD Volcanoes, ch. 4, p. 73. (A., 1899.) 



2441. OBSTACLES, WAVES OF 

 LIGHT FLOW AROUND Newton's Objec- 

 tion Answered Diffraction. Newton, who 

 was familiar with the idea of an ether, 

 and who introduced it in some of his specu- 

 lations, objected [nevertheless] that if light 

 consisted of waves, shadows could not ex- 

 ist, for that the waves would bend round 

 the edges of opaque bodies and agitate the 

 ether behind them. He was right in affirm- 

 ing that this bending ought to occur, but 

 wrong in supposing that it does not occur. 

 The bending is real, tho in all ordinary 

 cases it is masked by the action of inter- 

 ference. This inflection of the light receives 

 the name of diffraction. TYNDALL Light, 

 lect. 2, p. 80. (A., 1898.) 



2442. OCCIDENT AND ORIENT 

 UNITED BY MEDITERRANEAN The 



Sea a Bond of Union. That which has ren- 

 dered the geographical position of the Medi- 

 terranean most beneficial in its influence on 

 the intercourse of nations is the proximity 

 of the eastern continent, where it projects 

 into the peninsula of Asia Minor; the num- 

 ber of islands in the JSgean Sea, which 

 have served as a means for facilitating 

 the spread of civilization, and the fissure be- 

 tween Arabia, Egypt, and Abyssinia, through 

 which the great Indian Ocean penetrates 

 under the name of the Arabian Gulf or the 



