145 



SCIENTIFIC SIDE-LIGHTS 



Crystals 

 Cycle 



the other necessary conditions for the ex- 

 istence of the individual forms exist. 

 SEMPER Animal Life, ch. 9, p. 279. (A., 

 1881.) 



713. CURRENTS, ELECTRIC, TRAV- 

 ERSING THE OCEAN FLOOR The Sub- 

 marine Telegraph. And now we come to the 

 most wonderful of all telegraphs that 

 which transmits messages from continent to 

 continent, for thousands of miles, under the 

 depths of the sea. " Does it not seem all but 

 incredible to you," said Edward Everett in 

 his oration at the opening of Dudley Obser- 

 vatory, " that intelligence should travel for 

 two thousand miles along those slender cop- 

 per wires far down in the all but fathomless 

 Atlantic, never before penetrated by aught 

 pertaining to humanity, save when some 

 foundering vessel has plunged with her hap- 

 less company to the eternal silence and dark- 

 ness of the abyss? Does it not seem, I say, 

 all but a miracle of art, that the thoughts 

 of living men the thoughts that we think 

 up here on the earth's surface, in the cheer- 

 ful light of day about the markets and the 

 exchanges, and the seasons, and the elec- 

 tions, and the treaties, and the wars, and all 

 the fond nothings of daily life, should clothe 

 themselves with elemental sparks, and shoot 

 with fiery speed in a moment, in the twin- 

 kling of an eye, from hemisphere to hemi- 

 sphere, far down among the uncouth mon- 

 sters that wallow in the nether seas, along 

 the wreck-paved floor, through the oozy dun- 

 geons of the rayless deep; that the last in- 

 telligence of the crops, whose dancing tas- 

 sels will in a few months be coquetting with 

 the west wind on these boundless prairies, 

 should go flashing along the slimy decks of 

 old sunken galleons which have been rotting 

 for ages; that messages of friendship and 

 love, from warm living bosoms, should burn 

 over the cold green bones of men and women 

 whose hearts, once as warm as ours, burst 

 as the eternal gulfs closed and roared over 

 them, centuries ago! " PARK BENJAMIN 

 Age of Electricity, ch. 11, p. 247. (S., 1897.) 



714. CURSE OF SLAVERY Even An- 

 imals Degraded ~by Becoming Oppressors. 

 Here, then [among the slave-making ants], 

 as in the case of nestlings, the food-seeking 

 instinct and the power of distinguishing 

 food by sight have degenerated, and clearly 

 in consequence of disuse. Inasmuch as a 

 colony of red ants always owns plenty of 

 slaves, the food-seeking instinct has become 

 unnecessary, natural selection has ceased to 

 affect it, and it has gradually died out. 

 Other instincts, too, have been lost by these 

 red ants in consequence of their habit of 

 keeping slaves; they have quite forgotten 

 the art of nest-building and in part that of 

 tending their young. Other species of ants 

 devote much attention to their pupae, mov- 

 ing them about the nest from time to time, 

 and often carrying them out into the air and 

 sun, and they feed their larvae with the 

 greatest assiduity. But the red slave-ma- 



king ants have no such instincts; they care 

 nothing for their own young, and the species 

 would become extinct if they were suddenly 

 deprived of their slaves. So it is not only 

 among men that there is a curse upon 

 slavery; even animals become degraded by 

 it. WEISMANN Heredity, vol. ii, ch. 9, p. 

 26. (Cl. P., 1897.) 



715. CUTTING BY GLACIER RE- 

 SISTLESS Gigantic Rasp of Ice Record 

 " Graven with Iron Pen in Rock Forever " 

 (Job xix, 2Jf). On any surfaee over which 

 water flows we shall find that the softer 

 materials have yielded first and most com- 

 pletely. Hard dikes will be left standing 

 out, while softer rocks around them are 

 worn away furrows will be eaten into more 

 deeply fissures will be widened clay- 

 slates will be wasted while hard sandstone 

 or limestone and granite will show greater 

 resistance. Not so with surfaces over which 

 the leveling plow of the glacier has passed. 

 Wherever softer and harder rocks alternate, 

 they are brought to one outline; where 

 dikes intersect softer rock, they are cut to 

 one level with it; where rents or fissures 

 traverse the rock, they do not seem to have 

 been widened or scooped out more deeply, 

 but their edges are simply abraded on one 

 line with the adjoining surfaces. Whatever 

 be the inequality in the hardness of the 

 materials of which the rock consists, even 

 in the case of pudding-stone, the surface is 

 abraded so evenly as to leave the impression 

 that a rigid rasp has moved over all the un- 

 dulations of the land, advancing in one and 

 the same direction and leveling all before 

 it. AGASSIZ Geological Sketches, ser. ii, p. 

 40. (H. M. &Co., 1896.) 



716. CYCLE OF CHANGE Life the 

 Builder, Oxygen the Destroyer Science Has 

 A 7 o Explanation of Life. While the plant 

 is in great measure made up of non-nitro- 

 genized substances, the animal, on the other 

 hand, consists almost entirely of albuminous 

 compounds. The flesh, the nerves, and the 

 bones of our bodies all contain nitrogen, 

 and, like the vegetable albumen, are prone 

 to decay; and this change is constantly go- 

 ing on in our living members. In a most 

 profound sense, " in the midst of life we are 

 in death." The materials of our bodies are 

 being constantly renewed, and the great 

 mass of their structure changes in less than 

 a year. At every motion of your arm, and 

 at every breath you draw, a portion of the 

 muscles concerned is actually burned up in 

 the effort. During life, in some utterly 

 mysterious manner, beyond the range of all 

 human science, the various gases and vapors 

 of the atmosphere, together with a small 

 amount of a few earthy salts, are elaborated 

 into various organized structures. They 

 first pass into the organism of the plant, 

 and thence are transferred to the body of 

 the animal; but no sooner are they firmly 

 built into the animal tissues than a de- 

 structive change begins, by which before 



