Necessity 

 jferves 



SCIENTIFIC SIDE-LIGHTS 



tribe shall consist. Killing off a few ob- 

 noxious ones may often better the chances of 

 those that remain. And killing off a neigh- 

 boring tribe from whom no good thing 

 comes, but only competition, may materially 

 better the lot of the whole tribe. Hence the 

 gory cradle, the bellum omnium contra 

 omnes, in which our race was reared; hence 

 the fickleness of human ties, the ease with 

 which the foe of yesterday becomes the ally 

 of to-day, the friend of to-day the enemy of 

 to-morrow; hence the fact that we, the 

 lineal representatives of the successful en- 

 actors of one scene of slaughter after an- 

 other, must, whatever more pacific virtues 

 we may also possess, still carry about with 

 us, ready at any moment to burst into flame, 

 the smoldering and sinister traits of char- 

 acter by means of which they lived through 

 so many massacres, harming others, but 

 themselves unharmed. JAMES Psychology, 

 vol. ii, ch. 24, p. 409. (H. H. & Co., 1899.) 



2399. NECESSITY OF PAIN Its Chief 

 Use Not for the Individual, but for the 

 Race. We must, therefore, accept pain as a 

 fact existing by a deep necessity, having its 

 root in the essential order of the world. If 

 we are to understand it, we must learn to 

 look on it with different eyes. And does not 

 a different thought suggest itself even while 

 we recognize that the others fail? For if 

 the reason and the end of pain lie beyond 

 the results that have been mentioned, then 

 they lie beyond the individual. Pain, if it 

 exist for any purpose, and have any end or 

 use and of this what sufferer can endure to 

 doubt? must have some purpose which ex- 

 tends beyond the interest of the person who 

 is called upon to bear it. ... 



These uses of pain, which concern the one 

 who suffers only [as leading to avoidance of 

 danger, etc.], must fail and be found insuffi- 

 cient. . . . But when we extend our 

 thought, and recognise not only that there 

 are, in pain, ends unseen by us, but that 

 these ends may not be confined within the 

 circle of our own interests, surely a light 

 begins to glimmer through the darkness. 

 While we look only at that which directly 

 concerns the individual who suffers, no real 

 explanation of suffering, no satisfaction 

 that truly satisfies, can be found. But if we 

 may look beyond and see in our own suffer- 

 ings, and in the sufferings of all, something 

 in which mankind also has a stake, then 

 they are brought into a region in which the 

 heart can deal with them and find them 

 good. And if the heart, the reason also. 

 For here it is the soul that is the judge ; 

 and if the heart is satisfied, the reason also 

 is content. HINTON The Mystery of Pain, 

 p. 19. (Hum., 1893.) 



2400. NEEDLE, MAGNETIC, AN- 

 CIENT KNOWLEDGE OF Early Chinese 

 Record of " Needle Pointing South " 

 Polarity a Puzzle. No definite statement, 

 however, is found until the end of the elev- 

 enth century is reached, and then in a work 



entitled " Mung-Khi-pithan " we meet the 

 following extraordinary passage : 



" The soothsayers rub a needle with the 

 magnet stone so that it may mark the 

 south; however, it declines constantly a lit- 

 tle to the east. It does not indicate the 

 south exactly. When this needle floats on 

 the water it is much agitated. If the finger- 

 nails touch the upper edge of the basin in 

 which it floats they agitate it strongly, only 

 it continues to slide and falls easily. It is 

 better, in order to show its virtues in the 

 best way, to suspend it as follows: Take a 

 single filament from a piece of new cotton 

 and attach it exactly to the middle of the 

 needle by a bit of wax as large as a mustard- 

 seed. Hang it up in a place where there is 

 no wind. Then the needle constantly shows 

 the south; but among such needles there 

 are some which, being rubbed, indicate the 

 north. Our soothsayers have some which 

 show south and some which show north. Of 

 this property of the magnet to indicate the 

 south, like that of the cypress to show the 

 west, no one can tell the origin." BENJA- 

 MIN Intellectual Rise in Electricity, ch. 3, p. 

 75. (J. W., 1898.) 



24O1. 



Occident Indebted 



to Orient. While the gradually developed 

 knowledge of relations in space incited men 

 to think of shorter sea routes, the means for 

 perfecting practical navigation were like- 

 wise gradually increased by the application 

 of mathematics and astronomy, the inven- 

 tion of new instruments of measurement, 

 and by a more skilful employment of mag- 

 netic forces. It is extremely probable that 

 Europe owes the knowledge of the northern 

 and southern directing powers of the mag- 

 netic needle the use of the mariner's com- 

 pass to the Arabs, and that these people 

 were in turn indebted for it to the Chinese. 

 . . . In the third century of our era, un- 

 der the dynasty of Han, there is a descrip- 

 tion given in Hiutschin's dictionary Schue- 

 \ven of the manner in which the property of 

 pointing with one end toward the south may 

 be imparted to an iron rod by a series of 

 methodical blows. Owing to the ordinary 

 southern direction of navigation at that 

 period, the south pointing of the magnet is 

 always the one especially mentioned. A cen- 

 tury later, under the dynasty of Tsin, 

 Chinese ships employed the magnet to guide 

 their course safely across the open sea, and 

 it was by means of these vessels that the 

 knowledge of the compass was carried to 

 India, and from thence to the eastern coasts 

 of Africa. HUMBOLDT Cosmos, vol. ii, pt. ii, 

 p. 253. (H., 1897.) 



24O2. NEGATION OF FIXED MODES 

 GIVES MAN PREEMINENCE New Prin- 

 ciples for New Cases. In them [the lower 

 animals] fixed habit is the essential and 

 characteristic law of nervous action. The 

 brain grows to the exact modes in which it 

 has been exercised, and the inheritance of 

 these modes then called instincts would 



