633 



SCIENTIFIC SIDE-LIGHTS 



SRt! 



in diameter. You may look at the bubble 

 itself, or you may look at its projection 

 upon the screen; rich colors arranged in 

 zones are, in both cases, exhibited. Render- 

 ing the beam parallel, and permitting it to 

 impinge upon the sides, bottom, and top of 

 the bubble, gorgeous fans of color over- 

 spread the screen, rotating as the beam 

 is carried round the circumference of the 

 bubble. By this experiment the internal 

 motions of the film are also strikingly dis- 

 played. [See COLORS OF THIN PLATES; 

 FILMS; LIGHT.] TYNDALL Lectures on 

 Light, lect. 2, p. 67. (A., 1898.) 



3135. SOCIABILITY A PROTECTION 



Gregarious Mammals Dominate the World 

 Cooperation and Sympathy Begin in the 

 Lower Realm. Run over the names of the 

 commoner or more dominant mammals, and 

 it will be found that they are those which 

 have at least a measure of sociability. The 

 cat tribe excepted, nearly all live together in 

 herds or troops the elephant, for instance, 

 the buffalo, deer, antelope, wild goat, sheep, 

 wolf, jackal, reindeer, hippopotamus, zebra, 

 hyena, and seal. These are mammals, ob- 

 serve an association of sociability in its 

 highest developments with reproductive 

 specialization. Cases undoubtedly exist 

 where the sociability may not be referable 

 primarily to this function; but in most the 

 chief cooperations are centered in love. So 

 advantageous are all forms of mutual serv- 

 ice that the question may be fairly asked 

 whether after all cooperation and sympathy 

 at first instinctive, afterwards reasoned 

 are not the greatest facts even in organic 

 Nature? DRUMMOND Ascent of Man, ch. 7, 

 p. 238. (J. P., 1900.) 



3136. SOCIETY, MAN DEPENDENT 



ON Man in himself is a defenseless, help- 

 less creature. No other animal continues so 

 long in a state of infancy, no other exists 

 so long before obtaining its teeth, no other 

 so long before it is able to stand, no other 

 arrives so late at puberty. Even his great- 

 est advantages, reason and speech, are but 

 germs that develop not spontaneously, but 

 only by means of external assistance, culti- 

 vation, and education. This necessity of 

 assistance and his numerous urgent wants 

 prove the natural destination of man for 

 social connections. BLUMENBACH Manual 

 of Natural History, 4, p. 35. 



3137. SOIL PILED UP BY WORMS 



Materials Digested into Fertility. 

 Worms have played a more important part 

 in the history of the world than most per- 

 sons would at first suppose. In almost all 

 humid countries they are extraordinarily 

 numerous, and for their size possess great 

 muscular power. In many parts of England 

 a weight of more than ten tons (10,516 kilo- 

 grams) of dry earth annually passes 

 through their bodies and is brought to the 

 surface on each acre of land; so that the 



whole superficial bed of vegetable mold 

 passes through their bodies in the course of 

 every few years. From the collapsing of the 

 old burrows the mold is in constant tho slow 

 movement, and the particles composing it 

 are thus rubbed together. By these means 

 fresh surfaces are continually exposed to the 

 action of the carbonic acid in the soil, and 

 of the humus acids which_appear to be still 

 more efficient in the decomposition of rocks. 

 The generation of the humus acids is prob- 

 ably hastened during the digestion of the 

 many half-decayed leaves which worms con- 

 sume. Thus the particles of earth, forming 

 the superficial mold, are subjected to condi- 

 tions eminently favorable for their decompo- 

 sition and disintegration. Moreover, the 

 particles of the softer rocks suffer some 

 amount of mechanical trituration in the 

 muscular gizzards of worms, in which small 

 stones serve as mill-stones. DARWIN For- 

 mation of Vegetable Mould, ch. 7, p. 89. 

 (Hum., 1887.) 



3138. SOILS, EXHAUSTION OF Ro- 

 tation of Crops Scientific Practise in Ad- 

 vance of Science. We know that a virgin 

 soil cropped for several years loses its pro- 

 ductive powers, and without artificial aid 

 becomes unfertile. For example, through 

 this exhaustion forty bushels of wheat per 

 acre have dwindled to seven. Rotation of 

 crops is an attempt to meet the problem, 

 and the four-course rotation of turnips, bar- 

 ley, clover, and wheat witnesses to the fact 

 that practise has been ahead of science in 

 this matter. NEWMAN Bacteria, ch. 5, p. 

 161. (G. P. P., 1899.) 



3139. SOILS FERTILIZED BY BAC- 

 TERIA Future Agriculturist Will Inoculate 

 His Fields with the Most Useful Germs. 

 Experiments which are now conducting seem 

 to indicate that there are great differences 

 in the vitality and nitrifying ability of dif- 

 ferent nitrobacteria. It is the present work 

 of the chemist to compare the activity of the 

 nitrifying organisms existing in the soils of 

 widely separated localities and to isolate, if 

 possible, those which show the highest quali- 

 ties. When this shall have been accom- 

 plished, the novel practise will be seen of 

 practical farmers inoculating their fields 

 with minute capillary tubes containing a 

 colorless liquid in almost an unweighably 

 small quantity, in which are found invisible 

 organisms by whose multiplication the fer- 

 tilities of broad acres are to be increased. 

 As the surgeon now prepares particles of 

 virus which, when inserted into the system, 

 produce immunity from contagious disease, 

 so the farmer, by a similar species of inocu- 

 lation, will render possible in his soil the 

 growth of organisms which will increase 

 the quantity and value of his crops. WILEY 

 Relations of Chemistry to Industrial Prog- 

 ress (Address at Purdue University, Lafay- 

 ette, Ind., May, 1896, p. 38). 



