511 



SCIENTIFIC SIDE-LIGHTS 



Parsimony 

 Past 



smell is thrown off from these substances in 

 the form of invisible and imponderable par- 

 ticles. If paper be tied in front of the nos- 

 trils of dogs, they cannot " track " game or 

 follow their masters by the sense of smell. 

 LADD Psychology, ch. 6, p. 100. (S., 1899.) 



2513. PARTNERSHIP OF HEAT AND 

 COLD Each in Turn Contributes to Purity of 

 Milk. While the heating process is of 

 course the essential feature of efficient pas- 

 teurization, it must not be forgotten that 

 rapid and thorough cooling is almost 

 equally important. . . . Pasteurization 

 differs from complete sterilization in that it 

 leaves behind a certain number of microbes 

 or their spores. Cooling inhibits the ger- 

 mination and growth of this organismal 

 residue. If after the heating process the 

 milk is cooled and kept in a refrigerator, it 

 will probably keep sweet from three to six 

 days, and may do so for three weeks. 

 NEWMAN Bacteria, ch. 6, p. 211. (G. P. P., 

 1899.) 



2514. PARTNERSHIPS IN THE VEGE- 

 TABLE KINGDOM Combination for Mutual 

 Advantage Not Parasitism. Bacterial life 

 in several ways is able to reclaim from the 

 atmosphere this free nitrogen, which would 

 otherwise be lost. The first method to which 

 reference may be made is that involving 

 symbiosis. This term signifies " a living to- 

 gether " of two different forms of life, gen- 

 erally for a specific purpose. It may be to 

 mutual advantage, a living for one another, 

 or it may be, by means of an interchange 

 of metabolism or products, finally to pro- 

 duce or obtain some remote chemical result. 

 . . . The partnerships between hermit 

 crabs and sea-anemones and the like are 

 sometimes defined by the term commensal- 

 ism (joint diet). Symbiosis and commen- 

 salism must be distinguished from parasi- 

 tism, which indicates that all the advantage 

 is on the side of the parasite, and noth- 

 ing but loss on the side of the host. The 

 distinction between symbiosis and commen- 

 sal ism cannot be rigid, but between these 

 conditions, which are advantageous to the 

 partners, and parasitism, there is an obvious 

 and radical difference. The example of 

 bacteriological symbiosis, with which we are 

 concerned here, is that partnership between 

 bacteria and some of the higher plants 

 (Leguminosce) for the purpose of fixing 

 nitrogen in the plant and in the surround- 

 ing soil. NEWMAN Bacteria, ch. 5, p. 162. 



(G. P. P., 1899.) 



2515. PASSAGE FROM ONE KINGDOM 

 TO ANOTHER IMPOSSIBLE Inorganic Shut 

 from, Organic ; Natural from Spiritual. The 

 passage from the natural world to the spiri- 

 tual world is hermetically sealed on the 

 natural side. The door from the inorganic 

 to the organic is shut, no mineral can open 

 it; so the door from the natural to the 

 spiritual is shut, and no man can open it. 

 This world of natural men is staked off 



from the spiritual world by barriers which 

 have never yet been crossed from within. 

 No organic change, no modification of en- 

 vironment, no mental energy, no moral ef- 

 fort, no evolution of character, no progress 

 of civilization can endow any single human 

 soul with the attribute of spiritual life. 

 The spiritual world is guarded from the 

 world next in order beneath it by a law of 

 biogenesis except a man_ be born again 

 . . . he cannot enter the Kingdom of 

 God. DRUMMOND Natural Law in the 

 Spiritual World, int., p. 64. (H. Al.) 



2516. PASSING OF UNSEEN HOSTS 



The Nocturnal Journeys of Birds. This 

 nocturnal journey of birds may also be 

 studied from lighthouses. On September 

 26, 1891, I visited the Bartholdi Statue of 

 the Goddess of Liberty, in New York Bay, 

 for this purpose. The weather was most 

 favorable. The first bird was observed at 

 eight o'clock, and for the succeeding two 

 hours others were constantly heard, tho 

 comparatively few were seen. At ten o'clock 

 it began to rain ; and almost simultaneously 

 there was a marked increase in the number 

 of birds about the light, and within a few 

 minutes there were hundreds where before 

 there was one, while the air was filled with 

 the calls of the passing host. From the 

 balcony which encircles the torch the scene 

 was impressive beyond description. We 

 seemed to have torn aside the veil which 

 shrouds the mysteries of the night, and with 

 the searching light exposed the secrets of 

 Nature. By far the larger number of birds 

 hurried onward; others hovered before us, 

 like humming-birds before a flower, then 

 flew swiftly by into the darkness; and 

 some, apparently blinded by the brilliant 

 rays, struck the statue slightly, or with suf- 

 ficient force to cause them to fall dead or 

 dying. At daybreak a few stragglers were 

 still winging their way southward, but be- 

 fore the sun rose the flight was over. 

 CHAPMAN Bird-Life, ch. 4, p. 57. (A., 

 1900.) 



2517. PAST A GUIDE FOR FUTURE 



Volcanic Eruptions Etna. However nat- 

 ural it may be that the force of running 

 water in numerous valleys, and of tides and 

 currents in many tracts of the sea, should 

 now be spent, it is by no means so easy 

 to explain why the violence of the earth- 

 quake and the fire of the volcano should 

 also have become locally extinct at suc- 

 cessive periods. We can look back to the 

 time when the marine strata, whereon the 

 great mass of Etna rests, had no existence; 

 and that time is extremely modern in the 

 earth's history. This alone affords ground 

 for anticipating that the eruptions of Etna 

 will one day cease. 



Nee qnae sulfureis ardet fornacibus Etna 



Ignea semper erit, neque enim fuit ignea semper, 



(OViD Meiam., lib. 15, 1. 340.) 

 [Nor JDtna, vomiting sulfureus fire, 

 Will ever belch; for sulfer will expire. 



Dryden^s Trans.~\ 



