FRAGMENTS OF SCIENCE. 



569 



to use a field glass or small telescope, and, 

 having once found the birds with it, to keep 

 them in the field as long as possible. . . . 

 Up and up they go, appearing smaller each 

 moment till even the power of the glass is 

 overcome, and the tiny specks vanish for the 

 night. As you drop your arms wearily you 

 find that the dusk has fallen, the bats are 

 out, and the evening mists are rising ; but 

 the swifts must now be nearly on a level 

 with those remote flecks of cloud which, at 

 an immense height, are yet snowy in the sun- 

 shine." 



The Light of Fireflies. In experiments 

 on the properties of the light of fireflies, Prof. 

 H. Muraoka used plates of copper, aluminum, 

 zinc, and brass of equal size, separated from 

 the photographic plates on which they were 

 severally laid by a layer of cardboard having 

 a cross-shaped piece cut out of the center ; 

 wrapped the whole with three or four thick- 

 nesses of black paper, and exposed the 

 bundle to the light of several hundred fire- 

 flies. His purpose was to learn whether 

 the light from the insects after filtration 

 through the black paper could penetrate the 

 metals and affect the photographic plate, 

 and to determine the relative transparency 

 of the substances used. To his surprise, the 

 parts of the photographic plate under the 

 cardboard were most darkened, while those 

 under the cross-shaped holes remained clear. 

 The light of the insects seemed to behave 

 very much like ordinary light, but, after 

 *' filtration," acquired properties similar to 

 those of the Rontgen or the Becquerel flu- 

 orescent rays properties apparently result- 

 ing from the filtration. Further, the filtered 

 rays appeared to exert a peculiar action to- 

 ward the cardboard called by the author a 

 suction phenomenon similar to that of the 

 lines of magnetic force upon iron. The prop- 

 erties of the filtered rays seemed to depend 

 on the filtering substances, probably upon 

 their thickness. They exhibited properties 

 of reflection, but those of refraction, inter- 

 ference, and polarization were not observed, 

 although the author believes that they exist. 

 Their properties, generally, appear to be be- 

 tween those of the ultra-violet and the 

 Rontgen rays. The insects used in the ex- 

 periments had two or three rows of luminous 

 spots on their under body ; but the photo- 



graphic plates were affected by the whole 

 body as well as by the luminous spots, so 

 that a complete image of the insect was 

 formed when it was put upon the plate, the 

 figure of the luminous part being, however, 

 plainer than the rest. 



Dust. Micro-organisms are the great 

 producers of disease, and dust is the chief 

 carrier of micro-organisms. If there is any 

 one ubiquitous thing, it is dust, and yet, not- 

 withstanding its dangerous contents, it is 

 being continually poked up, so to speak. 

 As soon as the housemaid is up, it is hustled 

 and dusted into the air, so that by the time 

 the family is astir any germ which may have 

 quietly settled in some corner where it could 

 do no harm is fioating about in the air, ready 

 to appropriate any convenient and moist rest- 

 ing place, such as the human lungs or a bit 

 of the breakfast, which will shortly carry 

 it into one of the inmate's systems. The 

 street-cleaning department, too, spends much 

 of its energy in simply stirring up the dust 

 about the streets ; a little of it is carried off 

 in carts each day, but every particle thus re- 

 moved has probably been previously stirred 

 up and allowed to settle a dozen times. The 

 carpets and upholstery of modern houses 

 were apparently designed as dust collectors. 

 It is impofsible to clean thoroughly a thick- 

 ly upholstered sofa or chair, and almost aa 

 difiicult to get a modern carpet or rug clean ; 

 these articles always contain more or less 

 dirt, which in the case of the carpet is super- 

 ficially stirred up at each sweeping. In fact, 

 the reckless way in which house and street 

 cleaning are handled is really appalling. 

 Dusting should always be done with a damp 

 cloth, and carpets cleaned by a closed sweeper 

 well filled with wet tea leaves. The street- 

 cleaning problem is simply a question of 

 water supply. A thorough flushing of the 

 streets once or twice in twenty-four hours 

 offers a simple hygienic and thorough solu- 

 tion. 



Pocltet Gophers. The pocket gophers, 

 or Oeomyidce, according to G. Hart Mer- 

 riam's description, are North American ani- 

 mals exclusively, and most at home in the 

 western United States and Mexico. Their 

 whole organization is modified to suit a life 

 underground. They are short-legged, thick- 



