Makch 9, 1906.] 



SCIENCE. 



391 



refractivity imbedded in the lens would come 

 nearest. Such a bubble would replace a con- 

 cave lens in front of the eye, and the rays 

 brought more nearly to a focus would leave a 

 deficiency around the area of convergence. 

 Possibly the images in the preceding para- 

 graph may be explained in the same way. 



3. A third phenomenon is probably quite 

 well known, though I must here also confess 

 my ign«rance. The diffuse and faint (false) 

 corona which most people see around a dis- 

 tant point source, changes to an intensely 

 brilliant and narrow colored ring with the 

 blue packed close upon the red, whenever the 

 pupil is opemed by belladonna. That no true 

 (objective) corona is in question may be 

 proved at once by blotting out the point source 

 with the sharp end of a pin, whereupon the 

 phenomenon vanishes completely, although the 

 region in which the corona was localized is 

 still almost wholly visible. As the effect of 

 the stimulus subsides the aperture of the red 

 annulus, which is about 7 degrees in the bril- 

 liant and narrow state, with all colors close 

 together, expands to about 9.5 degrees for the 

 faint and diffuse case with the colors far 

 apart, during the three or four days of con- 

 traction of the pupil. 



The observation here in question is not lack- 

 ing in interest for the physicist; yet I have 

 often been provoked at not finding any allu- 

 sion to such an obtrusive phenomenon in the 

 treatises on optics with which I happen to be 

 acquainted. 



Carl Barus. 



Brown Univeesitt, 

 Providence, R. I. 



PRESERVING SPIDERS' WEBS. 



Spiders' webs are so interesting in them- 

 selves and each web is so characteristic of the 

 particular species to which its maker belongs 

 that their study is one of the most fascinating 

 of natural history pursuits. However, if I 

 am not mistaken, it is not generally known 

 that they can be easily and permanently pre- 

 served for future study or display. One 

 method of doing this occurred to me several 

 years ago while watching Mr. Jas. H. Emerton 

 spraying webs for photographing, and I have 



since used it so successfully that it seems 

 worth deseribing. 



The web to be preserved is sprayed with 

 artist's shellac from an atomizer, in much the 

 same way that crayon drawings are fixed, and 

 immediately a clean glass plate is pressed 

 against it, carefully breaking, at the same 

 time, the supporting strands so that the web, 

 which will stick to the glass, is freed from its 

 former surroundings. Since every strand of 

 the web is covered with minute droplets of 

 shellac, they are rendered plainly visible and, 

 furthermore, they adhere very tightly to the 

 glass. In a short time the shellac will thor- 

 oughly dry and the plates holding the webs 

 can be filed away in a cabinet or hung up for 

 display. If desired, the web may be protected 

 by covering it with another glass plate in the 

 way that the film of a lantern slide is pro- 

 tected, but this is not usually necessary. 



The above directions apply paticularly to 

 the flat webs of the Epeiridse, but with a little 

 ingenuity almost any spider's web may be 

 preserved in its natural form. For instance, 

 I obtained a permanent mount of the dome- 

 shaped web of Linyphia marginata in the fol- 

 lowing way: A branched twig was cut and 

 stripped of its leaves. This was fastened in 

 an upright position on a suitable base and 

 several females of L. marginata put on it after 

 sunset. The next morning I had a beautiful 

 web with a perfect dome and all the outlying 

 threads. The only thing that remained to be 

 done was to spray it with shellac and set it 

 away. The Therididse also give very satisfac- 

 tory specimens in much the same way. But 

 for the orb webs I think the glass plates are 

 preferable. 



Frank E. Lutz. 



Station fob Experimental Evolution, 

 Cold Spring Harbor, L. I. 



A NEW METEORITE FROM SCOTT COUNTY, KANSAS. 



A HITHERTO unreported meteorite fall took 

 place on the night of September 2, 1905, about 

 9:30 P.M., in Scott County, Kansas. The fall 

 was attended with the usual explosion, light 

 and sound, variously compared to cannonading 

 and the roll of heavy wagons. 



Thus far fourteen pieces of the stone have 



