Intellis;ence and Miscellanies. 399 



'6 



with other crystals, and each halo will be either double when 

 the refraction is considerable, or modified by various colors, 

 when the refraction is weak. The eflects may be varied in a 

 curious manner, by crystallizing on the same piece of glass, 

 salts of a determinate color. By this means, halos white and 

 colored succeed each other. — Bulletin teclmilogiqice Aout, 

 —1828. 



63. Corrosive Sublimate. — At the common temperature, 

 four parts of ether dissolve one part of corrosive sublimate ; 

 but by taking equal parts of camphor and sublimate, it re- 

 quires but three parts of ether for solution. By increasing 

 the proportion of the camphor, we have the following results : 

 4 parts of ether with 4 of camphor, dissolve 2 parts of sublimate. 

 4 " " " g u "4 " u 



4 " 't "16 " " 8 " " 



3 parts alcohol, common temperature, dissolve 1 part of sub- 

 limate ; in adding to the latter, only the half of its weight of 

 camphor, one and a half part of alcohol is sufficient for the 

 solution. — Fev. Bui. Mars. 1818. 



64. On the Gossamer Spider, by Mr. Bowman. — Several 

 of these httle insects were arrested in their flight, and placed 

 upon the brass gnomon of a sun-dial : in a short time they 

 prepared for their aerial voyage. Having crawled about to 

 reconnoitre, they at last turned their abdomens from the cur- 

 rent of air, and elevated them almost perpendicularly, suo- 

 porting themselves solely on the claws of their fore legs ; at 

 the same instant shooting out four or five, often six or" eight, 

 extremely fine webs, several yards long, which waved in the 

 breeze, diverging from each other like a pencil of rays, and 

 strongly reflecting the sunbeams. After the insects had re- 

 mained stationary in this apparently unnatural position for 

 about half a minute, they sprung off" from the stage with 

 considerable agility, and launched themselves into the air. 

 In a few seconds after, they were seen sailing majestically 

 along, without any apparent effort ; their legs contracted 

 together, and lying perfectly quiet on their backs, suspended 

 from their silken parachutes, and presenting to the lover of na- 

 ture afar more interesting spectacle than the balloon of the 

 philosopher. " One of these natural aeronauts I followed," 

 says Mr. Bowman, " which, sailing in the sunbeams, had two. 



