MOTIONS 01 INSECTS. 331 



with my microscope, I found them to be much of the 

 same form, looking most like to a flake of worsted pre- 

 pared to be spun ; though by what means they should 

 be generated or produced is not easily imagined : they 

 were of the same weight, or very little heavier than the 

 air; and 'tis not unlikely, but that those great white 

 clouds, that appear all the summer time, may be of the 

 same substance a ." So liable are even the wisest men to 

 error when, leaving fact and experiment, they follow 

 the guidance of fancy. Some French naturalists have 

 supposed that these Jtls de la Vierge, as they are called 

 in France, are composed of the cottony matter in which 

 the eggs of the Coccus of the vine (C. Vitis) are en- 

 veloped 5 . In a country abounding in vineyards this 

 supposition would not be absurd ; but in one like Britain, 

 in which the vine is confined to the fruit-garden, and 

 the Coccus seldom seen out of the conservatory, it will 

 not at all account for the phsenomenon. What will 

 you say, if I tell you that these webs (at least many 

 of them) are air-balloons and that the aeronauts are 



not 



" Lovers who may bestride the gossamer 

 That idles in the wanton summer air, 

 And yet not fall " 



but spiders, who long before Montgolfier, nay, ever 

 since the creation, have been in the habit of sailing 

 through the fields of ether in these air-light chariots ! 



a Microgr. 202. It has been objected to an excellent primitive 

 writer (Clemens Romanus), that lie believed the absurd fable of the 

 phoenix. But surely this may be allowed for in him, who was no 

 naturalist, when a scientific natural philosopher could believe that 

 the clouds arc made of spiders web ! 



b Latreille, Hist. Nat. xii. 088. 



