46 



affected by natural electricity ; but no one more than 

 myself and my spiders." He had found, by repeated 

 observations, that the length of the spiders' threads cor- 

 responded with the electrical state of the atmosphere : 

 for in wet and stormy weather they were short, and 

 in fine weather were proportionally long. Now, as there 

 may exist other causes sufficiently powerful to act as 

 excitants, as well as a current of air, the question re- 

 mains as it was : besides, apart from an effect analo- 

 gous to electrical excitement, the modus operandi of a 

 current of air seems most obscure and perplexing. 



There can, we think, be no doubt naturally enter- 

 tertained on the subject, that spiders can project their 

 threads in motionless air, peculiarly circumstanced. A 

 ray of solar light, for instance, will do it ; and the insect 

 will, in this case, sometimes dart out a thread many 

 yards long, perfectly vertical ; and, with the velocity of 

 an arrow, and an ascent equally rapid, is lost in a twink- 

 ling to the eye of the observer. Mr. White has the 

 following remark : " Last summer one alighted on my 

 book as I was reading in the parlour, and running to 

 the top of the page, and shooting out a web, took its 

 departure from thence. But what I most wondered 

 at was, that it went off with considerable velocity, in 

 a place where no air was stirring, and I am sure I did 

 not assist it with my breath ; so that these little 

 crawlers seem to have, while mounting, some locomo- 

 tive power, without the use of wings, and move faster 

 than the air, in the air itself." This phenomenon it has 

 been our fortune frequently to observe. The pheno- 

 menon recorded by Mr. Blackwall on the 1st October, 

 1826, accompanied by "a profusion of shining lines," 

 was observed when there was " no wind stirring ;" and 

 accordingly Mr. Rennie noticed that a spider " can 

 produce a line when there was scarcely a breath of 



