45 



Mahomet's spider, which insured the safety of the 

 flight of the prophet of Mecca. 



Even on the supposition that such a current is 

 essential and necessary, it can only be regarded as 

 an exciting cause, rousing the insect, or imparting the 

 power to evolve its thread. The most interesting 

 part of the question is, whether it acts in a merely 

 mechanical capacity, or whether this excitement 

 be something more, and connected with a power su- 

 perior to what these views suppose. Bennet and 

 other electricians have long ago proved, that the im- 

 pulse of air on a delicate electroscope invested it 

 with electricity ; and this, if proved in the one case, 

 must of necessity be admitted in the other. In the 

 Mediterranean, Mr. Black appears to have ascertained 

 that winds, or currents of vapour of some continu- 

 ance, are negatively electrical, and the land breeze 

 in a state of positive electricity. It seems deducible, 

 therefore, that an electrical excitement may be the 

 consequence of such currents ; and it seems equally 

 obvious that insects are sufficiently sensible to atmo- 

 spherical electricity. Thus Huber seems to have 

 proved, that the secretion of honey is intimately con- 

 nected with electricity ; and that bees are far more 

 active and laborious before a storm, and when the wind 

 is south and the air warm and humid, than at other 

 times : and Kirby and Spence also observe, that " in- 

 sects seem particularly excited by a high electric state 

 of the atmosphere, and are then found more numerous 

 on the wing than at ordinary periods, and towards 

 evening ; and that, some time before the storm comes on, 

 various kinds may be then seen, that do not appear at 

 ordinary times : but immediately before the storm, all 

 disappear."* DTsjonval observes, that " animals are 



* The extraordinary activity of the sw allow on these occasions 

 is a manifest proof. 



