192 



NATURAL HISTORY. 



[CH. XI 



boscis, with the extremity of which it felt four 01 

 five spots of my skin. It would appear that it knows 

 where it can pierce through most easily, and reach 

 a large blood-vessel. Having selected a spot for its 

 operations, it soon causes the sufferer to feel its 

 sting." The fine point when magnified presents the 

 following formidable picture, of which some of the 



*N 



detached pieces seem admirably fitted for the gnat's 

 purpose and our annoyance. It is not however, the 

 introduction of these points, which, when combined, 

 are as much less in size than the finest needle, as 

 that is than a sword, that causes the irritation which, 

 when extended over the limb, has in some cases ren- 

 dered amputation necessary — the gnat introduces a 

 little liquid, for the purpose, as Reaumur conjectures, 

 of rendering our thick blood thin enough to be 

 sucked through its proboscis. To allay the effects 

 of this poison, there seems to be no better or readier 

 means than sweet-oil, which, if applied to the wound 

 within a few hours after it has been made, will re- 

 move the swelling, although when delayed five or 

 six hours it has no effect. 



