GNAT. 
390 
gions where they are evolved, it can rarely fall to 
the lot of one in an hundred to taste blood once 
in its life. 
The inconveniences, and even torments, expe- 
rienced from these insects in some parts of the 
world are hardly to be conceived by those who in- 
habit the more favoured regions of the European 
continent. Instances have often been known to 
occur of persons whose faces or limbs have been 
thrown into such a severe inflammation as even to 
threaten the most serious consequences, 
A warm, rainy season, is most favourable to the 
evolution of Gnats, and, in such summers, parti- 
cular districts in most countries are occasionally 
pestered by their legions. In the Philosophical 
Transactions for the year I/67 we have an in- 
stance of this kind in the neighbourhood of Ox- 
ford^ communicated by the late learned Mr. 
Swinton of that University. 
' ’ Oxford, Nov. 15, 1766. 
“ The Gnats have been more numerous, as well 
as more noxious here, during the months of July, 
August, and September, 1766, than perhaps they 
were ever known before in the memory of man. 
So many myriads of them have sometimes occu- 
pied the same part of the atmosphere, in conti- 
guous bodies, that they have resembled a very 
black cloud, greatly darkened the air, and almost 
totally intercepted the solar rays. The repeated 
bites likewise of these malignant insects have 
been so severe, that the legs, arms, heads, and 
