4 Mr. Spence on the Ilallan Mode 



Verna, I forget which,) near Florence, the monks of which assured 

 him of its efficacy, and afterwards by an artist at Rome, who warmly 

 expatiated on the important advantage which it conferred on him of 

 being able to work in his studio with open windows, and yet free 

 from the personal annoyance of flies, and the equally great one of 

 their settling on his newly painted pictures. 



Furnished with these hints, my friend, whose practical good sense 

 and habit of observation turns every new fact to profit, lost no time 

 in having thread-nets made, and adapting them to his windows 

 (which, as in Italy generally, are what we call French windows, 

 opening interiorly, so as when thrown back to leave the whole space 

 free), with the completely satisfactory result already mentioned, and 

 this with the least possible expense, trouble, or inconvenience, the 

 cost of a thread-net being a mere trifle, and all that is necessary 

 being to fix it as soon as the flies begin to be troublesome, across the 

 outside opening of the window, where it neither intercepts the air 

 nor view, and where it is suff'ered to remain until the approach of 

 winter, and the consequent disappearance of the flies. It is not even 

 necessary to be at the expense of an actual net, for if small nails be 

 fixed all round the window-frame at the distance of about an inch 

 from each other, and threads be then stretched across both verti- 

 cally and horizontally, the apparatus will be equally effectual. 



Here, however, it is necessary to state a remarkable fact which 

 my friend discovered in the course of his observations, namely, that 

 for this plan of excluding flies to succeed, it is essential that the 

 light enter the room on one side of it only, for if there be a thorough 

 light either from an opposite or side window, the flies pass through 

 the net without scruple. This circumstance, though not at all ma- 

 terially lessening the value of the practice, as rooms are usually (or 

 may be) lighted from one side only, must yet be borne in mind in 

 investigating the subject. 



Before we proceed to speculate on any extraordinary fact, it is 

 essential to be certain of its accuracy, and not only did the result of 

 numerous minute inquiries which I made of my informant, who, 

 though no entomologist, is a very careful observer, convince me of 

 the correctness of his statements, but they have been since amply 

 confirmed in all points by other intelligent friends resident in Italy, 

 who inform me that they have repeatedly seen this mode of ex- 

 cluding flies adopted with perfect success. One of them added that 

 it is not even necessary to have a net, or threads arranged both ver- 

 tically and horizontally so as to resemble one, but that if threads 

 be stretched in a horizontal direction only, across tlie openings of 

 the windows, at the distance of about an inch from each other, this 



