VOL. LII.] PHILOSOPHICAL TRANSACTIONS. Sf83 



Beccaria's observations on natural electricity, and on meteors, on which he has 

 made a prodigious number of experiments, many of them of a delicate nature, 

 do him a great deal of honour. 



The 7th letter, the ingenious author does me the honour to address to me. 

 In this letter he justly laments the calamities of war; more particularly as it in a 

 great degree prevents that correspondence between men of letters which contri- 

 butes so much to their mutual satisfaction, and on which the improvement of 

 science so much depends. The more particular purport of this letter, is to answer 

 some objections, which Mr. David Golden, of North America, published against 

 the former letters of our author. These relate more particularly to the imper- 

 meability of glass to the electric fluid, and to the explanation of the phenomena 

 of the experiment ofLeyden. Besides these, he gives us his idea of non- electrized 

 bodies electrized plus, as he does not approve of the idea generally received of the 

 accumulation of electricity. He mentions, that he has read Mr. Canton's me- 

 moir relating to electricity, with his observations on stormy clouds. He finds 

 many curious facts in that work; but thinks them not sufficient to make the de- 

 ductions Mi*. Canton has done, in favour of the doctrine of plus and minus. 

 M. du Tour of Riom has sent the Abbe Nollet a memoir, which he has likewise 

 been so kind as to send me, containing a review of these experiments, from 

 which he thinks it very easy to resolve all these phenomena on the doctrine of 

 simultaneous affluence and effluence of the electric matter. 



The 8th letter is addressed to M. de Romas, assessor to the presidial of 

 Nerac, and contains remarks on electrical kites; on Father Ammersin's manner 

 of preparing and using wood to insulate bodies, in making electrical experiments; 

 and some observations concerning the doctrine of simultaneous affluence and 

 effluence of the electric matter. M. de Romas, in flying his electrical kite, was 

 the first who used a cord composed of hemp and wire. This compounded cord 

 conducted the electricity of the clouds far more perfectly than a hempen cord 

 would do, even though it was wetted; and this cord being terminated by one of 

 dry silk, enabled the observer, by a proper management of the apparatus, to 

 make what experiments he thought proper, without danger to himself. The 

 Abbe Nollet however desires M. de Romas to be very cautious in making these 

 experiments, and not too much to confide in his silk lines; as the vastness of 

 the electrical matter in thunder-storms may overcome the property of the silk, 

 and even make it a conductor of electricity, and hazard the life of the observer. 

 The quantity of electricity brought by M. de Romas's kite from the clouds has 

 been so great, that on the 26th of August 1756, * the streams of fire were an 

 inch thick, and 10 feet long, which were conducted by the cord of the kite to 

 the non-electric bodies near it, and the report of which was equal to that of a 

 pistol.* If a stroke of this kind had gone through the body of M. de Romas, 



