smelled strongly of sulphur. In making them, he received a stroke on his arm a little below the elbow; but he could not tell whether it came from the brass wire inserted into the phial, or from the bar. He did not attend to it at the time; but the pain continuing, he uncovered his arm when he went home, in the presence of Coissier. A mark was perceived round it, such as might have been made by a blow with the wire on his naked skin. Although it appears from the foregoing statement, that the directions of Dr. Franklin began to be put in execution in France, he himself completed the demonstration of his own problem, before he heard of what was done elsewhere. An account of these experiments will be found in the scientific part of this work. Since the time of Franklin, there has been no capital discovery in electricity:—at least, no discovery of such a nature as to demand a detailed account in this portion of our work. Experiments and improvements have been made; and numerous electricians have evinced a very commendable diligence in the cultivation of this department of knowledge. But their exertions have been directed to the reason and philosophy of the phenomena already known, to the classification of the facts, and to the improvement of the apparatus. Thus Mr. Canton has given a very curious set of experiments upon the conducting power of air, to ascertain wherein consists the distinction between the bodies which are conductors, and those which are not. Signor Beccaria, also, with the same view, experimented upon water and smoke. But what more properly belongs to history, is to mention the view, which Mr. Æpinus, of the Imperial Academy of St. Petersburgh, in the year 1759, took of the science of electricity. This gentleman, struck with the resemblance of the electrical properties of the tourmaline to the properties of a magnet, which have always been considered as the subject of mathematical discussion, fortunately remarked a wonderful similarity in the whole series of electrical and magnetical attractions and repulsions, and set himself seriously to the classification of them. Having done this with great success, and having maturely reflected on Dr. Franklin’s happy thought of plus and minus electricity, and his consequent theory of the Leyden phial, he at last hit on a mode of considering the whole subject of magnetism and electricity, which bids fair for leading to a full explanation of all the phenomena; at least, as far as to enable us to class them with precision, and to predict what will be the result of any proposed treatment. The work containing this hypothesis, was published at Petersburgh, under the title of _Theoria Electritatis et Magnetismi_, and is pronounced to be “one of the most ingenious and brilliant performances of the last century.” A summary view of this theory, and the principles on which it is formed, will be seen in the course of the ensuing work.