418 PHILOSOPHICAL TRANSACTIONS. [aNNO 1759. 



a fluid matter, extremely subtile, constitutes electricity. On this principle he 

 endeavours to account for all the phenomena that attend the electrification of 

 bodies. 



What M. Nollet has obser\^ed with regard to two contrary currents in electri- 

 city, is by no means inconsistent with the principle of two distinct counteracting 

 powers. On the contrary, the existence of two such currents is, according to 

 Mr. S.'s opinion, a necessary consequence of the exertion of those powers from 

 one body on another. It is a phenomenon of electricity only ; not the principle 

 on \vhich all electrical appearances depend. But a more essential difference takes 

 place between this gentleman's opinion and Mr. S.'s : he represents the two cur- 

 rents as consisting but of one and the same fluid; admits but of one kind of 

 electricity ; and maintains that two bodies cannot be said to be diff^erently elec- 

 trified, but as they are electrified in a higher or lower degree. On the other 

 hand, it is Mr. S.'s opinion, that there are two electrical fluids (or emanations 

 of two distinct electrical powers) essentially different from each other; that elec- 

 tricity does not consist in the efliux and afflux of those fluids, but in the accu- 

 mulation of the one or the other in the body electrified; or, in other words, it 

 consists in the possession of a larger portion of the one or of the other power, 

 than is requisite to maintain an even balance within the body ; and lastly, that 

 according as the one or the other power prevails, the body is electrified in one or 

 in another manner. 



071 the Force of Electrical Cohesion. By Dr. John Mitchell, p. SQO. 



Dr. M. happening to be at Mr. Symmer's, he desired him to be witness to some 

 electrical experiments he was about to make with silk stockings, of a particular 

 kind, which he had received for that purpose. The weather was then remark- 

 ably favourable for electricity, being clear and dry, with a sharp frost, which had 

 continued 5 or 6 days. The wind was easterly, and had been in that quarter for 

 10 days. It was about noon when we made our experiments: the barometer at 

 30, and Fahrenheit's thermometer at 32. 



The stockings above-mentioned were wove of carded and spun silk, and were 

 more substantial and weighty than those with which he had made the experi- 

 ments mentioned in his 3d paper. One pair was of a deep black, having been 

 twice dyed, to improve the colour. Another pair was of the natural colour of 

 the silk, of a dusky white, and both new. The pair of black weighed 4 oz. 8 

 dvvt. 4 gr., and the white 3 oz. 18 dwt. 15 gr. 



They began with making a few experiments with the thin stockings formerly 

 used: and found the result to be much the same with what is related by Mr. 

 Symmer in his 3d paper; that is, that when the white stocking was put within 

 the black, or vice vers^, and both highly electrified, taking hold of the one^ 



