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XXXI. Account of seme Electrical Erperiments ly M. De 

 Nelis, of JSlnlines hi the Netherlands: with on Extension of 

 thern. By George John Stnger, und Andrew Crosse, 

 Esqrs. Communicated by Mr. Singer. 



-L/URi"sG the Inst fifteen year's, M. De Nelis has devoted con- 

 siderable attention to the subject of electricity, which he states 

 he was led to study in consequence of a thunder storm, which 

 accidentaily struck his house whilst his family were assembled 

 round a table in the dining parlour. 



The experiments he has made are very numerous, and present 

 some facts of an interesting nature. The present account of them 

 is selected in part from his recent communications to Mr. Tilloch, 

 and partly from his cirrespondence with M. De la Metherie. 



The first experiments were made with hollow cylinders of 

 metal, open at top, and ])artly filled v;ith water. In the centre 

 of each cylinder a needle was insulated, by surrounding it with 

 v/ax in such a manner as to keep it at an e(|ual distance from 

 the sides of the cylinder, whilst a thin slip of lead, or a piece 

 of leaden wire attaclied to the lower end of the needle, was thus 

 kept in the axis of the cylhider, and with its point resting on the 

 bottom thereof. 



In this disposition of th.e apparatus the metallic cylinder was 

 connected with t!ie out'^ide of a large electrical battery, and the 

 circuit was completed by means of the discharger, by connecting 

 the internal coating of tiie battery with the upper end of the 

 needle ; tl^e charge consequently passed through the small leaden 

 wire, which was thus melted under water in tlie centre of a me- 

 tallic vessel. 



The effects produced by this experiment are, 1st, The needle 

 and })art of the water contained in the cylinder are projected 

 from it with considerable force; and, 2dlv, The cylinder itself 

 is expanded more or less in proportion to its power of resistance. 

 \'ery thin cylinders yield to the first explosion ; but thicker ones 

 require many repetitions of the experiment, and usually become 

 undulated on the surface, whilst they expand gradually": at each 

 explosion the expansion increases, and at length the cylinder is 

 cracked or burst open, 



M. De Nelis has employed cylinders of various metals, and 

 of different thickness ; some of wide and others of narrow bore. 

 In general the effect is greatest with those of narrow bore when 

 the thickness remains the same ; but in comparative exj)eriments 

 with diiTercnt metals and alloys, he did not find that their relative 

 resistance corresponded with the tenacity assigned to them in 

 the n>,ual tables. The alloys appeared to resist more than the 



Vol. 4(j. No. 201). 5^/;/. '1815. L simple 



