199 



The general conclusions to which he is led from the experiments 

 detailed in this paper are the following : — First, that all bodies con- 

 duct electricity in the same manner, but in very different degrees; — 

 Secondly, that in some the conducting power is powerfully increased 

 by heat, in others diminished, and this without any difference that 

 has yet been discovered, either in the general nature of the substance, 

 or of the influence of electricity upon it; — Thirdly, that there is a 

 numerous class of bodies which, when solid, insulate electricity, and, 

 when fluid, conduct it freely, and are decomposed by it ; yet that 

 there are many fluid bodies which do not sensibly conduct electricity 

 of low intensity ; and some that conduct it, and are not decomposed ; 

 — and, Lastly, that fluidity is not essential to decomposition. Sul- 

 phuret of silver is the only body yet known to be capable of insu- 

 lating a voltaic current when solid, and of conducting it, without de- 

 composition, when fluid. No distinction can as yet be drawn between 

 the conducting powers of bodies supposed to be elementary and those 

 known to be compounds. 



The Society then adjourned over Whitsun-vveek to the 6th of June. 



June 6, 1833. 



FRANCIS BAILY, Esq., Vice-President, in the Chair. 

 Captain John Lihou, R.N., was elected a Fellow of the Society. 



Professor Desfontaines, of Paris j Professor C. G. J. Jacobi, of 

 Konigsberg ; Baron von Lindenau, of Gotha ; Professor Meckel, of 

 Halle; and M. G. de Pontecoulant, of Paris, were elected Foreign 

 Members of the Society. 



A paper was read, entitled, " An Account of a Second Series of 

 Experiments on the Resistance of Fluids to Bodies passing through 

 them." By James Walker, Esq., F.R.S., Civil Engineer. 



The author, in a paper read to the Society in the year 1827, and 

 printed in the Philosophical Transactions, gave an account of some 

 experiments showing that the resistance of fluids increases in a ratio 

 considerably higher than the square of the velocity, and that the ab- 

 solute resistance is smaller than had been deduced from the experi- 

 ments of the French Academy. In the present communication he 

 states the results of his further inquiries on this subject. His expe- 

 riments were made at the East India Docks, on a boat twenty-three 

 feet long and six wide, with the stem and stern nearly vertical ; one 

 end being terminated by an angle of 42°, and the other of 72° ; and 

 the resistance to the boat's motion being measured by a dynamome- 

 ter. The results are given in tables : and it appears from them, that 

 in light vessels sharpness is more important in the bow than in the 

 stern - } but that the reverse is the case in vessels carrying heavy car- 

 goes. From another series of experiments the author infers that the 

 resistance to a flat surface does not exceed 1 '25 lb. for each square 



