Bell, were referred to the consideration of the Committee on 

 the Hall, with power to act. 



Dr. R. E. Rogers exhihited the capacity of the Rumkorff coil 

 (as modified by Ritchie), for generating electricity of high ten- 

 sion and great volume. Dr. Rogers explained, by experiments 

 with a small but powerful electi'ical machine armed with a 

 wooden ring, in the hollow of which was concealed a solid wire 

 ring (not alluded to by the maker or describers of the machine), 

 how the volume of the common electrical machine can be in- 

 definite. y increased, without diminishing the tension, by simply 

 protecti.'ig its condenser from the air, which, even in its most 

 favourable conditions, cannot but occupy itself incessantly with 

 carrying off the electricity. Dr. Rogers succeeded in affording 

 such protection to the common condenser by simply making it 

 hollow, and facing the inside instead of the outside with a me- 

 tallic surface. The same result is obtained by insulating the 

 outside surface by means of a heavy coat of varnish. A silk 

 gown thrown over the operator standing on an insulating stool, 

 makes him a ])owcrful condenser, upon this pi'inciple. 



Slated Meeting, Februarij IS, 1859. 



Prof. Cresson, Vice-President, in the Chair. 



Present, thirteen members. 



Letters announcing donations for the library were read from 

 the I. R. Geol. Inst, dated Vienna, Nov. 30, 1857, Jan. 10, 

 1858;— the I. Soc. of Nat. of Moscow,-dated June 5-17, 1858; 

 —the R. Sax. Soc. dated Leipsig, April 28, and July 18,1858: 

 —the U. Hess. S. N. H. dated Giessen, Aug. 6, 1858:— the R. 

 Dan. S. dated Copenhagen July 1, 1858:— the R. A. S. at Am- 

 sterdam, dated Dec. 10, 1857, and June 23, 1858: and the 

 scientific commission of the Zool. Gard. of Amsterdam, dated 

 March, 1858. 



Letters were also read from the R. A. S. at Amsterdam, ac- 

 knowledging the receipt of the Society's publications: — from 

 Dr. D. Bierens de Haar, calling the favourable attention of the 



