177 



matter, and also by inaction of body, whether the result of natural 

 indolence, or, as was originally the case in the present instance, of 

 necessary confinement. 



Various other circumstances are enumerated by the author as fa- 

 vouring- the accumulation of fat; and various expedients pointed out 

 for obviating this morbid tendency, founded on the principles of di- 

 minishing the supply of nutriment, of increasing the tone of the sy- 

 stem, and stimulating it to greater activity. 



The reading of a paper, entitled, " Experimental Determination of 

 the Laws of Magneto-electric Induction in different masses of the 

 same Metal, and of its Intensity in different Metals," by Samuel 

 Hunter Christie, Esq. M.A. F.R.S., was commenced. 



March 7, 1833. 



JOHN WILLIAM LUBBOCK, Esq. M.A., V.P. and Treasurer, 

 in the Chair. 



The reading of Mr. Christie's paper was resumed and concluded. 



Mr. Faraday, in his valuable papers entitled " Experimental Re- 

 searches in Electricity," has advanced the proposition, that " when 

 metals of different kinds are equally subject, in every circumstance, 

 to magneto-electric induction, they exhibit exactly equal powers with 

 respect to the currents which either are formed or tend to form in 

 them and " that the same is probably the case in all other sub- 

 stances." The author not being satisfied with the conclusiveness of 

 the experiments adduced in support of this proposition, — in order to 

 determine its correctness, subjected different metals directly to the 

 same degree of magneto-electric excitation, in such a manner, that 

 the currents excited in them should be in opposite directions (as 

 was the case in Mr. Faradav's experiment), and also that these 

 opposing currents should have the same facility of transmission ; so 

 that the difference of their intensities, if any existed, might admit 

 of measurement. He then minutely describes the apparatus he con- 

 trived with this view, and which consisted of helices of copper and of 

 iron wire, covered with silk, each making sixty-five turns, but in op- 

 posite directions, and crossing each other alternately, and surround- 

 ing a cylinder of soft iron, which was rendered magnetic by the appli- 

 cation of the large magnet belonging to the Royal Society, which the 

 Council had placed at his disposal while engaged in these researches. 

 The result of the experiment showed that the force of the currents 

 from the copper helix considerably exceeded that from the iron helix, 

 and appeared to be even more than double. By a modification of the 

 apparatus, he found that the intensities of the currents in the two 

 wires were very accurately proportional to their conducting powers ; 

 and hence the uniformity of the results obtained by Mr. Faraday is 

 easily explicable. 



The next object of Mr. Christie was to determine the order of the 



o 2 



