Magnetic Influence of Solar Light. 385 



series of experiments now detailed, is distinctly and decid- 

 edly opposed to the theory of such influence. The follow- 

 ing Table exhibits in a condensed form the experimental 

 results obtained, and will shew at a glance, the evidence on 

 which the above inference is founded. I may premise that 

 the term differential of temperature is employed to indicate 

 the difference between the temperature before and that after 

 exposure, while differential of oscillation shews the differ- 

 ence of the durations of oscillation under the same circum- 

 stances. When the duration before exposure exceeds that 

 after it, the sign + is prefixed to the differential, when the 

 converse is the case, the sign — is employed. 



TABLE XV. 



Shewing General Results of Experiments on the Magnetic Influence of Solar 

 Light, transmitted through coloured media. 







o • 



a 



'a 





si 



o • 



S 



'3 





6 



Cylinde, 



Nature 

 Medium. 



H 



o 



sri 

 S 



<» 

 O 



o 

 Q 



6 

 Z 



Cylinde: 



Nature 

 Medium 



Diff. of Te 



Diff. of Os 



Remarks. 











Sea. 













Diam. of Cy- 



1 



A 



Glass. 



36° 



—0-4 



8 



H 



Silk. 



16° 



+0-8 



linder A,C,D,E, 



2 



B 



Do. 



18° 



—0-4 



9 



I 



Do. 



18° 



0.0 



F,H,I,L,M,N,= 

 0-05 In. Diam. 



3 



C 



Do. 



27° 



+1-5 



10 



K 



Do. 



29° 



+ 1.4 



4 



D 



Do. 



24° 



+0*8 



11 



L 



Do. 



39° 



+0-2 



of Cylinders B, 



5 



E 



Do. 



19° 



— 0-2 



12 



M 



Cloth. 



32° 



—0-2 



G,K,6 = 0-04- 



G 



F 



Silk. 



26° 



+2.4? 



13 



N 



Do. 



32° 



+0.2 



No. 6, very 

 doubtful. 



7 



G 



Do. 



22° 



—0-2 



14 



O 



Do. 



31° 



+0-4 



The very trifling departures from equality between the 

 duration of oscillations before and after exposure, as indi- 

 cated by the last column of differentials, in combination with 

 the circumstance that these departures are sometimes on 

 one side, sometimes on the other, shew very clearly that no 

 force, constant in its direction, could have acted upon the 

 testing apparatus, and the theory of the magnetism of solar 

 light which implies such a force must accordingly be finally 



3 D 



