Chemistry and Physics. 



323 



to be useful for other purposes, such as examining the passage of 

 light through solutions at rest or in motion. 



The apparatus, as shown in the accompanying figures, con- 

 sisted of a refractometer in which each half-beam went out and 

 back by different paths. The paths of one half-beam were 

 between two iron disks one centimeter apart which could be 

 rotated in either direction and magnetized by the observer while 





mi 









1 





m 4 



X 



Fig. 2. Refractometer and Revolving Magnets. 



examining the fringes in the telescope. A shift of the fringes 

 was observed, but it was impossible to estimate how large a factor 

 instrumental errors were in the result. It is proposed to repeat 

 the experiments later with better apparatus. 



15. On the Presence of Gallium in the iSun. An investigation 

 has recently been published by W. N. Hartley and Hugh 

 Ramage, in the Scientific Transactions of the Royal Dublin 

 Society (Volume vii), on the wave-lengths of the principal 

 lines of the spectrum of gallium. The values obtained for 

 the two prominent lines are 4172*214 and 4033-125. These 

 measurements were made on the reversed lines obtained with an 

 arc spectrum of iron containing a large proportion of the residue 

 from ignition of gallium ferrocyanide. Atter a minute examina- 

 tion of the solar spectrum, the conclusion is reached that this 

 element, which has been shown by the same authors to be 

 widely distributed in minute quantities in the crust of the earth, 

 to be present in the pumice and volcanic dust from New Zealand 

 and Krakatoa and associated with nickel and cobalt in iron 

 meteorites, is also present in the sun. The solar lines determined 



