The Dispersion and Absorption of Fnchsin 



13 



lengths, till in the violet there was again a whole band displace- 

 ment. 



This brings up the question of phase change. There was evi- 

 dently about half a band phase change in the blue-green, but in 

 the violet end the red fuchsin reflects like a transparent body, 



and it is likely that the difference of phase change between it 

 and the glass is zero. Pfluger has gone into this point very thor- 

 oughly, and says that from the experiments of Wernicke it is 

 safe to assume that the phase change by reflection from fuchsin 



"3 



