188 Dr. S. J. Lewis. Ultra-Violet Absolution Spectra and 



Table VII. — Comparative Observations on the Eesults. 





Amplitude. 



A. for bead. 



A. for foot. 



Pseudo-globulin — 



0-72 









2790 



2520 





0-72 



2790 



2521 



Alean 



72 



2790 



2521 



Eu-globulin — 











53 



2775 



2532 





0-66 



2795 



2530 





0-60 



2785 



2531 



Albumin — 











0-36 



2785 



2545 





0-23 



2783 



2540 





0-30 



2784 



2543 



identity of the wave-lengths signifies the close similarity of chemical 

 constitution for the three proteins, while the small differences, which are 

 well substantiated so far as the present series of experiments goes, may 

 possibly be significant of differences in the nature of the subsidiary groups 

 present in the respective molecules. On the other hand, the amplitudes, 

 which are respectively 072, - 60 and - 30, reveal differences which are too 

 great to be lightly set aside. 



It remains, then, that it is mainly in the magnitude of the extinction 

 coefficients that the differences among these three proteins find expression. 

 This has already received some attention in the comparison of eu-globulin 

 with pseudo-globulin ; but, with albumin, the divergence from the apparently 

 well-defined pseudo-globulin is much greater, and not of quite the same 

 order ; and, further, there is no doubt as to horse albumin being quanti- 

 tatively distinct from human albumin. 



If the ratio of the adopted extinction coefficients for the two varieties of 

 albumin be taken, we get 



Head of band. Foot of band. Amplitude. 



Horse 1-20 _ vrj Q-84 -..oh 0'36 _ i. 57 



Human 0-68 0"45 023 



or, if the figures for the two specimens of human albumin from "normal" 

 serum alone be taken, we get 



0-68 - 1 77 0T8 - 1 75 0-20 _18U 



