362 Prof. H. E. Armstrong and Mr. E. Horton. [Mar. 3, 



We are of opinion that the change indicated in these various cases is in tlie 

 direction corresponding with the conversion from /S- into «-glucose, not from 

 « into yS. But this change is complicated hy some change in the other substances 

 present in the solution which somewhat masks that undergone by the glucose. 



The complete set of readings ol)tained in the course of another experiment 

 may be given with advantage, as illustrating the procedure and also because 

 of the evidence they afford that changes are proceeding such as have been 

 referred to. The equilibration of the glucose by means of the alkali added 

 (1 drop of a ION solution) is practically an instantaneous process. It should 

 be mentioned that the set of readings given on each of the lines in the table 

 would occupy about five to six minutes, readings being taken at intervals of 

 about half a minute. 



Time. 



Polarimeter readings. 



Mean 

 rotation. 



Change in 

 rotation. 



1 



1 



2 

 3 

 4 

 5 

 6 

 24 



hour . . . 

 "5 hours 



f Initial 

 1 + alkali 

 / Initial 

 1 + alkali 

 J Initial 

 1 + alkali 

 f Initial 

 \ + alkali 

 J luitinl 

 1 + alkali 

 Initial 

 + alkali 

 f Initial 

 \ + alkali 

 r Initial 

 1 + alkali 



-4° -20, 21, 

 -4° -18, 20, 

 -3° -96, 97, 

 -3° -91, 90, 

 -3° -69, 69, 

 -3° -64, 64, 

 -2° -77, 78, 

 -2° -77, 80, 

 -2" -59, 55, 

 -2^-60, 60, 

 -2° -08, 07, 

 -2° -07, 13, 

 -l°-44, 43, 

 -l°-48, 52, 

 + 0°-56, 54, 

 + 0"-48, 40, 



23, 23, 

 17, 21, 

 96, 95, 

 94, 94, 

 69, 67, 

 68, 69, 

 79, 78, 

 82, 87, 

 60, 55, 

 00, 58, 

 08, 11, 

 08, 24, 

 44, 43, 

 52, 54, 

 56, 55, 

 42, 42, 



20, 22, 

 14, 13, 

 95, 94, 

 93, 93, 

 70, 66. 

 67, 67, 

 79, 82, 

 84, 85, 

 57, 58, 

 61, 63, 

 10, 11, 

 24, 18, 

 46, 46, 

 53, 54, 

 i)4, 55, 

 41, 40, 



23, 20, 



18, 18, 



95, 96, 



89, 89, 



68, 69, 



67, 67, 



83, 80, 



87, 89, 



58, 57, 



67, 66, 



10, 08, 



20, 24, 



45, 45, 



57, 58, 



56, 56, 



42, 40, 



23, 22 

 17, 14 

 94, 95 

 94, 89 

 68, 68 

 67, 67 

 81, 81 

 85, 89 

 57, 58 

 67, 70 

 10, 11 

 21, 23 

 47, 46 

 55, 55 

 55, 55 

 41, 40 



+ 0° -05 



+ 0°04 



+ 0° -01 



-4° -221 

 -4° -17 [ 

 -3° -95 1 

 -3"" -91 / 

 -3" -68 1 

 - 3° -67 / 

 -2° -80 11 _ 

 -2° -84;: ^ 

 -2° -57 \ ' 

 -2° •63/ 

 -2= -09 1 

 -2°-18 / 



04- 



0°-06 



-0°-09 



■l°-54/l 

 + 0° -55 1 ' 

 + 0° -41 / 



■09 



0'-14 



The figures given in the last column are obtained from the mean rotations 

 before and after the addition of alkali. If, liowevcr, the first reading after 

 the addition of alkali be compared with the last prior to the addition — thus 

 reducing the possible change of the enzyme to a minimum — the changes in 

 rotation become +0°-04, +0°-04, +0°-04, +0°-04, -0°-02, +0°-04, -0°-02, 

 and — 0°'O7 respectively, values whic.li lend still more support to tlie (loncilusion 

 that the glucose is liberated in the (3-Utiu\. Moreover, the ol)servation in all 

 three experiments of a comparatively large change produced by adding alkali 

 to the 24-liour sample, when i)rcsunial)lyall tlie glucose isprescnt as une(|uilibi a- 

 ted mixture, is evidence that tlu; enzyme suffers a change (in optical rotatory 

 IKjwer) in a direction contrary to that undergone l>y the liberated glucose. 



Comparative Action of Ewnhiii, and of the J'haseolus Enzyme on Fixeher's 

 (llucmi(fe,Aiii ii(i(l(iliv and / Ii r J'/i (ifsco/ns Gliiroslde. — Assuming that the resolution 



