( 340 ) 
Solution 10/,. 
Ay Ag Pa, Pwa, Psa, 
512 546 1.182 1.352 — 16.2 
524 556 Ley. 1.288 — 14.4 
512 549 1.167 1.352 — 17.7 
525 556 1487 1.283 — 13.9 
517 548 1.172 1.325 — 14.6 
543 572 1.068 1.195 — 12.1 
545 573 1.064 1.186 — 11.6 
542 570 1.076 1.200 — 11.8 
566 590 0.996 1.093 — 9.1 
578 603 0.947 1.043 — 9.1 
611 635 0.842 0.919 — 7.3 
Solution 40/). 
500 519 1.314 1.423 — 21.2 
647 661 0.770 0.307 — 7.0 
606 617 0.899 0.936 — 7.1 
541 558 1.128 1.204 — 14.6 
Solution 20/,. 
598 646 0.810 0.966 — 7.2 
520 597 0.969 1.309 — 16.2 
550 612 0.916 1.163 — 11.6 
072 625 0.872 1.068 — 9.2 
507 995 0.976 1.380 — 19.8 
531 601 0.954 1.252 — 14.1 
The results have been combined in the annexed figure, in which 
the rotation constant @s,, is represented as a function of the wave- 
length A. If we take into consideration that with the solutions of 
4 percent the accuracy becomes smaller, on account of which 
we must not attach too much importance to the two deviating 
results for 4, = 541 and 647, it appears that no distinct variation 
of the rotation constant @;, with the concentration can be demon- 
