422 



Wright and Kreider — Relation between 



Table IN. 

 (a) Crystals grown over S-pole of the vertical bar magnet. 



Crystals. Excess by 



, ■ > , < , % of Dextro Remarks. 



No. Wt. No. Wt. by wt. 



, (Dextro.. .. 1*258 .. Laevo rather larger. 



'(Laevo.. .. 1*709 .. 0*451 42*4 Uricertain,0*333grm. 



. - . Excess if all this 

 counts as laevo = 

 0*117 grm. 

 2 j Dextro.. 30 2*040 .. 1*320 

 'l Laevo __ 64 0*720 34 739 All good size. Dex- 



o (Dextro.. 75 0*510 .. tro rather larger. 



•( Laevo.. 77 0*677 2 0*167 43*0 



. ] Dextro.. 58 0*350 10 0*107 



(Laevo.. 48 0*243 .. 59*0 



5 ( Dextro.. 23 1*610 2 0*129 5 of laevo crystals 



"(Laevo .. 21 1*481 .. 52*1 " large, remainder 



very small. 



6. Resultant rotation = — 0*5 47*2"] Crystals distinct but 



1. " " —0*1 494! small. Determined 



8. " " —0*03 49*8 [ by method given at 



9. " " —1*96 39*1 J end of this paper. 



(b) Crystals grown under the N-pole. 



10 { Dextro.. 34 0*450 .. All clear and beauti- 



l Laevo.. 42 0525 8 0*075 46*1 fully crystallized. 



,, ^ Dextro.. 18 0*880 _. ' Irregular in size. Un- 



'( Laevo.. 33 1*633 15 0*753 35*0 certain 045 grm. 



12. Resultant rotation = — 3*5 305 ] Crystals distinct but 



13. " *' —1*9 39*4! small. Determined 



14. " " —2*8 34*4 f by method given at 



15. " " —0*04 49*8 J end of the paper. 



Here again, especially in (5), a curious preponderance, this 

 time of laevo crystals, is noted : but providing the effect to be 

 sought for is that due to the direction of the magnetic whirl 

 the results in (a) and (b) are inconsistent, since in both cases 

 the direction of the lines of force and hence of the magnetic 

 whirl is the same. However, from what has been said in regard 

 to the difference of the structural and magnetic rotations, it is 

 evident that the sense of the resultant activity could not be 

 predicted. 



In order to test the effect of a more powerful magnetic 

 field a Jamin magnet was supported vertically, so that a thin 

 glass, flat-bottomed beaker having a diameter marked upon it, 

 could be symmetrically placed over the poles and the crystals 

 formed on each side of the dividing line be separately tested. 

 But the result of a large number of crops so far as the opti- 

 cal activity is concerned was disappointing. While an in- 

 creased effect might have been expected or at least a verifica- 

 tion of the experiments with the bar magnet, the results are 



