268 J. II Long — Circular Polarization of 



tie. The salt is readily soluble. The results of the tests are 

 shown in tabular form. 



gm. in 100 cc. D* 4 ° P a [a] 



5 gm. TlNaC 4 H 4 6 



.4H 9 0.. 



1-0317 



4-8379 



1-810 



9-065 



10 " il 





10652 



9-3710 



3-075 



7-701 



15 :1 







1-0992 



13-623 



4-188 



6-992 



•20 '• " " 







1-1311 



17-651 



5-186 



6-492 



A marked decrease in the specific rotation by increase of 

 concentration is shown. This is best illustrated by a curve ob- 

 tained by plotting the concentrations as abscissas and the spe- 

 cific rotations as ordinates, which will be found below. 



In order to find the effect of change of temperature I pre- 

 pared a solution containing 10 gm of the anhydrous salt in 100 cc . 



Direct tests gave 



a 184 =3°-362 a 28 =3°-780 



D 1 / = 1-0791 D 3 4 °= 1-0741 



from which were calculated 



[a] 20 = 8°-595 

 [«] 88 9°-490 



we have here an increase of over 10 per cent for only 8° of 

 temperature, which is somewhat remarkable. 



The influence of the presence of inactive salts was shown by 

 testing three solutions at 20°. One containing in 100 cc 10 gm of 

 the tartrate and 5 gm of sodium sulphate (anhyd.) gave [a\ = 

 10 o, 192 ; the second containing 10 gm of the tartrate and 5 gm of 

 thallium sulphate gave \a~\ — 5°-494 ; while the third, made by 

 mixing equal volumes of the other two, gave [a\ = 8° -139. 



Thallium Lithium Tartrate, TlLiC 4 H 4 6 . H 2 0. 



This salt was prepared from pure thallium bitartrate and 

 lithium carbonate, and was readily obtained in large crystals 

 which were found by analysis to possess the above formula. 

 Four solutions were tested, the results given in the table below 

 show a great similarity between the behavior of this salt and 

 that of the preceding one, which is likewise indicated by a 

 curve, plotted as before. 



gm. in lOOcc. D* 4 ° P a [a] 



5 gm. TlLiC 4 H 4 6 .HoO 



1-0347 



4-8150 



1-888 



9-456 



10 " " " 



1-0744 



9-2910 



3-114 



7-799 



15 " " " 



1-1107 



13-480 



4-276 



7-139 



20 " " " 



1-1467 



17-410 



5-345 



6693 



A solution containing 10 gm of the tartrate and o gm of thallium 

 sulphate in 100 co gave [«] = 5° 841 ; a solution containing 10 gm 

 of the tartrate and 5 gm of lithium sulphate gave [a\ = 10 o, 104, 



