certain Tartrate Solutions. 269 



while a mixture of equal volumes of the two solutions gave 

 [a] = 8° -089. 



Here, as in the case of the thallium sodium compound, addi- 

 tion of more thallium produces a great decrease in the specific 

 rotation, while addition of a lithium salt increases it. The re- 

 sult obtained from the mixture is greater than the mean of the 

 other two, and probably because the number of molecules of 

 lithium sulphate present is greater than the number of mole- 

 cules of thallium sulphate. 



Thallium Antimony Tartrate, Tl(SbO)C 4 H 4 6 . H 2 0. 



This salt was prepared by boiling thallium bitartrate with 

 pure precipitated antimonious oxide in a large excess of water. 

 On cooling, the salt separates out in small crystals which re- 

 semble the corresponding potassium compound. I found the 

 above formula by analysis. The salt is but slightly soluble in 

 water. For a solution containing 2 gm in 100 cc I obtained 



~a] 20 = 100°-443 

 "a] 88 = 99°'644 



It was shown above that a reduction of the specific rotation 

 by increase of temperature takes place in solutions of potassium 

 antimony tartrate. It would seem from these two experiments 

 that this change must be due to the presence of the antimony, 

 as in all other thallium solutions examined I find the tempera- 

 ture coefficient positive. The effect of addition of inactive 

 salts is shown in the following table, 2 gm of the thallium anti- 

 mony tartrate being used in each case except the last, where 

 4 gm were dissolved. 



Formula and amount of 

 inactive salt. 



NaSOi 2 gm. 



Na 2 S0 4 4 " 



NaO s H s O,.3H 2 2 " 



BLC2H3O2 2 " 



KN0 3 .__ 2 " 



K 2 S0 4 . 2 " 



NH 4 N0 3 2 " 



NH 4 N0 3 4 " 



NH 4 N0 3 (4gm. TISbOT) 2 " 



(NH 4 ) 2 S0 4 2 " 



(NH 4 ) 2 S0 4 4 " 



Especially noticeable in the above table is the fact that along 

 with a general reduction in the specific rotation, because of the 

 presence of inactive salts, there is a very marked reduction in 

 the two solutions containing acetates. These two solutions had 

 to be prepared without application of heat, as the slightest 

 elevation of temperature produced precipitation. It will be 

 remembered that an analogous reduction was noticed in the 



Observed 



Specific 



Deviation 



rotation. 



rotation. 



from 



a 



[a] 



normal. 



r-9i2 



99°-0G0 



— l°-383 



7 -875 



98 -596 



— 1 -847 



7 -092 



88 -799 



— 11 -644 



6 -928 



86 -748 



— 13 -695 



7 -858 



98 -385 



- 2 -058 



7 -850 



98 "295 



— 2 -148 



7 -854 



98 -341 



— 2 -102 



7 -715 



96 -590 



— 3 -853 



15 -663 



98 -059 



- 2 -384 



7 .830 



98 -040 



— 2 -403 



7 -747 



97 -002 



- 3 -441 



