356 



PROCEEDINGS OF THE AMERICAN ACADEMY 



Senhofer ; but, whereas he states that only one and a half molecules 

 of the water are given off at 100°, we found that the whole was evolved 

 at this temperature. 



0.3768 grra. of air-dried salt at 100° lost 0.0431 grm. 



Calculated for CJIalSOaKJa 3 n20. 



Water 11.11 



Found. 



11.43 



0.7404 grm. of dry salt gave 0.442 grm. of potassic sulphate. 



Potassium 



Calculated foi* CcU3(S03K)3. 



27.13 



Found. 



26.80 



"We have determined the solubility of the potassium salt as fol- 

 lows : — 



I. 3.6594 grm. of a solution of C(;H3(S0,K)., saturated at 20° left on 

 evaporation 1.3074 grm. of the salt dried at 260°. 

 II. 2.034 grm. of the solution gave 0.716 grm. of the dried salt. 



Therefore a saturated solution of potassic benzoltrisulphonate at 

 20° contains the following percentages of the salt free from water of 

 crystallization. 



I. II. 



35.72 35.21 



Dr. O. W. Huntington has at our request determined the crystalline 

 form of the potassium salt CeH,(S03K)3 3 H^O, and kindly furnishes 

 us with the following statement : — 



Fig. 1. 



Fig. 2. 



" Monoclinic, with marked variation of type. As no planes were 

 observed except the basal plane and vertical domes, and pinacoids, it 

 was impossible to make a complete determination of the crystal. The 

 following measurements were obtained : — 



