192 PROCEEDINGS OP THE AMERICAN ACADEMY 



Potassic 8-Su!phopyromucate, K 2 C 5 H 2 SO . 4 H 2 0. The potassium 

 salt is extremely soluble even in cold water, and crystallizes in long 

 slender prisms, which apparently contain four molecules of water. 

 They effloresce quite rapidly when exposed to the air, and our deter- 

 minations of the water of crystallization are, therefore, not entirely 

 satisfactory. 



I. 2.4108 grm. of the salt dried by short exposure to the air lost, at 

 135", 0.4966 grm. H 2 0. 

 II. 0.9701 grm. of the salt dried by pressure only lost, at 100°, 0.2074 



grm. HoO. 

 III. 1.3420 grm. of the salt dried by short exposure to the air lost, at 

 115°, 0.2775 grm. H 2 0. 



H,0 



r 



I. 0.5573 grm. of the anhydrous salt gave 0.3608 grm. K 2 SO 

 II. 0.5035 grm. of the anhydrous salt gave 0.3242 grm. K„S0 4 . 



Calculated for Found. 



K 2 C 5 H„S0 6 . I. II- 



K 29.16 29.07 28.91 



Acid Potassic 8-Sulphopyromiicate, KC 5 H 3 SO c . — The acid potas- 

 sium salt is very soluble in water, and crystallizes in large anhydrous 

 prisms. 



I. 0.8655 grm. of the salt gave 0.3253 grm. K 2 S0 4 . 



II. 0.8290 grm. of the salt gave 0.3127 grm. K 2 S0 4 . 



III. 0.7694 grm. of the salt gave 0.2879 grm. K 2 S0 4 . 



K 



Sodic 8-Sulphopyromucate, Na 2 C 5 H 2 SO . 5 H 2 0. — The neutral 

 sodium salt is extremely soluble in water, and crystallizes in long 

 slender needles, which appear to contain five molecules of water. 

 The same salt is obtained in the form of fine felted needles by crys- 

 tallization from dilute alcohol. 



