21G 



Frederick Guthrie on Salt Solutiotin 



The cryohvdrate of acetate of potassium has not yet been 

 determined. 



The temperature of the cryogen of acetate of potassium is 

 -25° a 



It is well known that fused acetate of potassium is heavier 

 than the anhydrous solid acetate at the same temperature ; but 

 I do not find the remarkable fact anywhere noticed, that the 

 fused anhydrous salt is also lighter than the aqueous solution 

 of the salt saturated at ordinary temperatures (17° C). 



(2) A few Organic Crystalloids in Aqueous Solution; their 

 behaviour on being cooled and on being heated T and as 

 Cryogens, 



§ 158. Cane-sugar. — Sugar-candy was finely powdered and 

 dried at 100° C. in a current of dry air. 



Table XXXYII. 



C 12 H 22 llP er 



cent, by weight. 



H 2 O per cent. 

 by weight. 



Temperature 

 at which solidi- 

 fication begins. 



Nature of solid 

 formed. 



5 



95 



o 



-03 



Ice. 



10 



90 



—0-5 



„ 



15 



85 



-0-9 



„ 



20 



80 



-13 



t1 



25 



75 



-1-8 



yt 



30 



70 



-2-4 



„ 



35 



65 



-3-2 



»> 



40 



60 



-4-1 



h 



45 



55 



-5-4 





50 



50 



-70 



, 



51-4 



48-6 



-8-5 



Cryohydrate. 



(Mean) 6733 



3267 



©•0 



C 12 H 22. 11- 



Solutions stronger than the cryohydrate may be cooled 

 below — 8°*5 before solidification begins. A 60-per-cent. so- 

 lution does not show signs of solidification above — 11 0, 4. 

 The solid which separates, however, is sugar. This is a con- 

 sequence of the supersaturability of sugar solutions, and the 

 possibility of the condition of supersaturation being maintained 

 even in solutions from which crystals of sugar are being depo- 

 sited. Also, as was so notably the case with alcohol, the cryo- 

 hydrate is an abundant solvent for sugar. The cryohydrate of 

 saccharose was analyzed by evaporation. 



2*2658 grms. gave 1*5244 grm. of saccharose, or 51'4. 

 For the solubility at 0° a solution saturated at + 20° was 

 kept for three days and nights at 0° C. 



3*6300) 2*4510 , , 



4-1175 i g ave 9-7640 saccharose or cane-sugar. 



