DISCUSSION OF THE RESULTS. 141 



The results are given in tables 74 to 80. The freezing-point lowerings are 

 plotted in figs. 3, 4, 5, and 6, the conductivities in figs. 7, 8, 9, and 10, the 

 refractivities in fig. 13, and the hydrates in figs. 52 and 56. 



The strong mineral acids all show some hydrating power, but, with the 

 exception of chromic acid, this is limited to the more concentrated solutions. 

 Hydrochloric, hydrobromic, nitric, sulphuric, and phosphoric acids show 

 no hydrates in the more dilute solutions that were studied. Further, the 

 complexity of the hydrate passes through a maximum for a number of the 

 acids, at a concentration ranging from normal to about three times normal. 



These results are so fundamentally different from those that were obtained 

 with salts, and even with bases, that it raises the question as to what they 

 mean. Why this difference between acids and other electrolytes? 



A possible explanation of this phenomenon, which is in keeping with 

 the law of mass action, is the following: If the attraction of the dissolved 

 molecule for water is slight, then, when a certain dilution is reached, the 

 effect of the presence of more water might actually diminish the amount 

 of water combined with a molecule of the dissolved substance. When the 

 number of molecules of water had become sufficiently great, their attractions 

 for one another would summate, and might overcome, in part, the attraction 

 of the dissolved substance for the water, hi this case the complexity of the 

 hydrate would pass through a maximum and then decrease with further dilution. 



A number of neutral organic compounds have also been investigated, to see 

 whether these substances have any power to combine with water. The com- 

 pounds studied are: Methyl alcohol, ethyl alcohol, n-propyl alcohol, acetone, 

 acetamide, urea, chloral hydrate, glycerol, glucose, fructose, mannite, lactose, and 

 cane-sugar. 



The results are given in tables 81 to 93. The freezing-point data are 

 plotted in curves, figs. 58, 59, and 60, and the hydrates formed by fructose, 

 cane-sugar, and glycerol in fig. 61. 



Of the thirteen non-electrolytes studied in this investigation only glycerol 

 showed any marked hydration or power to combine with the solvent. Gly- 

 cerol combines with water to about the same extent as the ternary, or even 

 some of the quaternary electrolytes. 



Cane-sugar and fructose also show considerable power to combine with 

 water, but this is not even of the same order of magnitude as that shown 

 by glycerol. 



Methyl and ethyl alcohols also show some slight power to combine with 

 water in solution. 



A number of the non-electrolytes studied show a marked tendency to 

 undergo polymerization in the presence of water. 



Glycerol has much the greatest hydrating power of any non-electrolyte 

 investigated, and cane-sugar also shows this power to an appreciable extent. 



