450 Speyers and Rosell — Resorcinol in Ethyl Alcohol. 



nearly saturated solution absorbs heat, and the heat of fusion 

 is +. 



Consequently the above statement does express the behavior 

 of resorcinol with ethyl alcohol so far as heat of solution and 

 solubility are concerned. 



Since heat is rejected when resorcinol dissolves in a large 

 excess of ethyl alcohol and since heat is absorbed when it dis- 

 solves in a small quantity, the temperature should not change 

 when these substances are mixed in some certain proportion. 

 This proportion was found to be about 6 grams of resorcinol 

 with about 100 grams of ethyl alcohol. 



The solubilities in all the following 37 cases increase with 

 the temperature and so the heat of solution of all the solids in 

 a nearly saturated solution should be +. This demands that 

 the heat of fusion should be larger than the heat of mixing the 

 liquid solute and solvent whenever the sign of this latter 

 heat is — . 



The signs refer to the heat of dilution of a saturated solu- 

 tion with about 5 per cent or 10 per cent of pure solvent. 



H 2 CH 3 OH C0H5OH C 3 H 7 OH CHCI3 C 7 H 8 



Urea + ± 



Urethane + + + + — 4- 



Chloral hydrate — — + + 



Succinimid + ± . 



Acetamid — + 



Mannitol ± 



Resoi*cinol + — 



Benzamid.. ± 



p-Toluidin + 



Acetanilid — ± + 



Acenaphthene _, ± ± ± — — 



Naphthalene . — ± — — — 



Phenanthrene ± — 



Cane sugar — 



Rutgers College, Sept. 1, 1900. 



