462 BEPORT — 1886. 



much less. The lower terms may, in fact, be regarded fairly as formed 

 on the same type as water : — 



C^}0, ^2^}0,&c. 



But when the hydrocarbon radicle becomes very large and complicated it 

 is much nearer the truth to say that the resulting substances are formed 

 on the type of hydrocai'bons, in which H is replaced by the water residue, 

 the latter forming so small a portion of the whole that it fails to impress 

 on the compound its own characteristics. We have, then, among the 

 alcohols — 



PTT TTO ) 



3 I resembling water and miscible with water 



p2 5 r iji all proportions. 



p^-TT^ TTj-j n [ not miscible in all propoi'tions. 



CifjHjjHO m.p. 50° I fusible, waxy solids, insoluble in water, but soluble 

 C27H55HO m.p. 97° ;- in ether and hydrocai'bons, resembling the hy- 

 C3,',H6iHO m.p. 85°j drocarbon CigHaj m.p. 21°. 



Again — 



Solubility in Water. 



Benzene . . CsH^H insoluble, though fusible. 



Phenol . . CuHjOH slightly soluble. 



Catechol . . ~| 



Quinol . J C|;Hj(0H)2 easily soluble. 



Resorcinol . J 



Pyrogallol . CsH3(0H)., still more soluble. 



And— 



Order of Solubility 

 in Water. 



Phenol . . CsH^OH . .1 "| All easily soluble in alcohol, 

 Naphthols . C,„H;OH . . 2 '■ ether, and especially ben- 



Anthrols . C,,HgOH . .8 J zene. 



Dr. Carnelleyhas taken up the question of the relation between atomic 

 constitution and solubility from a diflFerent point of view, and he has shown 

 by reference to many examples, drawn chiefly, though not exclusively, 

 from the aromatic division of carbon compounds, that of two isomeric 

 compounds the one which has the less symmetrical constitution has 

 the lower melting-point and the greater solubility ('Phil. Mag.' 

 February and March 1882). 



Kremers in 1854 and 1855 attempted a discussion of the relations 

 between the constitution of salts and their solubilitj (' Pogg. Ann.' xcii. 

 497, and xciv. 87 and 255). He seems to have arrived at no very definite 

 conclusions. One thing which he attempted to do was to trace the con- 

 nection between atomic (molecular) volume and solubility, and he would 

 probably have been more successful if he had had the advantage of a 

 uniform and consistent system of atomic weights. As it was, he arrived 

 at the conclusion (' Pogg.' xciv. p. 90) that ' greater atomic volume is 

 associated sometimes with greater solubility, sometimes with less.' This 

 part of the subject has been taken up more successfully by Dr. Nicol 

 (' Phil. Mag ' June 1884, January 1886), and he has shown that the 

 molecular volume of certain salts is larger in strong solutions than in 



