338 Prof. H. Rose on the Isomeric Modifications 



Solution o^ protosulphate of iron produces a white precipi- 

 tate, which is readily soluble in excess of the solution of the 

 protosalt. A copious precipitate is thrown down by heat, 

 and does not completely disappear on cooling. 



In a solution of the perchloride of iron a white precipitate 

 is formed, which is readily soluble in excess of the solution of 

 the perchloride. 



Solution of the sulphate of zinc produces a white precipi- 

 tate, which is readily soluble in excess of the solution of zinc. 

 When the solution is heated, a troubling ensues; it is but 

 inconsiderable, and does not completely disappear on cooling. 



Solution of sulphate of cadmium causes a white precipitate, 

 readily soluble in excess of the solution of cadmium. The 

 solution yields a copious precipitate when heated, but this 

 completely disappears on cooling. 



Solution of chloride of nickel yields a greenish-white pre- 

 cipitate, soluble in excess of the solution of nickel. The solu- 

 tion, which yields a precipitate when boiled, becomes per- 

 fectly clear on cooling. 



Solution o( the sidphate of cobalt produces a blue precipi- 

 tate, soluble in excess of the solution of cobalt. The solution 

 is red. On ebullition, a red precipitate is produced in it, 

 which completely dissolves on cooling. 



Solution of alum gives a white precipitate, soluble in a con- 

 siderable excess of the solution of alum. When heated, the 

 solution yields a copious precipitate, which partly, but not 

 entirely, disappears on cooling. 



Solution of nitrate of bismuth gives a white precipitate, in- 

 soluble in excess of the solution of bismuth. 



Phosphate of soda does not cause a precipitate in a dilute 

 filtered solution of albumen ^ even when acetic acid is added. 



The aqueous solution of the c-phosphoric acid differs from 

 pyrophosphoric and metaphosphoric acids, as is well known, 

 by its reaction with a solution of silver. 



Solution of chloride of barium produces only an inconsider- 

 able turbidness; but on the addition of ammonia a copious 

 precipitate is immediately formed. 



Barytic water causes a precipitate, even when the liquid is 

 acid. The phosphoric acid is not completely separated by 

 carbonate of baryta in the cold. The liquid, filtered at the 

 end of several days, still yields a precipitate on the addition 

 of sulphuric acid. 



Solution of chloride of calcium gives no precipitate, even 

 after standing for a considerable time ; but ammonia imme- 

 diately causes a copious precipitate. Lime-water produces a 

 precipitate, even when the liquid is somewhat acid. 



