540 



Mr. C. G. Williams. 



[Mar. 17, 



tinum solution, a dense bright yellow precipitate was formed ; to the 

 filtrate more platinum solution was added, and so on until four pre- 

 cipitates were obtained. The second, third, and fourth were buff 

 coloured, but the last on standing became of a dirty brown colour. 

 The two last were in too small quantity for analysis. 



The first precipitate gave 18*47 per cent, of platinum. Assuming 

 for the present that the yellow solid base from the recovered chinoline 

 is isomeric with that which yields the scarlet hydrochlorate, it may be 

 mentioned that a salt having the formula — 



2 (C 18 H 14 N2)4HCl.PtCl 4 



would require 19*76 per cent, of platinum. The second precipitate 

 gave 23 "49 per cent, of platinum, and yielded, therefore, almost the 

 same percentage of the metal as the second precipitate obtained 

 from the product of the action of sodium upon the original 

 chinoline, and the remarks made upon that precipitate apply equally 

 to the present one. 



Experiments were subsequently made to ascertain if, in presence 

 of excess of hydrochloric acid, platinum salts of a different constitu- 

 tion would be formed. For this purpose 1 grm. of the new solid 

 base was treated with 10 cub. centims. of strong hydrochloric acid, 

 it dissolved with effervescence as if carbonic anhydride had been 

 absorbed; the solution took place with moderate readiness; it was 

 filtered and treated with solution of platinum as before, a buff 

 coloured precipitate was obtained ; at this point 10 cub. centims. 

 more hydrochloric acid were added, the precipitate became smaller, 

 25 cub. centims. more hydrochloric acid were added at this stage, 

 and the solution was heated to about 90° and filtered ; much of the 

 platinum salt remained on the filter, and, after drying, gave 23*92 

 per cent, of platinum, the mother-liquid on cooling gave another 

 precipitate containing 24*55 per cent, of platinum; both these pre- 

 cipitates appear, therefore, in spite of the great excess of acid in 

 which they were formed, to be constituted like the second precipi- 

 tates previously obtained. 



The solid yellow base contained 3 06 per cent, of ash, which con- 

 sists of carbonate of lime with a trace of iron, both derived from the 

 chemicals used in its preparation. 



The solid base when heated fuses to a yellow oil, giving off pre- 

 cisely the same odour as chinoline compounds generally ; near a red 

 heat it boils away leaving some carbon which, contrary to the usual 

 rule in such cases, burns away readily. 



Nitric acid dissolves the base easily, giving a reddish brown solu- 

 tion which on dilution with water affords a yellow precipitate; 

 ammonia turns the solution red, and partially dissolves the pre- 

 cipitate. 



