338 EXPERIMENTS ON THE METALS FROM THE FIXED ALKALIS, 



burnt with a beautiful red light *, and the whole mass ap- 

 peared in igneous fusion ; a little muriate of potash, in the 

 state of a white powder, sublimed and collected in the top 

 of the vessel in which the experiment was made. Nearly 14 

 cubical inches of muriatic acid gas were absorbed, and about 

 5 of hidrogen were produced. The increase of weight of the 

 tray was about 4*5 grains ; and it did not lose any weight by 

 being ignited. 



Exp. 2. The second experiment was conducted with still more at- 



tention to minuteness. 8 grains of potassium were employed; 

 above 22 cubical inches of muriatic acid gas were consumed; 

 the potassium burnt with the same brilliant phenomena as in 

 the last experiment, and the increase of weight of the tray 

 was 6| grains. The muriate of potash was kept for some 

 minutes in fusion in the tray, till a white fume began to rise 

 from it, but it did' not lose the —^ of a grain in weight. 

 After the muriate of potash had been washed out of the tray, 

 and it had been cleaned and dried, it was found to have lost 

 about a third of a grain, which was platinain a metallic state, 

 and that had alloyed with the potassium, where it was in 

 contact with the tray, during the combustion. There was no 

 appearance of any water being separated in the process. A 

 little muriate of potash sublimed ; this was washed out of 

 the retort, and obtained by evaporation : it did not equal £ 

 of a grain. 



Deductions. Now if the data for calculation be taken from this last ex- 



periment, 8 grains of potassium will combine with 1*4 

 grains of oxigen, to form 9*4 grains of potash, and 6'6 — 

 1-4 = 5*2, the quantity of muriatic acid combined with the 

 potash ; which would give in the 100 parts in muriate of 

 potash, 35*6 of acid, and 64*4 of potash. But 35*6 of 

 muriatic acid, according to Mr. Berthollet's estimation, 

 would demand 71*1 of alkali, in the state of dryness in 

 which it exists in muriate of potash; and 71*1 — 64*4 = 

 6'7 ; so that the potash taken as a standard by Mr. Ber- 

 thollet contains at least 9 per cent more water, than 



* As a retort exhausted of common air was used, the small quan- 

 tity of residual common air may have- been connected with this vivid- 

 ness of combustion. 



1 that 



