1813.] . On the Nature of Muriatic Acid. 255 



is called euchlorine. Chlorine combines likewise with an atom 

 of hydrogen. The compound formed is muriatic acid. This 

 acid is analogous to sulphureted hydrogen and tellureted hy- 

 drogen, and, like these two acids, it is decomposed- by the 

 greatest number of the saline bases, the oxygen of which com- 

 bines with the hydrogen of the acid, and forms water, at tho 

 same time that the metallic radicle of the base unites with the 

 chlorine. Muriatic acid parts with its hydrogen still more easily 

 than the two above-mentioned acids, since it is decomposed by 

 oxides which neither alter sulphureted nor tellureted hydrogen ; 

 by potash and soda, for example. On the other hand muriatic 

 acid is neither decomposed by atmospheric air, nor oxygen gas, 

 as happens to the compounds of hydrogen with sulphur and 

 tellurium. What we have hitherto called muriate of potash and 

 muriate of soda, is nothing but a compound of chlorine and the 

 metallic radicles of these oxides. The only bases, which do not 

 decompose muriatic acid, are ammonia, alumina, and in some 

 measure also magnesia. The salts called hyperoxyynuriatts are 

 combinations of euchlorine with the peroxides of the bases. 

 Chlorine combines with all combustible bodies except carbon, 

 and perhaps also boron, but it combines with the oxide of carbon. 



Such is an outline of each hypothesis. I shall in the first place 

 examine the circumstances by which the illustrious author of the 

 new hypothesis considered himself as obliged to abandon the 

 old opinion. I shall afterwards state some facts which agree 

 very well with the old hypothesis, but not with the new. 



It has not escaped the sagacity of Davy that chlorine may 

 contain oxygen ; but having exposed salifiable bases to the action 

 of oxymuriatic gas, he found that the quantity of oxygen evolved 

 was exactly equal to that contained in the oxide employed. 

 Hence he concluded that this oxygen could not be furnished by 

 the oxymuriatic acid gas, but was derived from the oxide; the 

 radicle of which, having a stronger affinity for chlorine than for 

 oxygen, parted with its oxygen and united with the chlorine. 

 Before the establishment of the doctrine of definite proportions 

 in chemistry, the experiments just stated might certainly war- 

 rant a new conjecture respecting the nature of oxymuriatic gas; 

 but at present it is established by that doctrine, that the oxymu- 

 riatic acid is composed of one atom of radicle and three atoms 

 ol oxygen ; that it is capable of neutralizing a quantity of any 

 whatever, the oxygen in which amount* to half the oxygen 

 in the acid; and that, of consequence, the quantity of oxygen 

 igaged from the oxymuriaticgas decomposed by a saline base 

 ii eomal to that contained in the base by which ii ia decomposed, 



I lydrogen gas unites with oxymuriatic gas, anil tonus a mu- 

 >>\ water, without any excess either of water or muriatic 



i' id. Thi- experiment, being conformable to the old hypothesis, 



