Oxymuriatic acid

When Davy allowed oxymuriatic acid gas (chlorine) to react with moist sulfur, he obtained hydrogen chloride and oxygen. When he repeated the experiment, using Sicilian sulfur dried over calcium chloride, no oxygen gas was evolved and not a cubical inch of muriatic [hydrochloric] acid. . . and it was found that between 16 and 17 cubical inches of oxymuriatic acid gas [chlorine] had disappeared the whole of the sulfur was sublimed in the gas, and the liquor formed was of a tawny-orange colour [probably sulfur monochloride] (30). 

In 1814 Thomas Charles Hope of Edinburgh wrote in a letter to the British Quaker chemist William Allen I should be very glad to know what doctrine you teach now with regard to oxymuriatic acid. Are you yet a convert to chlorine I am impatient to see Lussac s paper on iodine, in particular to learn how far the facts respecting that substance go to confirm the new views of chlorine. Lussac appears to be a convert to Davy s sentiments, and certainly the acquisition of one who so strenuously opposed them must be accounted a very flattering occurrence (117). 

He then cites the sulfurous and sulfuric acids, as differing in the amount of oxygen they contain, with no combination lying between them the muriatic acid and the oxymuriatic acid [chlorine] similarly exhibit different degrees of saturation with oxygen. But... 

I introduced phosphorus into a receiver having a stopcock, which had been exhausted, and admitted oxymuriatic acid gas. As soon as the retort was full the phosphorus entered into combustion, throwing forth pale white flames. A white sublimate collected in the top of the retort, and a fluid as limpid as water trickled down the sides of the neck. The gas seemed to be entirely absorbed, for, when the stopcock was opened, a fresh quantity of oxymuriatic acid gas, nearly as much as could have filled the retort, entered. The same phenomenon of inflammation again took place, with similar results. Oxymuriatic acid gas was admitted until the whole of the phosphorus was consumed. 

For a long time chlorine was considered to be compound in nature. Berzelius, too, believed this and disagreed with Davy, who considered it an element. Davy s illuminating experiments later convinced the Swede that chlorine was not oxymuriatic acid, an oxygen compound of hydrochloric acid, but a simple elementary gas. When Anna, his housekeeper, complained that a dish she was cleaning smelled of oxymuriatic add, Berzelius now corrected her Listen, Anna, you must not say oxidized muriatic acid any more. Say chlorine, it is better. ... 

In 1800, W. Henryk passed electric sparks through muriatic acid gas and obtained a little hydrogen which he supposed to come from the moisture in the gas ou sparking a mixture of oxygen and muriatic acid gas he obtained a little oxymuriatic acid gas which he supposed was formed by the electric sparks decomposing some of the moisture in the muriatic acid gas into oxygen, and the union of the oxygen with the muriatic acid gas to form oxymuriatic acid gas. The experiments... 

In an experiment of fundamental importance, after having exposed a mixture of one volume of carbonic oxide and one volume of oxymuriatic acid to bright sunshine. Dr. Davy noticed that the color of the chlorine has entirely disappeared, and that the remaining gas occupied the space of one volume. After addition of ammonia, he found no traces of carbonic oxide and observed an effervescence of the ammoniacal salt formed with nitric acid. He also noticed that the new gas resulting from the evident action of oxymuriatic acid and carbonic oxide did not fume when thrown into atmosphere and that it had a most intolerable suffocating odor and that water absorbed it very slowly. 

These results were however again contested by Dr. Murray who, to support his opinion that oxymuriatic acid and carbon monoxide do not react, quoted unsuccessful trials from French chemists Gay-Lussac and Thenard ... 

In the early beginning of the 19th century, chlorine gas was still uniformly considered as a combination of muriatic acid (hydrochloric acid) and oxygen called oxymuriatic acid . 

However, in 1810, Dr. John Davy, Sir Humphry Davy s younger brother, expressed the opinion that oxymuriatic acid was, as a matter of fact, an elementary substance. This opinion was not at all accepted and several scientists, in order to refute the arguments of Dr. Davy, tried therefore to remove oxygen content of oxymuriatic acid by treatment with charcoal at a white heat or with carbon monoxide [Scheme 1],... 

Scheme 1 Expected de- oxygenation of oxymuriatic acid (chlorine).

Muriatic acid and marine acid were synonymous terms for what is now called hydrochloric acid, thus signifying its relation to the sodium chloride contained in brine (Latin muria) or sea water (Latin mare). Both names were strongly criticized by H. Davy in a scathing paper entitled Some reflections on the nomenclature of oxymuriatic compounds in Phil. Trans. R. Soc. for 1811 To call a body which is not known to contain oxygen, and which cannot contain muriatic acid, oxymuriatic acid, is contrary to the principles of that nomenclature in which it is adopted and an alteration of it seems necessary to assist the progress of the discussion, and to diffuse just ideas on the subject. If the great discoverer of this substance (i.e. Scheele) had signified it by any simple name it would have been proper to have referred to it but... 

For many years chlorine was regarded as a compound of oxygenf. Its method of preparation appeared to suggest this, the gas being obtained by the oxidation or muriatic acid. Lavoisier therefore called it oxymuriatic acid under such a name it fitted into Lavoisier s... 

Davy had independently done many experiments attempting to extract oxygen from oxymuriatic acid, and in the report of Gay-Lussac... 

Chenevix" regarded muriatic acid as an element oxymuriatic acid and the gas obtained by the action of sulphuric acid on potassium chlorate (chlorine dioxide, regarded by Chenevix as a mixture of chloric acid and chlorine), were oxides of this element. W. Henry by sparking muriatic acid gas over mercury obtained hydrogen, and the mercury was attacked by what he believed to be oxygen, hence he assumed that muriatic acid gas contains combined water. 

Oxygenated muriatic gas is not decomposed by carbon, and it can be supposed from this fact and those reported in this memoir, that this gas is a simple body. The phenomena which it presents are equally well explained by this hypothesis we do not, however, seek to defend it, since it seems to us that they are still better explained by regarding oxymuriatic acid as a compound body. ... 

---