1817.) during the Year 1816. 23 
ments it follows that, after decomposition, the bulk of the chlorine 
was to that of the oxygen as two to three. From this it follows that 
deuto-chlorous oxide is composed of one atom chlorine and three 
atoms oxygen. Hence it is probably a different substance from the 
gas examined by Davy. When deuto-chlorous gas and hydrogen 
are mixed, no change takes place at the common temperature of 
the atmosphere; but when an electric spark is passed through the 
mixture, a detonation takes place, and the whole is converted into 
muriatie acid and water. According to Count von Stadion’s experi- 
ments, three measures of deuto-chlorous gas require eight measures 
of hydrogen. This is the proportion that ought to follow from the 
composition of deuto-chlorous gas as determined by Stadion’s expe- 
riments. . 
Water absorbs at least seven times its volume of deuto-chlorous 
oxide. The solution has a deep yellow colour, a peculiar pungent 
taste, and the distinguishing odour of deuto-chlorous oxide. It may 
be kept in the dark in close vessels without undergoing any change, 
but when exposed to the solar rays the oxide is decomposed, and 
converted into chlorine, and the chloric acid of Gay-Lussac. The 
colour disappears, and the liquid assumes the smell of chlorime. 
When heat is applied, the chlorine is driven off, and pure chloric 
acid remains behind. The evaporation must be conducted at a 
temperature between 112° and 144°, and be continued till about 
one-fourth of the liquid is driven off. The residue has then lost the 
odour of chlorine, and does not precipitate nitrate of silver. The 
deuto-chlorous gas is decomposed in the same way, but more 
slowly, when left in contact with alkaline bases, or with metals. 
When deuto-chlorous oxide is procured by this process, there is a 
peculiar salt formed, which has been hitherto overlooked. This 
salt is best obtained by adding three or four grains of strong sul- 
phuric acid for every grain of chlorate of potash employed. After the 
first violent action of the acid is at an end, heat is to be applied, 
and continued till the yellow colour of the mass disappears. ‘The 
salt formed in this way is mixed with bisulphate of potash, which 
may be separated by a second crystallization. ‘This salt possesses 
the following properties :— 
It is quite neutral, is not altered by exposure to the air, and has a 
weak taste, similar to that of muriate, of potash. It dissolves in 
considerable quantity in boiling water ; but water at the tempera- 
ture of 60° dissolves only -1,th part of its weight. In alcohol it is 
quite insoluble. Its crystals appear to be octahedrons, and to belong 
to the variety distinguished by Haiiy under the name plomb sulfaté 
semi-prismé, and figured by him in his 69th plate, fig. 73. It de- 
tonates fecbly when triturated ina mortar with sulphur, When 
heated to 412°, it is decomposed, and converted into chloride of 
potassium (muriate of potash) and oxygen gas. When this salt is 
mixed with its own weight of sulphuric acid, and exposed to a heat 
of 280° ina retort, it is decomposed, and the acid which it contains 
