102 Experiments on the Relation letween 
regarded as of scarcely inferior importance. If established, it 
leads to the adoption of entirely new views concerning combus- 
tion and many of its products; it removes the muriates, a set of 
apparently well characterized saline bodies, from the class of salts 
altogether ; and it has given birth, by analogy, to two new ge- 
nera of compounds, in which iodine and fluorine, like chlorine, 
act a corresponding part with oxygen, in the system of La- 
voisier. 
This new era in chemical science unquestionably originated 
from the masterly researches of Sir Humphry Davy on oxy- 
muriatic acid gas; a substance which, after resisting the most 
powerful means of decomposition which his sagacity could in- 
vent, or his ingenuity apply, he declared to be, according to the 
true logic of chemistry, an elementary body, and not a com- 
pound of muriatic acid and oxygen, as was previously imagined, 
and as its name seemed to denote. He accordingly assigned to 
it the term Chlorine, descriptive of its colour ; a name now ge- 
nerally used. 
Chlorine when combined with an equal volume of hydrogen 
forms muriatic acid gas, the hydrochloric of Gay-Lussac. This 
muriatic acid gas, hygrometrically dry, unites with its own bulk 
of dry ammoniacal gas, to constitute the dry pulverulent solid 
called sal ammoniae. Hence this saline body is ultimately com- 
posed of chlorine and hydrogen, for its acid; and of azote and 
hydrogen for its base. By comparing the weights of muriatic 
acid and ammoniacal gases, in equal volumes, we obtain the 
proportion of 67:8 muriatic acid gas to 32°2 ammonia, for the 
composition of 1()0 parts by weight of the solid salt. If we sa- 
turate liquid muriatic acid with gaseous ammonia, or with the 
base of the ammoniacal carbonate, and evaporate carefully to 
dryness, we find the resulting salt to have precisely the same 
constitution, namely, in 100 parts, 5] of dry muriatic acid, equi- 
valent to 67°S of the acid gas, and the remainder 32:2 ammonia. 
This concurrence of results, whatever way the salt may be ob- 
tained, is fully demonstrated in my researches on the ammonia- 
eal salts, (Annals of Philosophy for September 1817,) and proves 
it to be a substance of very uniform and determinate composi- 
tion. 
Those chemists who consider chlorine to be oxvmuriatic acid 
must suppose, when a volume of it weighing 44°13 unites with 
an equal volume of hydrogen weighing 1°32, that, in the re- 
sulting hydrochloric or muriatic acid gas =45:45, this hydrogen 
exists combined with 10°00 of oxygen, its saturating quantity, 
forming |1-32 of constituent water. In this view, muriatic acid 
gas, like gaseous, sulphuric, and nitric acids, contains water as 
an essential element. There seems to be no violation of chemi- 
cal 
