ee ee Se eee 
= 
ee 
~ 
Experiments on Muriatic Acid Gas. 195 
1746, in which Lima and Callao were destroyed, no: less than 
four new ones burst forth in the adjacent mountains*. 
36. To the same purpose, we may allege the instances of many 
volcanos lying together in the same tract of country: as for ex- 
ample, the many places, “not so few as forty,” ‘amongst the 
Azores, whieh either do now or have formerly sent forth smoke 
and flames; the many volcanos also amongst the Andes, already 
inentioned: thus fitna, Strombolo, and Vesuvius: I may add 
Solfatara too, are all in the same neighbourhood: and Mons. Con- 
damine says, he has traced lavas+, exactly like those of Vesuvius, 
all the way from.Florence to Naples. In Iceland t also, we have, 
besides Hzecla, not only several other voleanos, but also a great 
number of places, that send up sulphureous vapours. But the 
examples of this kind are so frequent, that there are few instances 
to be produced of single volcanos, without evident marks, either 
that there have been others formerly in their neighbourhood, or 
that there are, at present, subterraneous fires near them. 
[To be continued. | 
XXIX. Experiments on Muriatic Acid Gas, with Observations 
on its Chemical Constitution, and on some other Subjects of 
Chemical Theory. By Joun Murray, M.D. F.&.S. E. 
Fellow of the Royal College of Physicians of Edinburgh. 
[Continued from p. 112.] 
Awortner form of experiment occurred to me still more direct and 
simple, that of transmitting muriatic acid in its gaseous forin ever 
ignited metals. If water be obtained in this experiment, it is a 
result which would prove subversive ef the new doctrine; for 
muriatic acid gas is held to be the real acid, free from water, 
and the only change which can happen, is that of the metal de- 
composing the acid attracting its chlorine and liberating its hy- 
drogen. And the experiment is further free from the only re- 
source which remained to the advocates of that doctrine, in the 
ease of water being obtained from muriate of ammonia, that it 
might be derived from the decomposition of the elements of am- 
monia, regarding it as an alkali containing oxygen. If water 
were really obtained from the combination of miuriatic acid and 
ainmoniacal gases, it would rather indicate, it was said, the de- 
* See d'Ulloa’s Voyage to Peru, part ii. book i. chap. 7. 
+ See Phil. Trans. vol. xlix. p.624. | All these lavas, as well as the vol- 
anos just mentioned, lie in a continued line. The same thing holds good 
in the volcanos of the Andes also. This is a fact I must desire the reader 
to attend to, as it serves to confirm a very material doctrine, which [shall 
have occasion to mention hereafter. See art. 44, 45, and 46. 
1 See Horrebow’s Natural History of Iceland. 
N2 composition 
