514 
DTJs. T. ANDEUSOX AXD J. S. FLETT OX THE EHUPTIOXS OF THE 
The theory of explosions has also won a certain number of adherents, among 
whom are several distinguished American geologists. That there was an explosion 
— a steam explosion—is, of course, admitted by all. But some hold that there 
were also explosions of combustible gases attended by sheets of flame, and that 
these took place either during or shortly after the outburst from the crater. 
Our ol)jection to these theories is that they have no sufficient basis of observed facts 
on which to stand. Neither wliat we know about the gases in the cloud, nor the 
recorded observations of eye-witnesses of the eruptions, make it in any way probable 
that such explosions took place except on a minor scale, or that they had an essential 
jmrt in the projjulsion of the discharges. 
Many, of cour-se, who saw tlie great ITack cloud emerge from Pelee or the Soufriere 
descril)e it as welliuGf out of the hill vuth sheets of flame. But students of volcanic 
})henomena are too well acquainted with such descriptions to place any great reliance 
upon them. The popular mind is not careful to distinguish between a mere 
incandescent discharge, or the glow of the red-hot surface of the lava reflected fi’om 
overhanffino- clouds, and true sheets of flame. The belief in burnino; mountains dies 
hard. 
On two separate occasions we have witnessed the black cloud which rises from the 
fissure of Pelee, and on neither did we see any flame. Through the face of the cloud 
lights flickered and scintillated, but they vmre onl}^ lightnings. We have cross- 
examined many careful and accurate olrservers who have seen more than one eruption 
of the Soufriere, and not one of them described them as attended by flames. Neither 
were the noises they heard like the detonations of aerial explosions, thev came from 
within the mountain. It is no doubt possilfle to obtain declarations from eve- 
witnesses, stouting that great flames were visible, hut they either tweak down 
altogether on careful cross-questioning, or are advanced by persons too uneducated, 
too excited, and often too inaccin'ate, to give evidence of any value in matters of this 
sort. 
The Gases of the Cloud .—This raises the question—What were the gases in the 
cloud, and what v^ere their properties ? Unfortunately, this is a subject at present 
imperfectly knovm. We can only approacli the (piestion by indirect methods ; no 
one lias bottled a sample of the great black cloud. But ivhat evidence is available is 
singularly consistent, and makes it higlily improbable that great explosions due to 
chemical comliinations between the gases of the cloud, or between these gases and 
those of the atmosphere, played any conspicuous jiart in the mechanism of the 
eruptions. 
The gases of the cloud were the gases of the andesitic magma. The great black 
mass cleaved the air, driving it aside in virtue of its weight and the expansive 
forces within it. The atmosphere was passive, inert ; it could not penetrate to the 
Interior of the rushing inky torrent; only at the margins, where the cloud sent out 
curling wreaths of dusty vapour, was there any mingling between it and the air. 
