SOUFRIERE, AND ON A VISIT TO iMONTAGNE PELEE, IN 1902. 
517 
combine gradually and quietly, as the temperature fell, without occasioning any 
explosion whatever. Some, however, of the products of dissociation would escape 
combination, and these might, if not too much diluted with other ingredients, be 
ignited by lightning flashes at a later period, though we are not inclined to regard 
this process as having taken place on any but a very small scale. 
Others, of whom Professor Heilpein * is one, hold that , the cloud was highly 
charged with mephitic carbon gases. This theory is interesting, though we cannot 
endorse it:— 
“ tVhiit the exact con-stitutioii of this death-dealing cloud was will never perhaps be known, but its 
associations with the mud discharges, its heavy specific gravity, and the mephitic or oily odour of the 
products emitted by both the lower and upper craters, lend reasonable certainty to the I)elief that this 
glowing cloud was mainly composed of one of the heavier carbon gases brought under pressure to 
a condition of extreme incandescence, and whose liberation and contact with the oxygen of the 
atmosphere, assisted by electric discharges, wrought the explosion, or series of explosions, that developed 
the catastroi^he. 
“ To the enquiry as to what was the soiu’ce of this carbon gas—to my mind the main factor of the 
catastrophe—the geologist points to those vast bituminous deposits, like those of Venezuela and the 
island of Trinidad, which lie but little out of the line of the connected series of volcanoes, of which the 
Soufriere of St. Vincent, and Pelee of INIartinique, are a part. He also points to the limestone deposits, 
with their enormous masses of locked-up carbon, forming the foundation on which these same volcanoes 
are implanted, which indicate a source of energy far greater than was required for the catastrophe 
of Pelee.” 
When we were in St. Vincent we made most careful inquiries, both of the survivors 
and of the medical men who had attended the injured, as to the occurrence of 
poisoning by carbon dioxide, carbon monoxide, or poisonous hydrocarbons. We 
failed to find any evidence whatever of symptoms such as would have indicated that 
much of these gases was jn’esent, and the medical men were all convinced that they 
were not responsible for the fatal effects of the great black cloud. This seems to us 
all the more remarkable, as such gases must have been present in the cloud which, on 
May 7th, did such deadly havoc in the Carib Country, and this for a reason which has 
apparently escaped the American professor. 
That afternoon, as the darkness was closing in around the north end of St. Vincent, 
the richly-wooded slopes were still covered with all their wealth of tropical forest up 
to the moment of the climax, when the great dust avalanche arose. In an instant all 
was changed. The hot sand which now fills the valleys is mingled with innumerable 
fragments of charred, broken trees, caught up, destroyed, and swept along in that 
burning flood. The great hot blast which radiated outwards mowed down the 
standing trees, scorched them, eroded them, consumed their leaves, twigs, and 
smaller branches. The amount of vegetable matter carbonised or semi-carbonised 
in that brief space was enormous. The charcoal in the valleys is washed out and 
floats on the sea, supplying the inhabitants with fuel for months to come. Never 
* ‘ Fortnightly Review,’ September, 1902, pp. 477 and 478. 
