he, without fuss, accepted the statements of the fugitive eye-witnesses,
down to the assertion that the cloud, as it rolled travelling, seemed
mixed from its base to the clouds with languid tongues of purple flame,
rose-coloured at their edges. This, Sloggett explained, was the
characteristic flame of both cyanogen and hydrocyanic acid vapour,
which, being inflammable, may have become locally ignited in the passage
over cities, and only burned in that limited and languid way on account
of the ponderous volumes of carbonic anhydride with which they must, of
course, be mixed: the dark empurpled colour was due to the presence of
large quantities of the scoriae of the trappean rocks: basalts,
green-stone, trachytes, and the various porphyries. This article was
most remarkable for its clear divination, because written so early--not
long, in fact, after the cessation of telegraphic communication with
Australia and China; and at a date so early Sloggett stated that the
character of the devastation not only proved an eruption--another, but
far greater Krakatoa--probably in some South Sea region, but indicated
that its most active product must be, not CO, but potassic ferrocyanide
(K_4FeCn_6), which, undergoing distillation with the products of sulphur
in the heat of eruption, produced hydrocyanic acid (HCn); and this
volatile acid, he said, remaining in a vaporous state in all climates
above a temperature of 26.5° C., might involve the entire earth, if the
eruption proved sufficiently powerful, travelling chiefly in a direction
contrary to the earth's west-to-east motion, the only regions which
would certainly be exempt being the colder regions of the Arctic
circles, where the vapour of the acid would assume the liquid state, and
fall as rain. He did not anticipate that vegetation would be permanently
affected, unless the eruption were of inconceivable duration and
activity, for though the poisonous quality of hydrocyanic acid consisted
in its sudden and complete arrest of oxidation, vegetation had two
sources of life--the soil as well as the air; with this exception, all