and many tropical flora; also that it had been actually pointed out as probable by more than one thinker that some salt or salts of Cn, the potassic, or the potassic ferrocyanide, or both, must exist in considerable stores in the earth at volcanic depths.  In reply to this, Stanistreet in a two-column article used the word ‘dreamer,’ and Rogers, when Berlin had been already silenced, finally replied with his amazing ‘block-head.’  But, in my opinion, by far the most learned and lucid of the scientific dicta was from the rather unexpected source of Sloggett, of the Dublin Science and Art Department:  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 deg.  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 life, down to the lowest evolutionary forms, would disappear (here was the one point in which he was somewhat at fault), until the earth reproduced them.  For the rest, he fixed the rate of the on-coming cloud at from 100 to 105 miles a day; and the date of eruption, either the 14th, 15th, or 16th of April—­which