“What was the last news when you left London?” he asked.

“I was at the Gazette office about ten,” said I.  “There was a Reuter just come in from Singapore to the effect that the sickness seemed to be universal in Sumatra and that the lighthouses had not been lit in consequence.”

“Events have been moving somewhat rapidly since then,” said Challenger, picking up his pile of telegrams.  “I am in close touch both with the authorities and with the press, so that news is converging upon me from all parts.  There is, in fact, a general and very insistent demand that I should come to London; but I see no good end to be served.  From the accounts the poisonous effect begins with mental excitement; the rioting in Paris this morning is said to have been very violent, and the Welsh colliers are in a state of uproar.  So far as the evidence to hand can be trusted, this stimulative stage, which varies much in races and in individuals, is succeeded by a certain exaltation and mental lucidity—­I seem to discern some signs of it in our young friend here—­which, after an appreciable interval, turns to coma, deepening rapidly into death.  I fancy, so far as my toxicology carries me, that there are some vegetable nerve poisons——­”

“Datura,” suggested Summerlee.

“Excellent!” cried Challenger.  “It would make for scientific precision if we named our toxic agent.  Let it be daturon.  To you, my dear Summerlee, belongs the honour—­posthumous, alas, but none the less unique—­of having given a name to the universal destroyer, the Great Gardener’s disinfectant.  The symptoms of daturon, then, may be taken to be such as I indicate.  That it will involve the whole world and that no life can possibly remain behind seems to me to be certain, since ether is a universal medium.  Up to now it has been capricious in the places which it has attacked, but the difference is only a matter of a few hours, and it is like an advancing tide which covers one strip of sand and then another, running hither and thither in irregular streams, until at last it has submerged it all.  There are laws at work in connection with the action and distribution of daturon which would have been of deep interest had the time at our disposal permitted us to study them.  So far as I can trace them”—­here he glanced over his telegrams—­“the less developed races have been the first to respond to its influence.  There are deplorable accounts from Africa, and the Australian aborigines appear to have been already exterminated.  The Northern races have as yet shown greater resisting power than the Southern.  This, you see, is dated from Marseilles at nine-forty-five this morning.  I give it to you verbatim:—­

“`All night delirious excitement throughout Provence.  Tumult of vine growers at Nimes.  Socialistic upheaval at Toulon.  Sudden illness attended by coma attacked population this morning. peste foudroyante.  Great numbers of dead in the streets.  Paralysis of business and universal chaos.’