Apart from the business he had with the analyst, Mr. Mole always enjoyed his visits to Wardour Street. Those who had once met Newberry Sones and his witty, clever sister Mary, in that hospitable home of theirs in Mulberry Lane, were always glad to go again; and so in the course of a few years they had gathered round them a society of charming people, in whose company the hours flew pleasantly by with high talk of poetry, literature, and with the refining influences of art and music. Mr. Mole found plenty of food for discussion and investigation in the mushroom question, and Sones had worked at little else of late than the isolation of the alkaloids in fungi. His laboratory had long been stocked with baskets full of agarics, morels, and puff-balls; every known poisonous species which collectors could bring in was rigidly submitted to analysis. Especial attention was directed by Mr. Mole to the species which are commonly eaten in Prussia and Russia, but which are never eaten in France, and to those which, though eaten with impunity in France, are considered poisonous in England. The great questions they desired to settle were the circumstances that modify the action of fungi, _e.g._ cooking, idiosyncrasy, climate, weather, and seasons; all of which are known very greatly to influence the behaviour of mushrooms in the human stomach. Dr. Sones had nothing to do with the physiological part of the question, and Mr. Mole was dependent mainly for the chemical side of the business on Sones. When Mr. Crowe started on his annual holiday, the various poisonous alkaloids in the fungi had just been isolated by our chemist, and it only awaited a series of experiments on animals to verify the facts which had been discussed relative to their operation. During his absence Dr. Sones had prepared a considerable quantity of these deadly poisons for the use of his friend. The porter at St. Bernard’s had collected a sufficient number of animals of various ages and sizes for Mr. Mole, so that nothing was wanting but the remaining links in the chain of proof to settle once and for all the great question of the causes of mushroom poisoning. One terrible fact greatly impressed Dr. Sones as the result of these determinations: namely, that if the poisonous alkaloid became readily procurable, nothing would be easier than for a criminal to prepare a dish in such a manner that the eater thereof would die, without much chance of detection, owing to the bad reputation of the fungi for terminating life suddenly. He laboured, therefore, long and anxiously to find some reagent or means of detecting the presence of the different alkaloids he had discovered which were capable of causing death in the human species; but hitherto without success.