One day, when visiting Janet at her aunt’s home by appointment, Mr. Mole confided to her his desire to know what those foreign boxes contained which he had discovered at the laboratory, and asked her if she had ever observed such things in her master’s rooms? Spriggs said she had not noticed them, but would oblige him by keeping a sharp look-out; and shortly after, to his great delight, she handed him one which she had abstracted from a cupboard in the study. It was empty, but Mr. Mole took it home with a view to closer scrutiny. In the corner of the box, which was of thin deal, he found a brown powder, which he subjected to careful microscopical examination, and was not long in proving to his complete satisfaction that it consisted of the spores of some mushroom, of a species which he was not precisely able to determine. However, he had satisfied himself that certain kinds of Russian fungi were imported by Mr. Crowe for some mysterious purpose. Some months after this he was on a visit to the kitchen when the other servants were absent temporarily, and Spriggs was preparing for her mistress a small dish of stewed mushrooms, of which she was able to partake with more relish than she showed for her other food. Spriggs told him that her master had ordered her to let her mistress have them as often as she liked, as they were very good for her complaint. He did not at the time attach any importance to this discovery; but when a few days after a case of mushroom poisoning of a whole family was reported at the hospital, he remembered the circumstance, and took copious notes of the cases. In the college Library he turned up from the files of the _Lancet_ all the cases he could find of poisoning by fungi, and soon had a very clear idea of the peculiar symptoms of such cases, after which he began a course of experiments for himself. At first he thought Mr. Crowe was engaged on some monograph on the subject that was to bring him distinction, especially as he noticed in the wards set apart to his principal’s cases, symptoms more or less severe, which he had no doubt were due to small doses of some such agent as _Muscarin_, _Lorchelin_, or _Bulbosin_, the active principles of poisonous mushrooms. On examining the prescriptions for the medicines which these patients were taking, he found that his ideas were correct, and that Mr. Crowe had been exhibiting these poisons in minute doses to all of them. He made no remark, but obtaining a supply from the dispenser, tried their effect in various doses on a number of animals which he kept for such purposes in one of the subterranean chambers under the pathological rooms. It was not long before Mr. Mole was in possession of quite a fund of information relating to the use of these potent drugs.