It has been demonstrated that amanitin separates very readily from lecithin during the _decay or careless drying_ of mushrooms and changes into the _poisonous neurin_; hence the necessity of using mushrooms only when _perfectly fresh_ or when _quickly dried_. MUSCARIN.[A] [A] The earliest account of the separation of the poisonous principles of the mushrooms of the genus Amanita dates back to the experiments of Apoiger in 1851. Harnack's researches were published in 1876 and those of Huseman in 1882. To the eminent German chemists Schmiedeberg and Koppe is due the credit of isolating the active poisonous principle of the Fly mushroom (_muscarin_). These authors published in 1869 a series of interesting experiments made with _muscarin_, having relation to its effect upon the heart, respiration, secretions and digestive organs, etc., and this was supplemented by other experiments made by their pupils, Prof. R. Boehm and E. Harnack. Schmiedeberg and Koppe's work relates to the effect of this poison on man as well as upon the lower animals. Dr. J. L. Prevost in 1874 reviewed the investigations made by Schmiedeberg and Koppe in a paper read before the Biological Society of Geneva, adding some confirmatory observations of his own relative to experiments made with muscarin upon the lower animals. The experiments made by these authors demonstrated "that muscarin arrests the action of a frog's heart, that a muscarined frog's heart began to beat immediately under the influence of atropin, and further that it was impossible to muscarine a frog's heart while under the influence of atropin." Schmiedeberg subjected cats and dogs to doses of muscarin, large enough to produce death, and when the animals were about to succumb, injected hypodermically from one to two milligrams of sulphate of _atropin_, after which the toxic symptoms disappeared and the animals completely revived. Prof. Boehm found that _digitalin_ likewise re-established heart action when suspended by the action of muscarin. In man the fatal termination, in cases of mushroom poisoning, where the antidote is not used, may take place in from 5 to 12 hours or not for two or three days.