Page:Treatise on poisons in relation to medical jurisprudence, physiology, and the practice of physic (IA treatiseonpoison00chriuoft).pdf/708

 fungi as articles of food are liable to considerable variety. Some, which are in general eaten in safety, occasionally become hurtful; and some of the poisonous kinds may under certain circumstances become inert, or even esculent. But the causes which regulate these variations are not well ascertained.

It has been thought by some that most fungi become safe when they have been dried; and there may be some truth in this remark, as their poisonous qualities appear to depend in part on a volatile principle. But it is by no means universally true. Foderé mentions that the Agaricus piperatus continues acrid after having been dried.

Climate certainly alters their properties. The Agaricus piperatus is eaten in Prussia and Russia; but is poisonous in France. The Agaricus acris and A. necator, also enumerated above as meriting their names, are used freely in Russia. The Amanita muscaria in France and Britain is a violent poison, and is considered so even in Russia; but in Kamschatka it yields a beverage which is used as a substitute for intoxicating liquors.

There is some reason to believe also that the weather or period of the season influences some of the esculent species. Thus Foderé has mentioned instances of the common morelle having appeared injurious after long-continued rain.

Even the Agaricus campestris or common mushroom is generally believed to become somewhat unsafe towards the close of the season, or as it turns old. Its external characters at that time are sensibly altered; the margin of the cap is more acute, its white colour less lively, and the fleshy hue of its lamellæ is changed to brown or black. In this state, however, I have often eaten it freely and with impunity.

Cooking produces some difference on their effects. The very best of them are indigestible when raw; and some of the poisonous species may lose in part their deleterious qualities when cooked, because heat expels the volatile principle; but, on the whole, I believe the effect of cooking has not been satisfactorily shown to be considerable. Dr. Pouchet of Rouen seems to have clearly proved, that the poisonous properties of two of the most deadly fungi, the ''Amanita muscaria and A. venenata'', may be entirely removed by boiling them in water. A quart of water, in which five plants had been boiled for fifteen minutes, killed a dog in eight hours, and again another in a day; but the boiled fungi themselves had no effect at all on two other dogs; and a third, which had been fed for two months on little else than boiled amanitas, not only sustained no harm, but actually got fat on this fare. Pouchet is inclined to think that the whole poisonous plants of the family are similarly circumstanced.—On the other hand some cryptogamous botanists have maintained that the