Muscarine is an alkaloid contained in the mushroom known as the fly agaric, Amanita muscaria, and in some other agarics. Its actions are very similar to those of pilocarpine, but stronger, hence in poisoning by the fly agaric we get the same symptoms as from pilocarpine poisoning. The symptoms come on very quickly. Muscarine is not destroyed by cooking. Atropine is the best antidote, and the stomach should be washed out or an emetic given, and general treatment for collapse instituted. Muscarine is not used in medicine, as it is more dangerous and more irritant to the stomach than pilocarpine.

Most of the cases of mushroom poisoning, however, are due to the death's-head fungus, Amanita phalloides, and related species, which contain little if any muscarine, but depend for their poisonous action upon a substance which has the nature of a toxin. It is characteristic of a toxin that the symptoms are manifested only after a latent period, and that immunity may be established toward it in susceptible animals by the repeated administration of non-lethal doses. This toxin is destroyed by prolonged cooking. Ford has prepared a serum which is antitoxic and anti-hemolytic to the amanita toxin.

The symptoms come on after a latent period of ten or twelve hours. They are great thirst, vomiting, diarrhea, cramps in the stomach and limbs, headache, cerebral stimulation up to a state of delirium, and sometimes suppression of the urine. After twelve to twenty-four hours there may be jeundice from extensive hemolysis, or collapse from a toxic action upon the heart muscle; or the sickness continues for several days, resembling an infectious disease. Later there may be an interstitial nephritis with uremia.

Fig. 54.

Fig. 54. - Amanita phalloides, white form, showing cap, stem, ring, and cup. (From Atkinson's "Mushrooms," Henry Holt & Co., Publishers.)

Muscarine And Mushroom Poisoning 83

Fig. 55 - Agaricus camper's View of under side, showing stem, ring, gills, and margin of cap. (From Atkinson's "Mushrooms," Henry Holt & Co., Publishers.)

Fig. 56.

Fig. 56. - Fly amanita, Amanita muscaria. Poisonous. Nearly one-half natural size. (From Circular 139, Third Series, U. S. Department of Agriculture.)

The treatment is to wash out the stomach and the colon, apply an ice-bag to the head, and give morphine by hypodermatic. If collapse ensues, treat for collapse. Atropine is of no value, and Ford's serum would hardly be obtainable when wanted.

Ford has attempted to divide the poisonous fungi into three groups, viz.:

1. Those containing poisons acting on the nervous system, as Amanita muscarta.

2. Those producing degenerative changes in the internal organs, as Amanita phalloides, Amanita verna, etc.

3. Those causing gastro-intestinal irritation with violent manifestations, as Lactarius torminosus, Clitocybe illudens, Entoloma sinuatum, etc.

The Amanita muscaria, or fly agaric, is highly colored with yellow and orange and reddish tints. Its stem is longer than the diameter of the cap, bulges at the base, and bears a collar or ring of tissue. The cap is deep yellow or orange or greenish yellow, and bears numerous scattered white or yellow scales. The gills on the under surface of the cap are white. It has a fungous odor and grows in open woods or along roadsides near trees.

The Amanita phalloides (death's-head fungus, deadly agaric) is white throughout or slightly brownish. The stem often arises from a cup - the so-called "death's-head" or "poison-cup" - bulges at the base, is longer than the diameter of the cap, and near the cap is surrounded by a collar of tissue (the annulus or ring); it tends to turn dark where bruised. The cap is white, or slightly yellowish or greenish white, or brownish, and its under surface bears the persistently white gills. It has a typical fungous odor, and grows in open woods or along the borders of woods.

The common edible mushroom or field mushroom is Agaricus campestris. It is stubby in growth. Its stem is shorter than the diameter of the cap, is cylindric, and instead of being bulbous is narrowed at the base; it does not emerge from a cup, and, except for the first hour or two after maturity, is usually without an annulus or ring. Its cap is white to brownish, and bears on its under surface the notably pink gills, which become purplish brown when a few hours old, and turn blackish brown on keeping. It has an earthy smell, like potatoes, rather than a fungous smell, and grows in fields, lawns, or by roadsides.