The group of Russulæ, most of which are esculent, is notable for their gills of even length (18), though not all the species are thus characterized. This discrimination, however, especially applies to the Shaggy-mane ([Plate 16]), which is conspicuously even-gilled, and is a decided delicacy.
This species, together with its congener, the edible Coprinus atramentarius ([Plate 17]), are notorious for their melting into black fluid (19), which is thus of no significance as a test, although the mushrooms are not supposed to be eaten in this stage of deliquescence.
A fungus which bites the tongue (20) when tasted would naturally be excluded from our mushroom diet, as would also, of course, those of a bitter or nauseating taste; but several species, notably the Lactarius piperatus, as its name implies, is very hot and peppery when raw—a characteristic which disappears in cooking, after which it is perfectly esculent. The same applies in a scarcely less degree to the Agaricus melleus, and less so to the Hydnum repandum ([Plate 27]), and other mushrooms. But the poisonous Russula emetica ([Plate 13]) gives this same hot, warning tang, and this rule (17) would at least thus exclude the harmful species, and is thus contributive to popular safety.
Worthless popular tests
The salt test (21), with that of the silver charm, is also a relic of the dim past, but is absolutely useless as a touchstone. Many poisonous species, notably the Amanita, fail to answer to it. All authorities agree, however, that the addition of salt in cooking, or the preparatory soaking of specimens in brine, has a tendency to render poisonous species innocuous. Indeed, it is claimed that in Russia and elsewhere on the Continent many admittedly poisonous species, even the deadly Fly Amanita, is habitually eaten subsequent to this semi-corning process, by which the poisonous chemical principle is neutralized.
Omission of the only true test
Among this long list, and many other equally arbitrary and ignorant prejudicial traditions, many of which date back to the earliest times, it is indeed astonishing to note the conspicuous absence of the one and only valuable sign by which the fatal species could be unmistakably determined—a symbol which was reserved for botanical science to discover: the presence of the "cup" in the Amanita, which is pointedly emphasized in my Frontispiece, and the importance of which as a botanical and cautionary distinction is considered at more length in the following chapter.
It is well to consider for a moment what is implied in
"A POISONOUS MUSHROOM"
A fungus may be poisonous in various ways:
1. A distinct and certain deadly poison.
2. The cause of violent digestive or other functional disturbance, but not necessarily fatal.
3. The occasion of more or less serious physical derangement through mere indigestibility.
4. Productive of similar disorders through the employment of decayed or wormy specimens of perfectly esculent species.
5. These same esculent species, even in their fresh condition, may become highly noxious by contact or confinement with specimens of the Amanita by the absorption of its volatile poison, as further described on [p. 69.]