more than those here recorded; but as I have not hitherto myself made trial of any others, and as there are some dangerous species mixed up with this group, the public cannot be too much cautioned against making any rash experiment, where the consequences of a mistake might be so serious. Some trees give origin by preference to good, others to deleterious species; thus, the hazel-nut, the black and perhaps the white poplar, together with the fig-tree, grow only good sorts; whereas the olive has been famous, since the days of Nicander, for none but poisonous species. “The rank in smell, and those of livid show, All that at roots of oak[90] or olive grow, Touch not! But those upon the fig-tree’s rind Securely pluck—a safe and savoury kind!” The elm, the alder, the larch, the beech, and some other trees, seem capable of supporting both good and bad species at their roots; hence it is not safe to trust implicitly to the _tree_ to determine the wholesomeness or unwholesomeness of the fungus that grows out of it, or in its neighbourhood. The presence of a _free acid_ is by no means conclusive either way, there being many species of both good and bad, which will indifferently turn litmus-paper red. The old and very general practice adopted by cooks of _dressing funguses with a silver spoon_ (which is supposed to become tarnished, then, only when their juices are of a deleterious quality), is an error which cannot be too generally known and exposed, as many lives, especially on the Continent, have been, and still are, sacrificed to it annually. In some cases the kitchen-fire will extract the deleterious property from the funguses, which it would have been unsafe to eat raw, and frequently the acrid lactescent kinds change their nature entirely and become mild by cooking; in other cases, the virus is drawn out by saturating the fungus, sometimes before dressing it, either in vinegar or brine,[91] the liquid then containing the poison which was originally in the plant; but in other species, as in _Ag. emeticus_, it would seem from the experiments of M. Krapf, of Vienna, upon living animals, that it is to be extracted neither by ebullition nor desiccation.[92]