"The root," he says, "is almost insipid; the leaves taste like a saltish herb; there is something sharp and vinegary in the fruit; the whole plant has a narcotic odour. The leaves do not redden turnsole,[29] but the ripe fruit reddens it greatly; whence we may conjecture that the sal-ammoniac contained in this plant is moderated in the leaves by a very considerable portion of fœtid oil and earth, but that the acid portion of the salt is strongly developed in the ripe fruit; so that we must choose our part of the plant according to the purposes we wish to employ it for. The fruits, for instance, are more refreshing, but more repellant, than the leaves, which soften while resolving, cleansing, and absorbing."
We admit that these data leave much to be desired from a chemical point of view. We may well ask, for example, how the illustrious philosopher ascertained the presence of sal-ammoniac in nightshade? But it is not fair to criticise the science of the past, by judging it through the deceitful prism of the science of to-day. We must adopt the methods of our predecessors, when discussing natural productions from all the view-points of their applications.
Dog's-tooth Grass.
In clearing an uncultivated field we uproot a great number of herbaceous plants of different families; but those of the Gramineæ, or Grasses, invariably predominate. They are the trailing roots, or rhizomes, of certain species which have been included under the general denomination of Dog's-tooth. These tenacious and vigorous roots,—so wholesome in various maladies, so injurious to cultivation,—are, whatever certain botanists may say, far from tracing their origin in all cases to the Triticum repens (couch-grass) and Panicum dactylon—those terrible enemies of the corn-field, which, once established in the soil, are with difficulty extirpated, and prove very injurious to the "golden crops." Nearly every grass which puts forth rhizomes will furnish the Dogs-tooth. We may cite, for instance, several species of Festuca (as Festuca rubra and Festuca pinnata), or fescue grass; at least two kinds of meadow grass (Poa compressa and Poa pratensis), a species of wild-oats (Avena elatior), to say nothing of the weeds Arundo phragmites and Arundo epigeios. The long rhizomes of these vivacious plants possess nearly the same properties, due to their saccharine principles.
Fig. 22.—A Corn-field.
How shall we distinguish these plants from one another? Their leaves have almost exactly the same configuration; they are linear;[30] and their flowers are not apparent,—they do not attract the gaze of the passer-by. Yet they possess all the organs necessary for the reproduction of their species:—three stamens, each composed of an anther and a characteristic filament; on this anther, whose two lobes are arranged like the branches of an X, the pistil softly and tenderly balances itself on the summit of a frail thread, to which it is attached by the back. Remark, too, the two styles with feathery stigmata,[31] like the barbs of feathers. Nothing is wanting to constitute a complete flower.
There is even a perianth, or calyx, represented by a couple of tiny membraneous scales, scientifically known as glumellulæ; then at the base of each spikelet, composed of one or two of these bright green lilliputian flowers, are two other and larger scales, called glumellæ: they represent an involucre.[32] It is almost unnecessary to add, that the free, unilocular ovary, or seed vessel, forms, as a result of its development, the seed, whose embryo adheres laterally to a farinaceous kernel, or perisperm. The union of one or more of these flowers composes a spikelet, and the union of the spikelets constitutes the spike, which may be disposed on a simple or ramified axis. Such are, in general, the characters we must keep before us in the difficult study of the Gramineæ.