In such as you, That creep like _shadows_ by him, and do sigh At each his needless heavings. And again-- Feast-won, fast-lost, one cloud of winter showers. These _flies_ are couched. While climate points out the most suitable articles of food, it exercises a singular influence over their qualities and properties, more especially in vegetable substances. We find plants which are poisonous in some countries, edible and wholesome in others. Next to climate, culture and soil modify plants to a singular degree: flowers which yield a powerful perfume in some latitudes, are inodorous in others; and, according to climate, their aroma is pleasant or distressing. A striking proof of this fact can be adduced from the well-known effects of perfumes in Rome; where the inhabitants, especially females, cannot support the scent even of the rose, which has been known to produce syncope, illustrating the poet's line to Die of a rose in aromatic pain. This variety in the action of vegetable substances is more particularly observable in such as are considered medicinal. Opium, narcotics, and various drugs, are more powerful in warm climates than in northern regions. The Italian physicians express astonishment at the comparatively large doses prescribed by our practitioners. Cultivation brings forth singular intermediate productions; and by its magic power we have seen the coriaceous and bitter almond transformed into the luscious peach, the sloe converted into the delicious plum, and the common crab transformed into the golden pippin. The same facts are observed in vegetables; the celery sprung from the nauseous and bitter _apium graveolens_, and the colewort, is metamorphosed into the cabbage and the cauliflower. All cruciform plants degenerate within the tropics, but acquire increased energies in cold countries. Recent experiments in Germany have demonstrated that in times of scarcity, the wood of several trees may be converted into a nutritious substance. The fibres of the beech, birch, lime, poplar, fir, and various other trees, when dried, ground, and sifted into an impalpable powder, constitute a very palatable article of food. If cold water be poured on this ligneous flour, enclosed in a linen bag, it becomes milky, and considerable pressure and kneading is required to express the amylaceous or starchy part of it. Professor Von Buch, in his travels through Norway and Lapland, has fully described the Norwegian _barke brod_. We find the savages scattered along the coast of the great austral continent mixing up a paste of the bark of the gum-tree with the ants and the other insects, with their larvae, which they find in it. Ground dried fish and fish-bones have from time immemorial been converted into bread; Arrianus tells us that Nearchus found several nations on the shores of the Red Sea living upon a bread of this description.