this is in small proportion; and as, in most of them, the gummy matter is prepared first, requiring for its formation only a moderate degree of light and heat, while the bitter, or other principle, is added at a later period, under the influence of stronger light; such plants, when young, are tender and agreeable; nay, even very poisonous plants, when very young, are wholesome and pleasant, which, at a more advanced season, are virose and disagreeable. Thus, the peasantry of France and Piedmont eat the young crowfoots (ranunculus) and poppies, after boiling them, and find them safe and nourishing. The same result follows exclusion of light, as in the process of blanching, by which means celery, sea-kale, and other vegetables, are rendered esculent, which in the wild state are poisonous or repulsive. In northern latitudes, the light being intense for a short time only, many plants are used there which, in the southern, are dangerous or destructive, such as hemlock and monkshood. A moderate degree of bitterness is a very useful accompaniment of the gum, which alone is cloying and even oppressive to the stomach. The presence of a bitter principle in many lichens promotes their digestion, and thus even the tough and leathery ones, called tripe of the rocks, can be eaten, and sustain life amid great privations and sufferings. The rein-deer moss (_cludonia rangiferina_) is another lichen of great utility: it is not much employed as human food, but it is the main support of the rein-deer for a great portion of the year, and thus renders Lapland a fit abode for man. A peculiar modification of gum constitutes _pectine_ or vegetable jelly; and this occurs in fruits, such as the orange, currant, and gooseberry, &c., also in many of the algae or sea-weeds, which are, or ought to be, much employed as a delicate article of nourishment. The edible swallow's nest, so greatly esteemed by the Chinese, is an alga, gathered by the birds. The Ceylon moss (_Gigartina lichenoides_), and the carrageen or Irish moss (_Chondrus crispus_), with many others, might be made to contribute largely to the subsistence of man. Not merely earth, from its fruitful bosom, but the vast ocean, offer their rich produce to nourish and sustain the only intelligent occupant of the globe, who should ever remember the declaration of the psalmist, "O Lord! how manifold are thy works! in wisdom hast thou made them all: the earth is full of thy riches; so is the great and wide sea!" (Ps. civ.) FOOTNOTES: [A] The Greeks used to say that reeds had contributed to subjugate a people, by furnishing arrows; to soften their manner, by the charm of music; and to develop their intelligence, by offering them the instruments proper for the formation of letters.--_Humboldt's Personal Narrative._