“On September 1st, the sea was colored in veins or patches, of a brown color, or sometimes with a yellowish green; and this water, on being examined by the microscope, appeared swarming with minute marine animals. A drop of this water contained twenty-six thousand five hundred animalculæ. Hence, reckoning sixty drops to a drachm, there would be a number in a gallon of water exceeding by one half the amount of the whole population of the globe. It affords an interesting conception of the minuteness of some tribes of animals, when we think of more than twenty-six thousand individuals, living, obtaining subsistence, and moving perfectly at their ease, in a single drop of water!” A sea is required for a whale to spout in; but a common tumbler affords abundant space for a hundred and fifty millions of these little creatures! The phosphorescent appearances presented by them are not, however, without an important design. It is probable that God, whose knowledge is unbounded, foreseeing that man would learn to traverse the mighty deep, and explore the most distant regions of the globe, has given this brightness to the ocean to lessen his dangers, and to render his nights less gloomy. Especially will this seem likely, when it is remembered that it is seen only in the night season, and is vivid in proportion to the darkness. It disappears even before the feeble light of the moon, and increases with the agitation of the sea; so that, during the prevalence of a storm, it generally diminishes the dense gloom, which at such times even the moon and stars cannot penetrate. It casts such a light on the ship and rigging, that the sailors may execute their allotted tasks with certainty, and at all times it points out to the cautious mariner the lurking danger of sunken rocks, shoals and unknown coasts. It is well known that sea animals, larger than those minute creatures of which we have been speaking, have also the power of emitting light. Pliny tells us, that some of the old Romans, in his time, used to sup in darkened apartments upon the _pholas_, a kind of shellfish, which gave out sparks of light, and amused the people, while they gratified their appetites. A traveller in a remote land, speaks of fishes that played around the boats, each being encircled by a halo of light. But the land has its luminous animals, as well as the sea. The glow-worm is common in Europe: this is a female beetle, without wings. It emits a light of a sulphur color, so strong that if placed at night on a page of small print, it may be easily read. In Africa there is an insect that emits light from two globes, like lamps, upon its horns. The fire-fly of South America is very common, and its light is so brilliant as that several put together will enable a person to see to write. The fire-fly of our country, which seems to make the landscape at night sparkle as with a thousand gems, is smaller than that of South America.