« 上一頁繼續 »
By the word Nature, derived from a term signifying born, or produced, in a general sense we mean all the works of God. Using a figure of speech called Metonomy, we often put the effect for the cause ; as, when we speak of the “works of nature,” meaning what the Almighty has brought forth, or we often mean by nature the Deity himself: as when we say that “nature produces plants and animals.'
With respect to the heavenly bodies, which manifest themselves to us with so much magnificence, we know them to be matter, because we observe them to be subject to the laws which govern matter ; and we have been able, by the discoveries of astronomers, to understand their various revolutions: we have in general, clearer ideas of their motions than even of our own planet ; it is more easy for us to imagine them as moving, than that our firm earth is whirling with inconceivable velocity. Were it possible for us to conceive the quantity of matter which even one world as large as our sun contains, the thought would be overwhelming; and of all the worlds which we behold at one view in a serene night, what finite being could imagine their united extent? They are suspended over our heads, each one pursuing its destined course: why do we not fear that some one may be precipitated upon our little world, and crush it to atoms? It is because we know that they are all upheld by that Power which “created the heavens and the earth,” and who governs the universe by regular laws. This universe is infinite as the God who formed it ; our sun, with all its systems, is but a point lost in immensity. Astronomers have proved that the fixed stars are at such an immense distance from us, that moving at the rate of 500 miles an hour, we should not reach the near. est of them in 700,000 years, a distance of more than 200,000 times greater than that of the sun from the earth. The same space probably separates all the fixed stars. Around those stars revolve millions of opaque globes, as our earth revolves around the sun, which is also one of the fixed stars. The satellites describe around the primary planets almost circular orbits; they are carried with their primaries around the sun in their annual motion ; the sun himself, with all his numerous train of primary planets, each with its satellites, revolves around the common centre of gravity of the fixed stars, of which himself constitutes a part ; and these are supposed to revolve around the centre of the universe. Here may be the throne of the Almighty Creator and Director of all these stu. pendous objects.
Yet we need not fear that we shall be forgotten in the im. mensity of creation ; the same Being who created and rules
Definition of Nature-The heavenly bodies.
the host of heaven, made the little moss and the lilies of the field, which are so beautifully arrayed. If God condescends to care for them, he will not neglect us who are made in his own image, and destined to an immortal existence.
Turning our thoughts from the heavenly host to our own little globe, and considering the matter which exists upon it, we find two great classes of substances : 1st, inorganized, and 2d, organized.
The 1st class of substances, viz : such as are inorganized, comprehends all matter destitute of a living principle; such as fluids, gases, and minerals. The particles which compose them are entirely subject to chemical and mechanical laws.
The 2d class, viz: organized substances, includes animals and vegetables ; the particles constituting them are in a perpetual state of motion. They are supported by air and food, endowed with life, and subject to death ; the active power or life which operates in them we call the vital principle. This vital principle eludes the researches of man; all that we know of it is in its effects, enabling the organized body to resist putrefaction, and, to a certain degree, to maintain a temperature different from surrounding bodies. Deprived of this vital principle, both animals and vegetables become subject to chemical decomposition ; their solid parts are dissolved, and they return to the earth from whence they were taken.
If you dig up a stone, and remove it from one place to another, it will suffer no alteration; if you dig a plant it will wither and die. If you break a mineral to pieces, every fragment will be a perfect specimen of its kind; it will only be altered in shape and size ; but if you tear off a branch from a plant, or if a limb is taken from an animal, they will both immediately begin to decay; the vital principle being extinguished, putrefaction and dissolution follow.
We should never have been able to predict, from the appearances of the stone, the plant, and animal, that they were thus differently constituted; by observations we find, that the production and mode of growth, has been under different circumstances. We find that the stone has grown by a gradual accumulation of particles, independent of each other, and can only be destroyed by chemical or mechanical force; the plant and animal, have on the contrary, grown by nourishment, been possessed of parts mutually dependent, and con. tributing to the existence of each other.
So far, our observation teaches us the distinction between organized and inorganized beings; though it does not teach
Substances divided into two classes - 1st class of substances-2d class of substances-Vital principle-Difference between a stone and a plant.
us in what this internal power, or life consists. God permits us to know much, in order to lead us to industry in the attainment of knowledge ; but he places boundaries beyond which we may not pass, that we may be humble.
Comparison of the Organic and Inorganic Kingdoms.
Their parts always analo. Their parts are mutually gous to, and not depending on dependent; thus a stem, leaf, each other; thus a fragment | flower, &c. do not constitute of stone, is as much a stone a vegetable being, except as as the block or rock to which they are united; it is the same it belonged.
with the different parts of an
Origin. Molecular attraction, mod. Owe their existence to be. ified by time and space, or ings similar to themselves, by the art of man (as in produced either from eggs, or chemistry); they are made. brought into existence in a
living state ; they are hatched
Developement. They grow by the addition They develope by assimilaof new particles; they are ting to their nature, or conhence said to increase by verting to their sustenance, juxtaposition or accretion. foreign substances which they
absorb, or receive internally ;
they increase by nourishment.
Termination. They are limited to no par- They have a determinate ticular form (except in the form, and duration ; their excase of crystals), they have istence terminates either by no life, and are not subject to old age, or disease; they die. death; they decompose.
Having considered the distinction between inorganic and organic substances, we will proceed to a division which may
Structure of inorganic bodies – Of organic bodies-Origin of inorganic bodies--Of organic bodies—Developement of inorganic bodies–Of organic bodies-- Termination of inorganic bodies–Of organic bodies.
be more familiar to you ; that by which the matter upon our globe is ranged under three kingdoms; the ANIMAL, VEGETABLE, and MINERAL.
We find it somewhat difficult to draw a line of distinction between the different kinds of organized beings, viz. animals and vegetables ; the lines of distinction often seem to fade so gradually, that we cannot well decide where the animal ends, and the vegetable begins.
This difficulty may seem at first somewhat strange, as you may perhaps never have been at a loss to tell an animal from a vegetable ; you would certainly know how to distinguish between a nightingale and a rose, or between an ox and an oak; but these are animals and vegetables in a comparatively perfect state.
The animal you see has the power to move about, to seek the nourishment most agreeable ; you perceive it uttering audible sounds, possessing sensation and apparent consciousness. The plant on the contrary is confined to a particular spot, having no other nourishment than substances which themselves come in contact with it; exhibiting no consciousness, nor to common observation any sensation. It is only, when we examine with close attention, the various phenomena in the vegetable and animal kingdoms, that we learn to doubt, as to the exact boundaries by which they are separated.
The division of nature into three kingdoms, animal, vegetable and mineral, is very ancient, and appears at first to be clear and precise.
Minerals destitute of life increase by the accumulation of new particles.
Vegetables grow, produce seeds which contain the elements of future plants like themselves, and then die.
Animals unite to the properties of vegetables, the feeling of their own existence; or as Linnæus has said, “ Stones grow, vegetables grow and live, animals grow, live, and feel.” Al. though this simple view of the works of creation is pleasing, it is not satisfactory ; because we are not able to decide where in the vast series of organized beings, sensation ceases.
That you may the better understand what is meant by the gradations in animal life, we will present you with a sketch of the classification of animals. The study of this department of nature you have already been told is termed Zoology.
A very general and simple classification of animals is as follows:
Three kingdoms of nature- Distinction between the different kinds of or. ganized beings - Minerals — Vegetables—Animals—Zoology-Division of ani. mals into two classes.
“ Vertebral, animals having backbones. Avertebral, animals destitute of backbones. VERTEBRAL animals are divided into, 1. Quadrupeds. The science of which has no popular
It includes four-footed animals; as ox, dog, mouse. 2. Birds. The science of which is called ornithology. It includes the feathered tribe; as pigeon, goose, wren.
3. Amphibious Animals. The science of which is called amphibiology. It includes those cold blooded animals which are capable of living on dry land, or in the water; as tortoise, lizard, serpent, frog.
4. Fishes. The science of which is called itchthyology. It includes all aquatic animals which have gills and fins; as shad, trout, sturgeon, eel.
AVERTEBRAL animals are divided into,
5. Insects. The science of which is called entomology. It includes all animals with jointed bodies, which have jointed limbs; as flies, spiders, lobsters.
6. Vermes. The science of which is called herminthology. It includes all soft animals of the avertebral division, which have no jointed limbs, with or without hard coverings; as angle worms, snails, oysters, polypi, and infusory animals."*
The system of Zoology most approved, is the one taught by Linnæus, with some improvements made by the great French naturalist, Cuvier; according to this mode of classification, the animal kingdom is divided into four grand divisions, viz:
VERTEBRAL, MOLLUSCOUS, ARTICULATED, and RADIATED. These are subdivided into classes and orders.
First Grand Division- Vertebral Animals. CLASS 1.
Mammalia, or such as at first are nourished by milk. This class have lungs, and peculiar organs for imbibing their food, during their first stage of existence.
The First Order is called Bi-mani (from bis two, mani hands); this order includes man only ; we find here no generic or specific differences, but the following varieties.
1st. Caucasian race, anciently inhabiting the country about the Caspian and Black Seas, from whom we are descended.
2d. The Mongolian, the ancient inhabitants about the Pacific Ocean, from whom the Chinese are descended.
3d. The Ethiopian, or Negro race. The second order contains the quadru-mani, from quatuor
* Eaton's Zoology.
How many classes of Vertebral animals ?-How are Avertebral animals divided ?-Cuvier's four grand divisions--1st class of vertebral animals-Order bi-mani-Varieties in this order-Order quadru-mani.