OCR Text |
Show 86 PARTICULAR CONSIDERATIONS ON THE form1ble to that principle, acknowleged to be so generally visible in the affairs of Providence, to have all done by the employment of the smallest possible amount of means Thus, as one set of laws produced all orbs and their mo. tions and geognostic arrangements, so one set of law* oversvread them all with life. The whole productive 01 creative arrangements are therefore in perfect unity. PARTICULAR CONSIDERATIONS RESPECTING THE ORIGIN OF ANl~fATED TRIBES. THE general likelihood of an organic creation by law having been shown, we are ne:xt to inquire if science has any facts tending to bring the assumvtion more nearly home to nature. Such facts there certainly are; but it cannot be surprising that they are comparatively few and scattered, when we consider that the inquiry is into one of nature's profoundest mysteries, and one which has hitherto engaged no direct attention in almost any quarter. Crystallization is confessedly a phenomenon of inorganic matter; yet the simplest rustic observer is struck by the resemblance which the examples of it left upon a window by frost bear to vegetable forms. In some crystallizations the mimicry is beautiful and complete; for exanlple, in the well known one called the Arbor Diant:e. An an1algam of four parts of silver and two of mercury being dissolved in nitric acid and water equal to thirty weights of the metals being added, a small piece of soft amalgam ()f silver suspended in the solution, quickly gathers to itself the particles of the silver of the amalgam, which fortn upon it a crystallization precisely resembling a shrub. The experiment may be varied in a way which serves better to detect the influence of electricity in such operations, as noted below.* Vegetable figures are also pre- .. "A glass tube is to be bent into a syphon, and placed with tho curv~ downwards, and in the bend is to be placed a small portion of mercurr, not sufficient to close the connexion between the two legs; a solution of nitrate of silver is then to be introduced until it rises in both limbs of the tube. 'l'he precipitation of the mercury, in the form of an Arbor Dianre, will then take place, slowly, only when the syphon is placed in a plane perpendicular to the magnetic meridian ; but if it be placed in a plane coinciding with the mag· !letic meridian, the action is rapid, and the crystallization particu ... ORIGIN OF THE ANIMATED TRIBE~. 87 'ente~ in ~orne of the most ordinary appearances of the ~lectr~c fi~Id. In t~e ~narks caused by positive elt·ctricity, Dr whiCh It leaves In Its passage, we see the ramifications '>f a tree as well as of its individual leaves; those of the negative, recall the bulbous or the spreading root, according as they are clumped or divergent. These phenomena seem to say that the electric energies have had something to do in determining the forms of plants. That they are intimately connected with vegetable life is indubitable, for germination will not proceed in water charged with negative electricity, while water charged positively greatly favors it; and a garden sensibly increases in luxuriance, when a number of conrlucting rods are made to terminate in branches over its beds. With regard to the resemblance of the ramifications. of the branches and leaves of plants to the traces of the positive electricity, and that of the roots to the negative, it is a circumstance calling for espP-cial remark, that the atmosphere, particularly its lower strata, is generally charged po~itively~ while the earth is always charged negatively. The correspondencP here is curious. A plant thus appears as a thing formed on the basis of a natural electrical operation-the brush realized. We can thus suppose the various forms of plants as, immediately, the result of a law in electrjcity variously affecting them according to their organic character, or respective germinal constituents. In the poplar, the brush is unusually vertical, and little divergent; the reverse in the beech; in the palm, a pencil has proceederl straight up for a certain distance, radiates there, and turns outwards and downwards ; and so on. We can here see at least traces of secondary means by which the A !mighty Deviser might establish all the vegetable forms w 1th which the earth is overspread. Vegetable and animal bodies are mainly composed of the same four simple substances or elements-carbon, oxygen, hydrogen, and nitrogen. The first combinations of these in animals are into what are called proximate principles, as albumen, fibrin, urea, alantoin, &c., out of which the structure of the animal body is composed. larly beautiful, taking place principally in that branch of the sy. phon t.owards the north. If the syphon.be placed in a plane per· pcndicular to the magnetic meridian, and a strong magnet brought ncar it, the precipitation will commence in a short time, and be most copious in the branch of the syphon nearest to the south pole ~f the magnet.,, |