Doctrine of Progressive Improvement.

351

added or juxtaposed to the old, but evolved or developed from it. From the homogeneous or general, the heterogeneous or special is brought forth. A new member, fashioned in secrecy and apart, is never abruptly engrafted on any living thing. New animal types have never been suddenly located among old ones, but have emerged from them by process of transmutation. As certainly as that every living thing must die, so must it reach perfection by passing through a succession of subordinate forms. An individual, or even a species, is only a zoological phase in a passage to something beyond. An instantaneous adult, like an immortal animal, is a physiological impossibility.

trine of

ment.

This bringing forth of structure from structure, of function The docfrom function, incidentally presents, upon the whole, an ap- progressive pearance of progressive improvement, and for such it has been improvenot unfrequently mistaken. Thus, if the lowest animals, which move by reflex action, instantly but unconsciously, when an impression is made upon them, be compared with the higher ones, whose motions are executed under the influence of antecedent impressions, and are therefore controlled by ideas, there seems to have been such an improvement. Still, however, it is altogether of a physical kind. Every impression of which the dog or elephant is conscious implies change in the nerve centres, and these changes are at the basis of the memory displayed by those animals. Our own experience furnishes many illustrations. When we gaze steadfastly on some brightlyilluminated object, and then close or turn aside our eyes, a fading impression of the object at which we have been looking still remains; or when a spark is made to revolve rapidly, we think we see a circle of fire, the impression upon the retina lasting until the spark has completed its revolution. In like manner, though far more perfectly, are impressions registered or stored up in the sensory ganglia, the phantoms of realities that have once been seen. In those organs countless images may thus be superposed.

between

Man agrees with animals thus approaching him in anatomi- Analogies cal construction in many important respects. He, too, repre- animals sents a continuous succession of matter, a continuous expen

and man.

Points of

distinction between them.

The human soul.

352

Analogies, and Points of Distinction

diture of power. Impressions of external things are concealed in his sensory ganglia, to be presented for inspection in subsequent times, and to constitute motives of action. But he differs from them in this, that what was preparatory and rudimentary in them is complete and perfect in him. From the instrument of instinct there has been developed an instrument of intellection. In the most perfect quadrupeds, an external stimulus is required to start a train of thought, which then moves on in a determinate way, their actions indicating that, under the circumstances, they reason according to the same rules as man, drawing conclusions more or less correct from the facts offered to their notice. But, the instrument of intellection completed, it is quickly brought into use, and now results of the highest order appear. The succession of ideas is under control; new trains can be originated not only by external causes, but also by an interior, a spontaneous influence. The passive has become active. Animals remember, man alone recollects. Everything demonstrates that the developement and completion of this instrument of intellection has been followed by the superaddition of an agent or principle that can use it.

There is, then, a difference between the brutes and man, not only as respects constitution, but also as repects destiny. Their active force merges into other mundane forces and disappears, but the special principle given to him endures. We willingly persuade ourselves that this principle is actually personified, and that the shades of the dead resemble their living forms. To Eastern Asia, where philosophy has been accustomed to the abstract idea of force, the pleasures we derive from this contemplation are denied, the cheerless doctrine of Buddhism likening the life of man to the burning of a lamp, and death to its extinction. Perceiving in the mutation of things, as seen in the narrow range of human vision, a suggestion of the variations and distribution of power throughout nature, it rises to a grand, and, it must be added, an awful conception of the universe.

But Europe, and also the Mohammedan nations of Asia, have not received that view with approbation. To them there

is an individualized impersonation of the soul, and an expectation of its life hereafter. The animal fabric is only an instrument for its use. The eye is the window through which that mysterious principle perceives; through the ear are brought to its attention articulate sounds and harmonies; by the other organs the sensible qualities of bodies are made known. From the silent chambers and winding labyrinths of the brain the veiled enchantress looks forth on the outer world, and holds the subservient body in an irresistible spell.

of these

nature of

This difference between the Oriental and European ideas Extension respecting the nature of man reappears in their ideas respect- views to the ing the nature of the world. The one sees in it only a gigan- the world. tic engine, in which stars and orbs are diffusing power and running through predestined mutations. The other, with better philosophy and a higher science, asserts a personal God, who considers and orders events in a vast panorama before Him.

2 A

VOL. II.

Analogies between the Age of Rea

son in Eu

Greece.

CHAPTER XXV.

THE EUROPEAN AGE OF REASON-(Continued).

THE UNION OF SCIENCE AND INDUSTRY.

HE Age of Reason in Europe presents all the peculiarities of the Age of Reason in Greece. There are modern rope and in representatives of King Ptolemy Philadelphus among his furnaces and crucibles; of Hipparchus cataloguing the stars; of Aristyllus and Timochares, with their stone quadrants and armyls, ascertaining the planetary motions; of Eratosthenes measuring the size of the earth; of Herophilus dissecting the human body; of Archimedes settling the laws of mechanics and hydrostatics; of Manetho collating the annals of the old dynasties of Egypt; of Euclid and Apollonius improving mathematics. There are botanical gardens and zoological menageries like those of Alexandria, and expeditions to the sources of the Nile. The direction of thought is the same; but the progress is on a greater scale, and illustrated by more imposing results. The exploring voyages to Madagascar are replaced by circumnavigations of the world; the revolving steam-engine of Hero by the double-acting engine of Watt; the great galley of Ptolemy, with its many banks of rowers, by the ocean steamship; the solitary watch-fire on the Pharos by a thousand lighthouses, with their fixed and revolving lights; the courier on his Arab horse by the locomotive and electric telegraph; the scriptorium in the Serapion, with its shelves of papyrus, by countless printing-presses; the 'Almagest' of Ptolemy by the 'Principia' of Newton; and the Museum itself by English, French, Italian, German, Dutch, and Russian philosophical

Discoveries respecting the Atmosphere.

355

societies, universities, colleges, and other institutions of learning.

progress in

of know.

So grand is the scale on which this cultivation of science European has been resumed, so many are those engaged in it, so rapid the acquisiis the advance, and so great are the material advantages, that ledge. there is no difficulty in appreciating the age of which it is the characteristic. The most superficial outline enables us to recognize at once its resemblance to that period of Greek life to which I have referred. To bring its features into relief, I shall devote a few pages to a cursory review of the progress of some of the departments of science, selecting for the purpose topics of general interest.

First, then, as respects the atmosphere, and the phenomena connected with it.

From observations on the twilight, the elasticity of aerial The atmo. sphere. bodies, and the condensing action of cold, the conclusion previously arrived at by Alhazen was established, that the atmosphere does not extend unlimitedly into space. Its height is considered to be about forty-five miles. From its compressibility, the greater part of it is within a much smaller limit; were it of uniform density, it would not extend more than 29,000 feet. Hence, comparing it with the dimensions of the earth, it is an insignificant aerial shell, in thickness not the eightieth part of the distance to the earth's centre, and its immensity altogether an illusion. It bears about the same proportion to the earth that the down upon a peach bears to the peach itself.

A foundation for the mechanical theory of the atmosphere was laid as soon as just ideas respecting liquid pressures, as formerly taught by Archimedes, were restored, the conditions of vertical and oblique pressures investigated, the demonstration of equality of pressures in all directions given, and the proof furnished that the force of a liquid on the bottom of a vessel may be very much greater than its weight.

nical rela

Such of these conclusions as were applicable were soon trans- Its mechaferred to the case of aerial bodies. The weight of the atmo- tions. sphere was demonstrated, its pressure illustrated and measured ; then came the dispute about the action of pumps, and the over