The Development of the Sciences

Portada
 

Otras ediciones - Ver todas

Términos y frases comunes

Pasajes populares

Página 203 - On the evidence of palaeontology, the evolution of many existing forms of animal life from their predecessors is no longer an hypothesis, but an historical fact ; it is only the nature of the physiological factors to which that evolution is due which is still open to discussion.
Página 222 - I frequently and seriously bethought me, and long revolved in my mind, what might be the quantity of blood which was transmitted, in how short a time its passage might be effected, and the like...
Página 241 - The elementary parts of all tissues are formed of cells in an analogous, though very diversified manner, so that it may be asserted, that there is one universal principle of development for the elementary parts of organisms, however different, and that this principle is the formation of cells.
Página 250 - Nature produces those things which, being continually moved by a certain principle contained in themselves, arrive at a certain end."- What this internal moving * principle is remains to be discovered.
Página 153 - that every particle of matter in the universe attracts every other particle, with a force whose direction is that of the line joining the two, and whose magnitude is directly as the product of their masses, and inversely as the square of their distances from each other.
Página 254 - When species are modified by external causes, they usually degenerate, and do not advance. And there is no instance of a species acquiring an entirely new sense, faculty, or organ, in addition to, or in the place of, what it had before. Not only, then, is the doctrine of the transmutation of species in itself disproved by the best physiological reasonings, but the additional assumptions which are requisite, to enable its advocates to apply it to the explanation of the geological and other phenomena...
Página 116 - ... applied to homologous series of organic compounds; the relation between constitution and color and other optical properties, etc. Along with this went naturally the question of the properties of a substance as affected by mixture with another, of solutions in particular. The fact that the boiling point of a solution is higher than that of the solvent itself had long been known, and measurements of the rise in boiling point caused by equal weights of dissolved material had been made; but it was...
Página 191 - ... but their existence, often in enormous quantities, in situations quite removed from large waters; inland, — in high banks, imbedded in strata, or scattered, occasionally, in profusion, on the face of almost every region, and sometimes on the tops and declivities of mountains, as well as in the valleys between them; their entire difference, in many cases, from the rocks in the country where they lie — rounded masses and pebbles of primitive rocks being deposited in secondary and alluvial regions,...
Página 215 - But anyone who is practically acquainted with scientific work is aware that those who refuse to go beyond fact rarely get as far as fact, and anyone who has studied the history of science knows that almost every great step therein has been made by the "anticipation of nature...
Página 191 - The almost universal existence of rolled pebbles, and boulders of rock, not only on the margin of the oceans, seas, lakes, and rivers ; but their existence, often in enormous quantities, in situations quite removed from large waters ; inland, — in high banks, imbedded in strata, or scattered, occasionally, in profusion, on the face of almost every region, and sometimes on the tops and declivities of mountains, as well as in the...

Información bibliográfica