10 



INTRODUCTION. 



sents itself: whether general views of nature 

 can be brought to anything like precision with- 

 out deep and earnest study of the several de- 

 partments of natural science — natural history, 

 natural philosophy, and physical astronomy] 

 Here it is proper to distinguish carefully be- 

 twixt the teacher, who makes selections and 

 delivers an account of results, and the pupil, 

 who receives the account as something pre- 

 sented to him not investigated for himself. For 

 the former, the most intimate knowledge of 

 specialities is indispensably necessary ; he must 

 have long familiarised his mind with the several 

 sciences, he must himself have taken the 

 length and the breadth of things, observed and 

 made experiments, before he can, with any 

 confidence or, propriety, venture on a picture of 

 nature as a whole. The entire bearings of the 

 problems whose investigation lends such attrac- 

 tions to the physical history of the world are 

 perhaps scarcely to be comprehended in all 

 their clearness where special preliminary knowl- 

 edge is wanting; although, without it, the 

 greater number of the propositions can still be 

 satisfactorily discussed. If the great picture 

 of nature be not presented with its outlines 

 equally clear and sharp in every part, it will 

 still be found sufficiently true and attractive to 

 enrich the mind with ideas, and to arouse and 

 fructify the imagination. 



It has been made matter of reproach — and 

 perhaps with some propriety — that the scien- 

 tific works in our language do not sufficiently 

 separate the General from the Particular — the 

 review of actually established facts from the 

 narrative of the means by which the results 

 have been obtained. This imputation has led 

 the greatest poet of our age(") humorously to 

 say, that " the Germans possess the faculty of 

 making the sciences inaccessible." But the 

 scaffold left standing, we are hindered from ob- 

 taining a clear view of the building. And who 

 will doubt, that the physical law in the distri- 

 bution of the continental masses, which assume 

 a pyramidal shape towards the south, whilst 

 towards the north they spread out into vast 

 bases — a law by which the division of climates, 

 the prevalence of particular winds, the extension 

 of tropical vegetable forms into the temperate 

 northern zones, is explained in the most satis- 

 factory manner — can be understood without 

 reference to the trigonometrical surveys, and 

 the astronomical determinations of precise ge- 

 ographical positions, by which the dimensions 

 of the pyramids referred to have been ascer- 

 tained 1 In the same way, we learn from phys- 

 ical geography, that the equatorial axis of our 

 planet is greater than the polar axis by a cer- 

 tain number of miles, that the southern hemi- 

 sphere is not flattened in a greater degree than 

 the northern hemisphere, &c., without its be- 

 ing necessary to narrate at length how, by 

 measurements of degrees of the meridian, and 

 experiments with the pendulum, the figure of 

 the earth has been finally determined to be that 

 of an irregular spheroid of revolution in an el- 

 lipsis ; and how this figure is reflected in the 

 motions of our satellite, the moon. 



Our neighbours on the other side of the Rhine 

 possess an immortal work, Laplace's " Sys- 

 teme du Monde," in which the results of the 

 most profound mathematico- astronomical in- 



vestigations of the phenomena of past centunes 

 are luminously presented, freed from the indi- 

 vidualities of the demonstration. The struc- 

 ture of the heavens there j)resents itself as the 

 simple solution of a great problem in mechan- 

 ics. Yet no one has ventured to charge the 

 " Exposition du Systeme du Monde" with want 

 of depth, because of its form. The separation 

 of the Dissimilar in views, of the General from 

 the Special, is not merely useful in facilitating 

 the acquisition of knowledge ; it farther gives 

 an elevated and earnest character to the treat- 

 nient of natural science. As from a higher sta- 

 tion we overlook larger masses at once, so are 

 we pleased mentally to grasp what threatens 

 to e%cape the powers of our senses. If the 

 successful cultivation of every branch of natu- 

 ral science in recent times, appear especially 

 calculated to extend the study of particular de- 

 partnrients — the chemical, the physical, the phys- 

 iological, &c. — the progress made in each will 

 nevertheless contribute in an eminent degree 

 to abridge and render 'easy the way to the at- 

 tainment of general principles. 



The more deeply we penetrate into the es- 

 sence of the natural forces, the more do we 

 perceive the connection of phenomena, which, 

 severally and superficially regarded, seemed 

 long to resist every attempt at co-ordination 

 and arrangement ; the more do we see simpli- 

 city and brevity possible. 



It is a certain indication of the extent and 

 value of the discoveries which were to be look- 

 ed for in any science, when the facts present 

 themselves as still unconnected, almost, as it 

 seems, without any thing like mutual reference, 

 and when several of them, the fruit of the same 

 degree of careful observation, even appear con- 

 tradictory or subversive. We stand at this* 

 time in a state of lively expectation in regard 

 to meteorology, to some of the departments of 

 optics, and especially, since Melloni and Fara- 

 day came upon the stage, to the radiation of 

 heat and electro-magnetism. The field of brill- 

 iant discovery here, has certainly not yet been 

 exhausted, although a very remarkable con- 

 nection of electrical, magnetical, and chemical 

 phenomena has undoubtedly been developed in 

 the voltaic pile. And who shall guarantee us 

 that the entire number of the vital forces effi- 

 cient in the universe has been fathomed 1 



In my mode of considering the scientific treat- 

 ment of a general description of creation, I 

 make no question of that unity which is arrived 

 at by induction from a few fundamental princi- 

 ples supplied by reason. What I entitle a Phys- 

 ical History of Creation — in other words, a 

 comparative natural history of the earth and 

 heavens — consequently, makes no pretensions 

 to the rank of a rational. Science of Nature ; 

 it is a simple consideration of the phenomena 

 that are known empirically, or by experience, 

 as a natural whole. With the entirely object- 

 ive constitution of my mind, it is under such 

 restrictions alone that the history of creation 

 falls within the scope of the inquiries which 

 have exclusively occupied me in the long course 

 of my scientific life. I do not venture upon a 

 field that is strange to me, and that will prob- 

 ably be cultivated to better purpose by another. 

 The unity attainable in such a history of crea- 

 tion as I propose to exhibit, is no more thaa 



