284 NATURAL HISTORY OF ORGANIZED BODIES. 



rior discoveries respecting the functions of animals and plants. Nor yet is tlie 

 actual tendency, as it seems, to descriptive studies. At tlie point wbicli anatomy 

 Las reached, what is rather to be apprehended is confusion, through the midti- 

 plicity of minute details. Our science is already encumbered with descriptions 

 which the life of one man would not suffice to master. 



To this it may be answered that it is precisely to remedy this obstniction that 

 recourse is had to a division of labor; that, by virtue of this expedient, we may 

 Icjok with confidence to the indefinite increase of human science, each ramifica- 

 tion of which will be developed l»y the assiduity of inquirers devoted exclusively 

 to some speciality. But can it be necessary to show how much such a state of 

 tilings is to l)e deprecated ? The more thoroughly any point of science is inves- 

 tigated the more numerous and intimate are found to be its connections with all 

 others. Need we recall the services which zoology and botany have rendered 

 to geology, the utility of chemistry and physics to those who cultivate anatomy 

 or pln'siologj'? So much for the solidarity, the inter-dependence of the sciences, 

 in view of the means of study and the furtherance of one through the other; 

 a lilic solidarity is found in regard to the laws which govern them. 



Every law, when once known, throAVS light on a vast field, for it controls a 

 great nund)er of phenomena. The law of proportionality to the squares applies 

 not only to the gravitation of the heavenly bodies, but to light, electricity, mag- 

 netic attraction, accelerated movement, &:c. Chemical laws enable ns to foresee 

 a great number of phenomena which no one has yet attempted to realize. 



If all the sciences allowed of our evolving, from this time forward, precise 

 laws, it would be easy for us to combine in a grand assemblage all dispersed 

 facts; a single mind might embrace in their generality all human cognitions; 

 what the sages of antiquit}^ could not realize l)y reason of the narrow extent of 

 their knowledge, would be accomplished to-day on a field much more vast, 

 thanks to the excellence and simplicity of method. This ideal, which however 

 we shall never attain, should at least be the star which serves us for a guide ; 

 it is to the research of the laws of life that it behooves us henceforth to direct 

 our earnest attention. 



II. — Office of ais^alysis in the sciences. — power "which it derives 



FROM THE EMPLOYMENT OF GREATLY IMPROVED INSTRUilENTS. 



I have endeavored to show that the human mind proceeds in all the sciences 

 after nearly the same manner, so that, as regards each of them, progress is rep- 

 resented by an evolution strikingly similar. I hope to prove also that the 

 sciences, in the process of their development, tend to an approximation towards 

 one another, resulting in their reciprocal advancement, since each of them sheds 

 light upon the other. Zoology and botany, it is obvious, have ftmiished to 

 geology an inestimable element of progress, by disclosing one of the most indis- 

 pensable characters for recognizing tlie relative age of different formations. This 

 character is derived from the determination of fossil species, some of which 

 characterize, so to speak, certain geological epochs. 



Physics and chemistry have so many points of contact that it is almost 

 superfluous to mention them; the time may be foreseen when these two 

 sciences can be no longer separated, chemistry constituting, in effect, only 

 molecular physics. But physics and chemistry exert on the other hand an ever- 

 increasing influence on the natural sciences. Neither animal nor vegetable 

 physiology can dispense with their aid; it may even be said that all that we 

 know accurately in these two sciences is what is explained by means of the 

 laws of physics and chemistry. Examjiles would present themselves in crowds 

 W'ere it requisite to furnish them. Thus the mechanical phenomena of respira- 

 tion were unintelligible before atmospheric pressure had been discovered. Anato- 

 mists and physiologists were sui'prised to see the air rush into the plem'a when 



