ch. viii.] ORGANIZATION OF THE SCIENCES. 225 



constitution of the various tissues and anatomical elements, 

 and had furnished the means of explaining synthetically 

 such organic processes as digestion and assimilation. But, 

 as we have already seen, the obligation has not been all on 

 one side. The services rendered by the analytic to the syn- 

 thetic sciences have been all along repaid by services no less 

 essential. Thus the great principle of molar physics — the 

 law of gravitation — could not be generalized from terrestrial 

 phenomena alone, but had to wait until astronomic observa- 

 tions had revealed the true forms of the planetary orbits and 

 the rates of their velocities. Thus molecular physics has 

 received important hints from mineralogy, the properties of 

 crystals having rendered indispensable aid in the discoveries 

 of polarization and double refraction, and therefore in the final 

 verification of the undulatory theory. And thus also in late 

 years the researches of Dumas, Laurent, Gerhardt, and Wil- 

 liamson on the structure of organic molecules have reacted 

 upon the whole domain of inorganic chemistry, regenerating 

 the doctrine of types, supplying the fundamental conceptions 

 of atomicity and quantivalence, replacing the dualistic theory 

 of Berzelius by the theory of saturation and substitution, and 

 inaugurating a radical revolution in chemical nomenclature. 

 I may note in passing that this great revolution, which has 

 rendered the science of only half-a-generation ago com- 

 pletely antiquated, and has obliged so many of us to unlearn 

 the chemistry which we learned at college, furnishes a crucial 

 disproof of the Comtean theory of the way in which a 

 scientific revolution should occur. We see that the chemistry 

 of inorganic bodies was not placed upon its true foundation 

 until the study of organic chemistry had supplied to the 

 whole science its fundamental principles ; in spite of Comte, 

 who always scouted at organic chemistry as an illegitimate 

 science, and predicted the speedy extension of the dualistic 

 theory to organic compounda 



Space permitting, I might go on and point out more 



VOL. I. Q 



