THE UNITY OF SCIENCE 6 



the outward conditions of human life that were to come 

 through applied science were as yet only the vague dreams of 

 the leisure moments of a busy and corrupt lawyer. By the 

 late eighteenth century several new sciences were passing 

 through the distempers of childhood — chemistry, dynamic 

 geology, the theory of electricity, physical anthropolog>% for 

 example; political economy was emerging somewhat abruptly 

 into a truly scientific form ; an ostensibly novel and revolu- 

 tionary way of attacking the problems of philosophy seemed 

 to promise a final consummation of that age-long endeavor; 

 the evolutionary way of thinking about the past and present 

 of mankind was beginning to come into vogue ; and mean- 

 while men's minds were full of eager hopes for the 'perfect- 

 ing' of human nature and of society. But, save in the hands 

 of a few men ahead of their time, zoology and botany were 

 still little more than descriptive "natural history" ; and the 

 really fruitful methods and basic principles of both chemistry 

 and physics were still to be discovered. 



Throughout the nineteenth century, it is true, nearly all 

 of the sciences developed continuously and rapidly; but they 

 did not progress with even pace. The notable crises that 

 mark the scientific movement of the last century, the periods 

 of radical innovations and fundamental reconstructions, were 

 — if you will recall the dates — often separated by consider- 

 able intervals. The establishment of the true working-prin- 

 ciples of chemistry, the achievement of Dalton, Gay-Lussac 

 and Avogadro, came in the first decade of that century. The 

 great extensions of the theory of functions, and the new 

 geometry, came in the third. A little later Lyell gave to 

 modern geology its accepted method. It was not until the 

 middle of the eighteen-forties that physics found its funda- 

 mental principle, that of the conservation of energ}^ ; this was 

 speedily followed by the discovery of the complementary law 

 of the degradation of energy and the resultant birth of the 

 theoretically most important child of modern physics, the 

 science of thermodynamics. It was a full decade later that 



