388 THE LAW OF EVOLUTION CONTINUED. 



the nature of the relation between a and &, nor how much of 

 a accompanied so much of b. The development of Science 

 has in part been the reduction of these vague connexions to 

 distinct ones. Most relations have been classed as me- 

 chanical, chemical, thermal, electric, magnetic, &c. ; and we 

 have learnt to infer the amounts of the antecedents and con- 

 sequents from each other with exactness. Of 

 illustrations, some furnished by physics have been given; 

 and from other sciences plenty may be added. We have 

 positively ascertained the constituents of numerous com- 

 pounds which our ancestors could not analyze, and of a far 

 greater number which they never even saw; and the com- 

 bining equivalents of these elements are accurately calcu- 

 lated. Physiology shows advance from qualitative to quan- 

 titative prevision in the weighing and measuring of organic 

 products, and of the materials consumed; as well as in 

 measurement of functions by the spirometer and the sphyg- 

 mograph. By Pathology it is displayed in the use of the 

 statistical method of determining the sources of diseases, 

 and the effects of treatment. In Botany and Zoology, the 

 numerical comparisons of Floras and Faunas, leading to 

 specific conclusions respecting their sources and distribu- 

 tions, illustrate it. And in Sociology, questionable as are 

 the conclusions usually drawn from the classified sum-totals 

 of the census, from Board-of -Trade tables, and "from crimi- 

 nal returns, it must be admitted that these imply a progress 

 towards more accurate conceptions of social phenomena. 



That an essential characteristic of advancing Science is 

 increase in definiteness, appears indeed almost a truism, 

 when we remember that Science may be described as definite 

 knowledge, in contradistinction to that indefinite knowledge 

 possessed by the uncultured. And if, as we cannot question, 

 Science has, in the course of ages, been evolved out of this 

 indefinite knowledge of the uncultured; then, the gradual 

 acquirement of that great definiteness which now distin- 

 guishes it, must have been a leading trait in its evolution. 



