398 THE POPULAR SCIENCE MONTHLY. 



make less distinct the lines that separate the three kingdoms from one 

 another, so that we are led to the conclusion that the mineral kingdom 

 is connected by successive degrees with the vegetable and animal 

 kingdoms, and consequently that matter is one. 



Hence the study of mineralogy, giving the word its real significa- 

 tion of a science applying to all unorganized bodies, ought to precede 

 the study of botany and zoology, because it is the rational introduc- 

 tion to knowledge respecting the phenomena of Nature. There is 

 manifest in these days an evolution from the sciences called natural 

 toward the physical and chemical sciences, and from the physical and 

 chemical sciences toward the mathematical sciences. 



A natural phenomenon is the resultant of multiple actions which 

 make themselves perceived concurrently in its manifestation. It is 

 an equation containing many unknown quantities. There is only one 

 way to resolve it : it is to find a sufiicient number of other equations 

 containing the same unknown quantities with different coefficients 

 and exponents, and then to eliminate the unknown elements one after 

 the other. That is the object of experiments, in which man inter- 

 venes with his intelligence and his hands to simplify and finally to 

 resolve the problem that he proposes to himself, which is to obtain a 

 complete knowledge of the phenomenon. In every experiment he 

 retains as constants some conditions which he can not wholly get rid 

 of, and limits himself to putting a single variable through its changes. 

 He then makes constant the variable, of which he has just examined 

 the influence, and subjects to modifications one of the other variables 

 which he had previously held as a constant. This work is really the 

 same as to formulate a new equation between different unknown quan- 

 tities. Every science must therefore rest upon experiment, which 

 alone is capable of leading to the knowledge of the law that is, to a 

 generalization, and of permitting the student to foresee results. A 

 science which can not generalize or foresee only deserves the name of 

 simple knowledge. Detailed observation translated into minute de- 

 scription is the servant of experimentation, for its task is limited to 

 verification. 



The science of inorganic bodies, mineralogy and geology, has been 

 the first to feel the effects of the evolution of the natural sciences 

 toward the exact physical and chemical sciences. Its phenomena pre- 

 sent the minimum of complication ; it ought, even more than the 

 others, if that is possible, to be founded on experiment, measure, fig- 

 ures, and number. 



I have been gratified to find my views on these subjects corrobo- 

 rated by the observations of Professor Mario Pilo, of the Lyceo Balbo 

 in Turin, as recorded in a paper published by him in the " Ri vista di 

 filosofia scientifica," on " The Life of Crystals ; or, Outlines for a 

 Future Mineral Biology." This author has collected a large number 

 of results agreeing with the doctrine of the successive and insensible 



