8o6 THE POPULAR SCIENCE MONTHLY. 



affair. Only about a thousand species are known, and one large 

 volume may fairly cover the field. It is when we consider the mineral 

 as a growth — as a body having a past and a future — that broad treat- 

 ment of the subject becomes possible. The geologist, dealing with 

 phenomena of the grandest character, sees at a first glance little that 

 is attractive in mineralogy. He forgets that mineral species make his 

 alphabet, and that upon their properties the properties of rock-masses 

 must depend. He can not safely generalize upon the one without 

 knowing something of the other. He can not understand the chemi- 

 cal changes occurring in the earth's crust, if he ignores the separate 

 units and the reactions of which they are capable. The very genesis 

 of many rocks must depend upon the conditions under which their 

 individual units can concurrently exist, and the latter must be known 

 before the larger question can be adequately handled. Mineralogy 

 gives to the geologist the weightiest of evidence. To the chemist also 

 it is something more than debtor. It gives him, ready made, whole 

 groups of compounds which else would be difiicultly attainable, and 

 these are the starting-points for many lines of research. The true 

 character of each science is best seen in the interaction of all the 

 sciences. Each in its way is both servant and master ; not one can 

 stand wholly alone. 



THE UNIFOEMITY OF SOCIAL PHE^'OMENA. 



By F. X. VON NEUMANN-SPALLAET. 



THE surprising consequences which have attended investigations 

 in natural science have excited among the representatives of 

 historical and speculative studies a desire to reach results of corre- 

 sponding value by the application of observation and analysis to the 

 affairs of life. In this manner has arisen a new school of historical 

 research, which applies the facts of physical geography, anthropol- 

 ogy, ethnography, and other related branches of science, to the ex- 

 planation of events, and by this means has passed from mechanical 

 transcription and compilation to the examination into the natural, 

 causal connection of things. In the same way, speculative philosophy 

 has happily become an inductive branch of investigation, and instead 

 of the " eloquent words" with which metaphysics used to labor, scien- 

 tific analysis satisfies the aspirations in that direction, and is reviving 

 with its refreshing breath the withered branches of the world's wis- 

 dom. It is not out of course, then, that the sciences of social life also 

 should try to discard the tinsel of empty words and to gain by scien- 

 tific methods a concrete understanding and a real view of their condi- 

 tions. The question has thus arisen, whether the endlessly comjilicated 

 and shifting events which are incessantly modifying the aspects of 

 human society can be followed up and explained by natural laws ; 



