4 i8 THE POPULAR SCIENCE MONTHLY. 



sun, so that, if the principal portion of the solar mass were either solid 

 or liquid, its mean density ought to be at least as great as the earth's, 

 especially since the enormous force of solar gravity would tend most 

 powerfully to compress the materials. The low density can only he 

 accounted for on the supposition, which seems fairly to accord also 

 with all other facts, that the sun is mainly a ball of gas, or vapor, 

 powerfully condensed, of course, in the central portion by the super- 

 incumbent weight, but prevented from liquefaction by an exceed- 

 ly high temperature. And, on the other hand, it could be safely pre- 

 dicted on physical principles that so huge a ball of fiery vapor, ex- 

 posed to the cold of space, would present precisely such phenomena 

 as we find by observation of the solar surface and surroundings. 



-- 



EDUCATION AS A SCIENCE. 



By ALEXANDER BAIN, LL.D., 



PROFESSOR IN THE UNIVERSITY OF ABERDEEN. 

 I. 



THE scientific treatment of any art consists partly in applying the 

 principles furnished by the several sciences involved as chemi- 

 cal laws to agriculture and partly in enforcing, throughout the dis- 

 cussion, the utmost precision and rigor in the statement, deduction 

 and proof of the various maxims or rules that make up the art. 



Both fecundity in the thoughts and clearness in the directions 

 should attest the worth of the scientific method. 



Definitions of the Scope of Education. First, let me quote the 

 definition embodied in the ideal of the founders of the Prussian Na- 

 tional System. It is given shoi'tly as "the harmonious and equable 

 evolution of the human powers;" at more length, in the words of 

 Stein, " by a method based on the nature of the mind, every power of 

 the soul to be unfolded, every crude principle of life stirred up and 

 nourished, all one-sided culture avoided, and the impulses on which 

 the strength and worth of men rest carefully attended to." (Donald- 

 son's " Lectures on Education," p. 38.) This definition, which is pointed 

 against narrowness generally, may have had special reference to the 

 many omissions in the schooling of the foregone times: the leaving 

 out of such things as bodily or muscular training ; training in the 

 senses or observation ; training in art or refinement. It further in- 

 sinuates that hitherto the professed teacher may not have done much 

 even for the intellect, for the higher moral training, nor for the train- 

 ing with a view to happiness or enjoyment. 



Acting on this ideal, not only would the educator put more press- 



