SCIENCE.] INTRODUCTORY. 19 



perfected common sense. Scientific reasoning is 

 simply very careful common reasoning, and common 

 knowledge grows into scientific knowledge as. it be- 

 comes more and more exact and complete. 



The way to science then lies through common know- 

 ledge ; we must extend that knowledge by careful obr 

 servation and experiment, and learn how to state the 

 results of our investigations accurately, in general 

 rules or laws of nature ; finally, we must learn how 

 to reason accurately from these rules, and thus arrive 

 at rational explanations of natural phenomena, which 

 may suffice for our guidance in life. 



II. MATERIAL OBJECTS. A. MINERAL BODIES. 



12. The Natural Object Water. 



One of the commonest of common natural objects 

 is water ; everybody uses it in one way or another 

 every day ; and consequently everybody possesses a 

 store of loose information of common knowledge 

 about it. But, in all probability, a great deal of this 

 knowledge has never been attended to by its pos- 

 sessor ; and certainly, those who have never tried to 

 learn how much may be known about water, will be 

 ignorant of a great many of its powers and properties 

 and of the laws of nature which it illustrates; and 

 consequently will be unable to account for many 

 things of which the explanation is very easy. So 

 we may as well make a beginning of science by 

 studying water. 



