SCIENCE.] INTRODUCTORY. 9 



Artificial things are, in fact, all produced by the 

 action of that part of nature which we call mankind, 

 upon the rest. 



We talk of "making " a box, and rightly enough, if 

 we mean only that we have shaped the pieces of wood 

 and nailed them together ; but the wood is a natural 

 object and so is the iron of the nails. A watch is 

 " made " of the natural objects gold and other metals, 

 sand, soda, rubies, brought together, and shaped in 

 various ways ; a coat is " made " of the natural object, 

 wool ; and a frock of the natural objects, cotton or 

 silk. Moreover, the men who make all these things 

 are natural objects. 



Carpenters, builders, shoemakers, and all other 

 artisans and artists, are persons who have learned so 

 much of the powers and properties of certain natural 

 objects, and of the chain of causes and effects in 

 nature, as enables them to shape and put together those 

 natural objects, so as to make them useful to man. 



A carpenter could not, as we say, " make " a chair 

 unless he knew something of the properties and 

 powers of wood ; a blacksmith could not " make " a 

 horseshoe unless he knew that it is a property of iron 

 to become soft and easily hammered into shape when 

 it is made red-hot; a brickmaker must know many of 

 the properties of clay ; and a plumber could not do 

 his work unless he knew that lead has the properties 

 of softness and flexibility, and that a moderate heat 

 causes it to melt. 



So that the practice of every art implies a certain 

 knowledge of natural causes and effects; and the 

 improvement of the arts depends upon our learning 

 more and more of the properties and powers of natural 



