NATURAL PHILOSOPHY. 



INTRODUCTION. 



Ural Philoso 

 phy? 



What is Nat- ^' Natural PHILOSOPHY, Or Physics, is that 

 department of science which treats of all those 

 phenomena observed in masses of matter, in 



which there is a sensible change of place. 



2. Chemistry, on the contrary, treats of all 

 c^e^st^yT those phenomena observed to take place in 



minute particles, or portions of matter, in which 

 there is a change in the character and composition of the 

 matter itself, and not merely a change of place. 



3. A falling body, the motion of our limbs 

 Miptes^ol-fhe ^^ °^ machinery, the flow of liquids, the occur- 

 Natu^rJ^'m- '■^^ce of sound, the changes occasioned by the 

 losophyf action of heat, light, and electricity, are all ex- 

 amples of phenomena which come under the 



consideration of Natural Philosophy. 



Strictly speaking, we have no right, in Natural Philosophy, to conceive or 

 imagine any thing, for the truths of all its laws and principles may be proved 

 by direct observation, — that is, by the use of our senses. When we conceive, 

 reason, or imagine concerning the properties of matter, we have in reality 

 passed beyond the limits of Natural Philosophy, and entered upon the applica- 

 tion of the laws of mind or of mathematics to the principles of Natural Philos- 

 ophy. Practically, however, no such division of the subject is ever made. 



The truths and operations of Chemistry, in contradistinction to the trutlis 

 and operations of Natural Philosophy, can not all be proved and made evident 

 by direct observation. Thus, when we unite two pieces of machinery, as two 

 wheels, or when we lift a weight with our hands, or move a heavy body by a 

 lever, we are enabled to see exactly how the different substances come in 



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