44 DISCOURSE ON THE STUDY 



What pains and expense would not the alchemists, 

 for instance, have been spared by a knowledge of 

 those simple laws of composition and decomposition, 

 which now preclude all idea of the attainment of 

 their declared object ! what an amount of ingenuity, 

 thrown away on the pursuit of the perpetual motion, 

 might have been turned to better use, if the simplest 

 laws of mechanics had been known and attended 

 to by the inventors of innumerable contrivances 

 destined to that end ! What tortures, inflicted on 

 patients by imaginary cures of incurable diseases, 

 might have been dispensed with, had a few simple 

 principles of physiology been earlier recognised ! 



(35.) But if the laws of nature, on the one hand, 

 are invincible opponents, on the other, they are 

 irresistible auxiliaries ; and it will not be amiss if 

 we regard them. in each of those characters, and con- 

 sider the great importance of a knowledge of them 

 to mankind, 



I. In showing us how to avoid attempting im- 

 possibilities. 



II. In securing us from important mistakes in at- 

 tempting what is, in itself, possible, by means 

 either inadequate, or actually opposed, to the 

 end in view. 



III. In enabling us to accomplish our ends in the 



easiest, shortest, most economical, and most 

 effectual manner. 



IV. In inducing us to attempt, and enabling us to 



accomplish, objects which, but for such know- 

 ledge, we should never have thought of under- 

 taking. 



