306 PERSONAL PREPARATION FOR RESEARCH. 



CHAPTER XXXII. 



NECESSITY OF INVENTIVE-POWER. ADVANTAGE OF 

 EXPERIMENTS. 



A DISCOVERER is a tester of scientific ideas ; he must not 

 only be able to imagine likely hypotheses, and to select suit- 

 able ones for investigation, but, as hypotheses may be true 

 or untrue, he must also be competent to invent appro- 

 priate experiments for testing them, and to devise the 

 requisite apparatus and arrangements. 



Experiments and observations are the original sources 

 of new scientific knowledge. The chief use of experi- 

 ments is to enable us to test hypotheses and verify true 

 ones ; to expel error, increase the certainty of our know- 

 ledge, and extend the domain of scientific truth. As no 

 man can foretell with certainty, except in special cases, 

 the result of a new and untried experiment, trials and 

 observations must be made, in order to settle the ques- 

 tion, and wrong paths have often to be traversed before 

 we find the right one. From every experiment, however, 

 if carefully performed, some definite knowledge may be 

 obtained, provided its conditions are definite and known ; 

 and by means of a sufficient variety and number of experi- 

 ments we are enabled to answer a particular question, or 

 several questions, and thus to sweep away a large number 

 of alternate false hypotheses we had framed with it. 

 Leonardo da Vinci, prior to Lord Bacon, suggested that 

 the proper mode of discovering new scientific knowledge 

 was by means of experiment and observation. 



The most accurate conditions for observation are gene- 

 rally obtained by means of experiments, because we can 



