Til.] 



INDUCTION. 



127 



tions deductively from four laws of correction, but my 

 correspondents found that three simpler laws, equivalent 

 to the four more complex ones, were the best answer ; these 

 laws are as follows : a = ac, b = cd, d = E/. 



In case other readers should like to test their skill in the 

 inductive or inverse problem, I give below several series 

 of combinations forming problems of graduated difficulty. 



Induction of Simple Identities. 



I\Tany important laws of nature are expressible in the 

 form of simple identities, and I can at once adduce them 

 as examples to illustrate what I have said of the difficulty 

 of the inverse process of induction. Two phenomena are 

 conjoined. Thus all gravitating matter is exactly co- 

 incident witli all matter possessing inertia ; where one 



