Mr. Sumner is fond of alluding to his long Senatorial experience. Well, there are two kinds of lessons which may he learnt by expe rience. The one is most commonly expressed by the proverb that experience makes fools wise. But experience has also another teach ing. It has its evil a> well as its good side ;it tends not only to eradicate errors, but in some oases to confirm and make them inveterate.