"No Man is richer for having his Estate all in Money, Plate, etc. lying by him, but on the contrary, he is for that reason the poorer"

This quote by Dudley North is stressing the value of investing and using one's wealth. North is recommending that having all of one's wealth in the kind of cash, plate, and so on is not helpful and does not make one richer. Rather, North is recommending that having one's wealth bought other kinds, such as stocks, bonds, and real estate, is the very best method to increase one's wealth. North is suggesting that having one's wealth in the type of money, plate, etc is not a wise decision since it does not create any additional income or increase in value. North is suggesting that investing one's wealth in other kinds is the very best method to increase one's wealth and become richer. North is stressing the importance of utilizing one's wealth in order to end up being richer, instead of merely having it sit idle.