I came across an image of a vintage transferware mug that really caught my eye. I couldn't save a picture so do follow the links and see how wonderful it is. On it was imprinted a sentiment that appears to come from Franklin. Sometimes listed as Flowers that Never Fade, it reads:
Good humor is the greatest charm
That children can possess,
It makes them happy and what's more,
It gives them power to bless.
The Blue China Book gives a little background. It is "an expression of one of Franklin's favorite theories, one which he himself was in the habit of practicing - that good humor is one of Nature's flowers of character most powerful in its influence upon men."