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."