I make a living selling dehydrated body fluids, especially blood, yellow bile, black bile and phlegm.
I'm well renouned for my dry humors.
Hippocrates and the Prophet
Tiresias, blind prophet of Apollo, once went to Hippocrates with a serious case of depression. In no time, Hippocrates had figured it out -- "Aha!" said he; "an imbalance of black bile!" He bled the excess melancholia into an urn and handed it to the prophet. Tiresias did not see the humour.