Turn away when spitting lest your saliva fall on someone. If anything purulent falls on the ground, it should be trodden upon, lest it nauseate someone.
To lick greasy fingers or to wipe them on your coat is impolite. It is better to use a tablecloth or the serviette.
Some people put their hands in the dishes the moment they sat down. Wolves do that.
You should not offer your hankerchief to anyone unless it is freshly washed. Nor is it seemly, after wiping your nose, to spread out your hankerchief and peer into it as if pearls and rubies might have fallen out of your head.
Do not be afraid of vomiting, if you must; for it is not the vomiting but holding the vomit in your throat that is foul.
If you cannot swallow a piece of food, turn around and discreetly throw it somewhere.
Do not move back and forth in your chair. Whoever does that gives the impression of constantly breaking wind or trying to break wind.
Retain the wind by compressing the belly.
Erasmus (c.1530)