Emungi

A naribus absit mucoris purulentia, quod est sordidorum. id quoque vitium Socrati philosopho datum est probro. pileo aut veste emungi, rusticanum; brachio cubitove, salsamentariorum; nec multo civilius id manu fieri, si mox pituitam vesti illinas. strophiolis excipere narium recrementa decorum, idque paulisper averso corpore, si qui adsint honoratiores. si quid in solum deiectum est, emuncto duobus digitis naso, mox pede proterendum est. indecorum est subinde cum sonitu spirare naribus: bilis id indicium est. turpius etiam ducere ronchos, quod est furiosorum, si modo fiat usu. nam spiritosis qui laborant orthopnoea danda est venia. ridiculum, vocem naribus emittere: nam id cornicinum est et elephantorum. crispare nasum irrisorum est et sanniorum. si aliis praesentibus incidat sternutatio, civile est corpus avertere; mox ubi se remiserit impetus, signare os crucis imagine; item sublato pileo resalutatis qui vel salutarunt, vel salutare debuerant (nam sternutatio, quemadmodum oscitatio, sensum aurium prorsus aufert), precari veniam, aut agere gratias. alterum in sternutamento salutare, religiosum: et si plures adsunt natu maiores qui salutant virum aut feminam honorabilem, pueri est aperire caput. porro vocis tinnitum studio intendere, aut data opera sternutamentum iterare, nimirum ad virium ostentationem, nugonum est. reprimere sonitum quem natura fert, ineptorum est, qui plus tribuunt civilitati quam saluti.
(Erasmus, De Civilitate Morum Puerilium 5)

The nostrils should be free from any filthy collection of mucus, as this is disgusting (the philosopher Socrates was reproached for that failing too). It is boorish to wipe one’s nose on one’s cap or clothing; to do so on one’s sleeve or forearm is for fishmongers and it is not much better to wipe it with one’s hand, if you then smear the discharge on your clothing. The polite way is to catch the matter from the nose in a handkerchief, and this should be done by turning away slightly if decent people are present. If, in clearing your nose with two fingers, some matter falls on the ground, it should be immediately ground under foot. It is bad manners to breathe noisily all the time, which is the sign of furious anger. It is even worse to make a habit of snorting like one possessed, although we must make allowance for heavy breathers who are afflicted with asthma. It is ridiculous to trumpet with one’s nose; this is for horn-blowers and elephants. Twitching the nose is for scoffers and buffoons. If you must sneeze while others are present, it is polite to turn away. When the attack has subsided you should cross your face, then, raising your cap and acknowledging the blessings of those who have (or you assume to have) blessed you (for sneezing, like yawning, completely mocks one’s sense of hearing), beg pardon or give thanks. One should be scrupulous in blessing another when he sneezes. If older people are present and bless a high-ranking man or woman, the polite thing for a boy to do is to raise his cap. Again, to imitate or consciously repeat a sneeze—in effect to show off one’s strength—is the sign of a fool. To suppress a sound which is brought on by nature is characteristic of silly people who set more store by ‘good manners’ than good health. (tr. Brian McGregor)