He who will live longlet him be early with the morning-meal and not late with the evening-meal；let him be sparing of commerce with women and chary of cupping and blood-letting and make of his belly three partsone for foodone for drink and the third for air；for that a man's intestines are eighteen spans in length and it befits that he appoint six for foodsix for drinkand six for air. If he walklet him go gently；it will be wholesomer for him and better for his body and more in accordance with the saying of God the Most High'Walk not boisterously [or proudly] upon the earth.'（Q.）'What are the symptoms of yellow bile and what is to be feared there-from？'（A.）'The symptoms are，sallow complexion and dryness and bitter taste in the mouth，failure of the appetiteand rapid pulse；and the patient has to fear high fever and delirium and prickly heat and jaundice and tumour and ulceration of the bowels and excessive thirst.'
（Q.）'What are the symptoms of black bile and what has the patient to fear from itif it get the mastery of the body？'
（A.）'The symptoms are deceptive appetite and great mental disquiet and care and anxiety；and it behoves that it be evacuatedelse it will generate melancholy and leprosy and cancer and disease of the spleen and ulceration of the bowels.'
（Q.）'Into how many branches is the art of medicine divided？'
（A.）'Into two： the art of diagnosing diseases and that of restoring the diseased body to health.'（Q.）'When is the drinking of medicine more efficacious than otherwhen？'（A.）
'When the sap runs in the wood and the grape thickens in the cluster and the auspicious planets are in the ascendantthen comes in the season of the efficacy of drinking medicine and the doing away of disease.'（Q.）'What time is it，whenif a man drink from a new vesselthe drink is wholesomer and more digestible to him than at another timeand there ascends to him a pleasant and penetrating fragrance？'（A.）
'When he waits awhile after eatingas quoth the poet：
I rede thee drink not after food in hastebut tarry still；