6. To read Dioscorides, to learn ye nature of plants and herbes. (Dioscorides published a work on vegetable remedies about 1499, in Greek. The _translation_ was referred to.) 8. To have his morters, stilles, pottes, filters, glasses, and boxes cleane and sweete. 12. That he neither increase nor diminish the physician's bill (prescription), nor keepe it for his own use.