ABSTRACT
The word ‘prescription’ is derived from the Latin and is a formula which lays down, in advance, rules or directions for the preparation and administration of the ingredients of a medical remedy. Nowadays medical prescriptions are simple in format because standard drug formulations were introduced into therapeutics during the twentieth century. As time went by the Eye of Horus became used as a practical shorthand to quantify the ingredients of a prescription. The udjat eye contained 64 parts and each area of the eye formed a fraction of the total. Each division could represent a proportional volume or fraction of the total ingredients. In conclusion, Paris, J. A. wrote that ‘the character which the readers at this day place at the head of our prescriptions, and which is understood, and supposed to mean recipe, is a product of the astrological symbol of Jupiter disguised by the addition of the down stroke, which converts it into the letter Rx.’.
