There were many early ways of visually conveying information. Among the best studied is the system of tokens used to represent the contents of sealed containers in ancient Mesopotamia. The types and quanity of tokens stored in a pouch attached to the neck of a jar would identify the quantity of oil or grain inside the jar, without having to undeal the wax and increase the possibility of spoilage. Cuneiform writing, it is hypothesized, originally consisted of representation of the tokens on clay tablets and slowly evolved into a system that was part syllabary and part pictographs. Egyptian and Chinese ideographic writing originated independently in the same period -- roughly 3,000 BC.