The symbol is often not connected with the _idea_ but with the _word_.

The mode in which this is done corresponds precisely to that of the rebus.

It is a simple method, readily suggesting itself.

In the middle ages it was much in vogue in Europe for the same purpose for which it was chiefly employed in Mexico at the same time--the writing of proper names.

For example, the English family Bolton was known in heraldry by a _tun_ transfixed by a _bolt_.
Precisely so the Mexican emperor Ixcoatl is mentioned in the Aztec manuscripts under the figure of a serpent _coatl_, pierced by obsidian knives _ixtli_, and Moquauhzoma by a mouse-trap _montli_, an eagle _quauhtli_, a lancet _zo_, and a hand _maitl_.