Leaves are folded together to bind them and to make them easy to handle. This image shows a set of 4 leaves folded together, the red one innermost.
The Latin word quaterni meaning 'a set of 4' came into Old French as quaier which by our period of Middle French in the early 1400s had shifted to cahier. It is the source of the Middle English word, quire.
Cahier and quire have become well used but have lost their precise meaning of 4. Codicology has a more precise word for this gathering of 4, quaternion.
Please keep copying your answers into your own electronic notes file
f2v Click to next page (pto)