THE POWER OF CHEMISTRY : STD 11TH AND 12TH COLLEGE

As a physical object a book is a stack of usually rectangular pages (made of papyrus parchment vellum or paper) oriented with one edge tied sewn or otherwise fixed together and then bound to the flexible spine of a protective cover of heavier relatively inflexible material.[1] The technical term for this physical arrangement is codex (in the plural codices). In the history of hand-held physical supports for extended written compositions or records the codex replaces its immediate predecessor the scroll. A single sheet in a codex is a leaf and each side of a leaf is a page. As an intellectual object a book is prototypically a composition of such great length that it takes a considerable investment of time to compose and a still considerable though not so extensive investment of time to read. This sense of book has a restricted and an unrestricted sense. In the restricted sense a book is a self-sufficient section or part of a longer composition a usage that reflects the fact that in antiquity long works had to be written on several scrolls and each scroll had to be identified by the book it contained. So for instance each part of Aristotles Physics is called a book as of course the Bible encompasses many different books. In the unrestricted sense a book is the compositional whole of which such sections whether called books or chapters or parts are parts. The intellectual content in a physical book need not be a composition nor even be called a book