What Is Life? The Physical Aspect of the Living Cell is a 1944 science book written for the lay reader by physicist Erwin Schrödinger.

What Is Life? – Wikipedia

32-page version (lectures) http://www.whatislife.ie/downloads/What-is-Life.pdf

1944 book

http://herba.msu.ru/shipunov/school/univ_110/papers/schroedinger1944_what_is_life.pdf

or

http://strangebeautiful.com/other-texts/schrodinger-what-is-life-mind-matter-auto-sketches.pdf