"parts is parts"

         That architectural wonder "The Biological Structure" is held together by parts. Parts of this and, parts of that. These parts are called "elements". Now what are these you might ask. A whole table of elements exist under the title "Periodic Table Of The Elements". My learning curve to such wonders is held in my hand as this topic is presented. A scan of the cover follows - 

        Oh ... No! A "Chemistry" book? Not high on my all-time reading list. Anyhow, this 1966 edition has followed me through my corridors of learning along my way.  Inside the front cover this "periodic table" of the elements is shown. Some of these elements grasp hands and, once joined they form the architectural units of our cells. Now the properties recur periodically if the elements are arranged in certain order. This arrangement has come to be called the "Periodic Law"! Who would have guessed? 

Sienko, M.J., Plane, R.A., Chemistry: Principles and Properties, McGraw-Hill Book Company, N.Y., 1966.