Consider: This Quote on the Periodic Law:

Dmitry Mandeleev, the Russian Chemist who discovered the periodic law, said in a lecture in 1889:

"Before the promulgation of the periodic law the chemical elements were mere fragmentary incidental facts in nature; there was no special reason to expect the discovery of new elements, and the new ones which were discovered from time to time appeared to be possessed of quite novel properties. The law of periodicity first enabled us to perceive undiscovered elements at a distance which formerly were inaccessible to chemical vision, and long ere they were discovered new elements appeared before our eyes possessed of a number of well-defined properties."

It is asked to think of these quote in a scientific context.

A Reflection Post

An initial postreflecting on the quoteabove. The reflection should be based on the knowledge of the periodic law; the reflection should be scientific in nature and not purely philosophical.