Science Quote by Dmitri Mendeleev

A quiet act of rebellion hides in Mendeleev's careful phrasing: chemistry should not be a scrapbook of anecdotes, but a system with rules. In the mid-19th century, “atomic weight” was one of the few hard numbers chemists could trust across laboratories, even as the deeper structure of the atom was still a black box. Mendeleev leverages that shaky-but-shared metric like a political organizer uses a coalition: not perfect, but strong enough to impose order.

The sentence reads modestly - “either…or,” a couple of parenthetical examples - yet its ambition is sweeping. He’s arguing that similarity in chemical behavior is not a poetic resemblance but a measurable recurrence. The subtext is methodological: if properties repeat in a regular way, then chemistry can predict, not just catalog. That’s the hinge on which the periodic table swings from classification to prophecy.

Notice how he offers two patterns, not one. “Nearly the same value” (Pt, Ir, Os) covers clusters where weights bunch up, while “increase regularly” (K, Rb, Cs - his intended family) captures a stepwise march. That flexibility is strategic; he’s describing periodicity as a principle that survives messy data. In an era of disputed atomic weights and misassigned elements, Mendeleev is building a framework that can absorb exceptions without collapsing.

The deeper context is competitive: multiple scientists were circling periodic classification. Mendeleev’s edge wasn’t just arranging known elements; it was making the regularity sound inevitable, like nature had been waiting for someone to notice the beat.