Periodic table

Mendeleev dates and submits his first periodic-system manuscript

When his system was announced to fellow chemists, Mendeleev was away on an assignment inspecting cheese dairies.

A sheet dated 17 February 1869

Dmitri Mendeleev completed a manuscript titled “An Attempt at a System of the Elements Based on Their Atomic Weight and Chemical Affinity” and sent it for typesetting on 17 February 1869 in Russia's Julian calendar — 1 March in the Gregorian.

The sheet carried that Old Style date and handwritten instructions for the printer. He had been struggling to classify the 63 known elements consistently while writing Principles of Chemistry, comparing atomic weights, valences and chemical similarities — including by writing each element on a separate card and rearranging them.

Nineteen rows, six columns, and deliberate gaps

The first version laid the elements out in nineteen horizontal rows and six vertical columns, ordered by atomic weight and chemical analogy.

It left gaps on purpose and sometimes broke strict atomic-weight order to keep chemically similar elements together. The paper explicitly proposed atomic weights of 65–75 for missing analogues of aluminium and silicon.

Absent for his own announcement

Mendeleev did not present the work himself. Nikolai Menshutkin communicated the system to the Russian Chemical Society while Mendeleev was inspecting cheese-making operations in the Tver and Novgorod provinces, and printed versions followed later.

The famous detailed predictions for eka-boron, eka-aluminium and eka-silicon belong chiefly to his 1871 paper. This sheet also proposed a reduction of tellurium's atomic weight, which was wrong, even though placing tellurium before iodine was chemically correct.

Sources

Researched 23 Aug 2026 6 sources 2 audit passes Date corrected

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date corrected. The research places this at 1869-03-01.

What the sources leave uncertain

Russia still used the Julian calendar: the manuscript's 17 February date corresponds to 1 March 1869 Gregorian.
The completion/submission date is well supported by the dated manuscript. Historians disagree over the precise later sequence of its presentation, single-sheet circulation and first appearance in print, so this date should not be labeled the day the table was publicly presented or definitively published.