Mendeleev's predicted elements
Dmitri Mendeleev published a periodic table of the chemical elements in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest. When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that as-then-unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminium and eka-silicon with atomic masses 44, 68 and 72 respectively.
Food composition data
Food composition tables in the format known today were published towards the end of the 19th century although, some tables on the chemical composition of mineral waters were assembled by Morveau as early as 1780. In 1896, tables from the USA were published, incorporating nearly 2600 analyses of a wide range of foods including the main food groups, as well as some processed foods. Values for foods were presented as ‘refuse’, water, protein, fats, carbohydrates, ash, and ‘fuel value’.