Gregor Mendel

Rare manuscript DS in German, one page, 8.5 x 13.75, 1868. Receipt document concerning a financial transaction, issued from St. Thomas's Abbey in Brno. In full (translated): "For 63 florins, that is, sixty-three Austrian guldens, at 5 % interest, for the period from 1 September 1867 up to now in 1868, that the satisfied monastery has received in cash from the endowment capital of 1200 convention florins secured by the Pernstein manor and the manorial rights there." An official embossed red wax seal is affixed to the lower left, with two revenue stamps affixed near the top. In fine condition.

Mendel conducted his principal pea plant experiments between 1856 and 1863, developing the laws of inheritance through his observations. He coined the terms 'recessive' and 'dominant' to refer to the invisible 'factors' that influenced heredity (now known as genes), and his principal paper on the subject was published in 1866. In 1868, the year of this document, he was elevated to abbot of the monastery and his new responsibilities gave him little time to devote to scientific studies. He spent most of his time attempting to keep the monastery financially afloat and, following his death, the succeeding abbot burned many of the papers in Mendel's collection to mark an end to the financial troubles. Autographic material by the groundbreaking scientist is thus very difficult to come by and exceptionally desirable worldwide.