Polish financier of the eighteenth century; court banker under King Stanislaus Augustus Poniatowski (1764-95); date and place of birth unknown; died at Warsaw in 1797. Together with the bankers Dekert and Raffalowitsh he formed the tobacco monopoly in 1776 and the government lottery in 1781. With Tepper he negotiated the Holland loan. In 1790 he was raised to the nobility, and in the following year became the owner of a palace near Senatorska street, Warsaw, and of a villa in the suburb of Fawory. When Ignacy Potozky and Piatoli in 1792 worked out a plan to improve the condition of the Polish Jews, Blanc and his influential friends guaranteed the payment of five million rubles, which the Jews of Poland pledged themselves to contribute, instead of the usual taxes, for the amortization of the king's debts.
- F. Korzon, Wewnetrzne Dzieje Polski za Stanislawa-Augusta (publ. by the Cracow Academy of Science), 1897;
- Em. S—n, Iz Istorii Yevreyev v Polshye, in Voskhod for Oct., 1897;
- S. Orgelbrand, Encyclopedja Powséchna, ii., s.v., Warsaw, 1890.