Jan Ptaszycki (1854-1912)

Jan Ptaszycki was a Polish mathematician working in St. Petersburg in the period 1876--1912. In Poland, he is forgotten, and in Russia considered generally for Russian mathematician, known there as Ivan Lvovich Ptaszycki. There is no article about it on Polish {\it Wikipedia}, while there are three articles in Russian. In historical-mathematical Russian literature, depending on the author, it is reported that Ptaszycki was a Russian mathematician or, more rarely, a Polish mathematician as, for example, in [Lo15a] and [Lo15b]. In Polish, we can find information about it in the dictionaries [DW63], [SW03] and the obituary written by S. Dickstein [Di12], while in Russian in the papers [Pt96]-[Pt16], [Ju68], [Lo15a], [Lo15b], [Od14], and obituary written by Posse [Po12] (reprinted in [Pt3], without providing the author of the article). We underline that important information about Ptaszycki comes from the obituaries of K. A. Posse [Po12] and S. Dickstein [Di12] and from the memoirs of I. Ja. Depman [De60], this is from people who knew him personally. Ptaszycki in 1876 graduated from the University of Petersburg and until the end of his life he worked in  this University. He, obtained a doctor's degree (Polish PhD) in 1881 and a Russian doctorate (Polish habilitation degree) in 1888. He was appointed an associate professor in 1897 and ordinary in 1901. From 1880, he taught in the Tsar Alexander II men gymnasium in Peterhof, from 1883 lectured at the university and from 1891 also at the Mikhailov Academy of Artillery. His main works were devoted to the problem of the so-called integration in finite terms of various types of differentials: algebraic, irrational, elliptical and other.We wanted to make  known to the contemporary reader this forgotten Polish mathematician working in St. Petersburg. We tried to reach his work and achievement in mathematics as well as information about his activity. After discussing his biography, we briefly discuss his mathematical work. At the end of this work, we present a full list of published works and books by Ptaszycki, a list of works where one can find information about him and we quote articles and books related to his scientific achievements.

Jan Ptaszycki był polskim matematykiem pracującym w Petersburgu w latach 1876-1912. W Polsce jest zapomniany, a w Rosji uważany zazwyczaj za rosyjskiego matematyka, znanego tam jako Iwan Lwowicz Ptaszycki. W rosyjskiej literaturze historyczno-matematycznej, w zależności od autora, podaje się, że Ptaszycki był rosyjskim matematykiem lub, rzadziej, polskim matematykiem, na przykład u Łokot (2015, 2018). Ważne informacje o Ptaszyckim pochodzą z nekrologów K. A. Posse (1912) i S. Dicksteina (1912) oraz ze wspomnień I. Ja. Depmana (1960), którzy znali go osobiście. Chcemy przybliżyć współczesnemu czytelnikowi tego zapomnianego polskiego matematyka pracującego w Petersburgu. Po omówieniu jego biografii krótko omawiamy jego prace matematyczne. Na zakończenie artykułu cytujemy artykuły i książki związane z dorobkiem naukowym Ptaszyckiego oraz podajemy pełną listę prac i książek, które opublikował a także listę prac, gdzie można znaleźć informacje o nim.