In particular he worked under the attention of Ludwik Rydygier, the famous Polish surgeon who later became professor at the Jagiellonian University of Kraków.

To avoid this fate, an uprising broke out in the city: power was taken over by a "Workers' and Soldiers' Council", which temporarily had control upon the local administration.

He succeeded in having secretly transferred out of hospital Polish soldiers facing death penalty for desertion from the Prussian army, by issuing false documents to allow them to reach safe houses.

[4] Dr. Biziel ran as well an underground hospital, which was organized in the Stryszyk family house at 12 Długa Street during the battles near Bydgoszcz.

[5] In December 1918, Jan participated in the sessions of the Sejm of the district in Poznań as the head of the delegation representing the interests of the Bydgoszcz city.

In 1930, Jan Biziel bought the tenement at 8 3 Maja street, which was managed till after the Second World War by one of his daughters, Pelagia.

Jan Biziel's funeral took place on 7 February 1934, in the Nowofarny Cemetery of Bydgoszcz: in accordance with his last will, the ceremony was kept extremely modest.

In his farewell speech, city president Leon Barciszewski emphasized that Jan Biziel was a man "who disdained nothing more than external glitz, who shy away and escaped from fame and popularity.

Quietly and imperceptibly, he glided through the streets of Bydgoszcz, bringing physical help and spiritual relief to all who called him day and night."

[10] On his initiative, a bookshop promoting Polish language was established in Bromberg at the end of 1911, at the crossing of today's Mostowa and Jagiellońska streets.

[2] The same year, Biziel joined the city Popular National Union and soon became one of its leading members alongside Jan Teska (1876–1945).