[2] His first research paper, "Thermochemical Analysis of Organic Compounds" was published in 1908, in "Polish Yearly Magazine ("Rocznik Polski").

In the mid-, and late 1910, Świętosławski remained in Moscow, working, among others, on Aromatic hydrocarbon, Nitric acid, Nitro compound, Amine, and burning in bomb calorimeters.

In 1918 Świętosławski returned to Poland, leaving his laboratory in Moscow and urging other highly qualified Polish scientists to follow him.

In 1919, he was named Professor of Physical Chemistry at Warsaw University of Technology, and returned to scientific research, working on enthalpy of vaporization.

In 1922, his motion was accepted, and Świętosławski was named head of the Thermochemical Data Commission, which coordinated research on marking the heat of combustion.

He constructed microcalorimeters, which worked in isometric and adiabatic conditions as well as microcalomieters based on partial heat exchange with the surroundings.

From November 1935 until 1939, Świętosławski was Minister of Religious Denominations and Public Enlightenment in the governments of Marian Zyndram-Kościałkowski and Felicjan Sławoj Składkowski.