This record of Bernard's actual lectures contains the first published description of Bernard's technique of right and left heart cathererization, a technique that Bernard invented. The appendix includes notes of lectures by Charles Robin. Digital facsimile from the U.S. National Library of Medicine at this link.
Bernard published a detailed account of the procedure in "Recherches experimentales sur la temperature animale," Comptes rendus Acad. Sci, 43, 551-569. He undertook the proceedure in an attempt to study the difference in temperature between the two circulations.