Much has been written on Claude Bernard as a relentless promoter of the experimental method in physiology. Although the paper will touch Bernard’s experimental intuitions and his experimental practice as well, its focus is slightly different. It will address the laboratory, that is, the space in which experimentation in the life sciences takes place, and it will analyze the scattered remarks that Bernard made on the topic both in his books and in his posthumously published writings. The paper is divided (...) into four parts. The introduction briefly sketches the coming into being of the physiological laboratory in the first half of the nineteenth century. The second section will give an overview of Claude Bernard’s own itinerary in physiology and his personal laboratory experience. The third part of the paper will have a look at the image of the laboratory that Claude depicted in his Introduction to Experimental Medicine. In the subsequent section and by contrast, the image of the laboratory will come into focus as it can be reconstructed from Bernard’s notebook that he kept between 1850 and 1860, the Cahier rouge. Finally, the fifth part of the paper will spotlight Claude Bernard’s comparison of the sciences and the arts and their respective practices. A brief concluding statement tries to summarize Bernard’s epistemological position toward experimentally practiced science. (shrink)