Leaving my SO in bed at the hotel with a nasty bacterial infection and some antibiotics, I went with timely irony to visit the home and laboratory of Louis Pasteur at the Institut Pasteur. (It's pretty easy to find since it has a conveniently named stop on the Paris metro: Pasteur).
At the Institut Pasteur there's a wonderful museum that covers the life and work of Louis Pasteur (and his wife). It's housed in the building (above) where the Pasteurs lived. There's a single room of Pasteur's science and the rest of the house is Pasteur's home; so a visit is partly scienfitic and partly like visiting any old home. I was mostly interested in the laboratory (although seeing how he lived---pretty darn well!---was also worth it).
Pasteur wrote standing up at a raised table (much like old bank clerks used to use) and his lab is full of specimens that he worked on. There's a nice display about chirality which Pasteur had initially worked on while study tartaric acid in wine. (Pasteur determined that there were two forms of tartaric acid by painstakingly sorting tiny crystals by hand).
The rest of the lab covers immunization, pasteurization and the germ theory of disease. There was a nice display of Pasteur's bottles of chicken broth that he used to demonstrate the germ theory of disease. The bottles contain boiled broth and have a long tapering curved neck. Although the neck is open the shape prevents dust from entering and the broth sits undisturbed (as it has for 150 years).
In the same room there's also a big bottle of horse's blood that looks fresh despite its age, and there are detailed displays about immunization (and especially Pasteur's rabies vaccine).
The museum also has a lot of equipment used by Pasteur, such as vacuum pumps and autoclaves. It all has that lovely Victorian feel of wrought iron and brass.
The oddest part of the museum is the Pasteurs' burial chamber built beneath the house and in a totally over the top Byzantine style.
Note that the museum is only open in the afternoons during the week and that you must bring photo ID with you to get in since it is inside the Institut Pasteur.