This looks like a cadaver room at an old medical college. Note the chalk boards for the students to take notes and draw out circulatory systems. There are a number of reasons for the bodies looking emaciated. They are most likely executed prisoners (Thus some were missing their heads) and bodies of the indigent. They were not immediately embalmed and there was no refrigeration. The cadavers may have been preserved with any number chemicals, possibly even kept in a vat of tanners acid until they were needed. I bet the smell was horrendous. Imagine also how sticky, slimy and disgusting they were to dissect.