Added to the JURN site-index today:—
Critical Disability Discourse (Seems to welcome papers from various disciplines. First issue has an article on aesthetics and ethics)
Medical History (History of Medicine. On PubMed, but genuinely free. Google/JURN is only able to index the TOCs from 2000 to 2009, despite the journal having issues online from 1957 onwards)
History of Physics newsletters (Has regular book reviews)