One of the peculiar fancies I enjoy is medical history. Every couple of years I find myself rereading The Diary of Samuel Pepys, Defoe’s Journal of the Plague Year and William Boghurst’s Loimographia, along with just about anything else that qualifies from that period. That last great outburst of bubonic plague in London in 1665 holds a special fascination. There are few historical comparisons to the sweeping natural evil that malady held, and reading the accounts is enough to chill the blood. Our ancestors were made of stern stuff, though they didn’t have a lot of choice. In an age…