Scott Hightower (“Monsieur Lavoisier and his Wife,” Jacques-Louis David, 1788; The Metropolitan Museum of Art)   It is the morning of May 8th; Madame Lavoisier has just been orphaned. Within a few more minutes she, likewise, will be widowed; the guillotine, oddly taking the name of a man who did not invent it. May 8th, thus invests itself, not in the talent of one of Jacques-Louis David’s death warrants, but in one set of his...