Just repeat this phrase to yourself—“hemorrhaging blood from every orifice”—and you’ve got an indication of why the Ebola virus holds such a morbid fascination. This is just one of the spectacularly gruesome symptoms of the virus, subject of Richard Preston’s best-seller The Hot Zone and currently suspected of burning though a town in the Zairian outback (body count at press time: 86). While Ebola may be the most photogenic new virus, it’s not the only scary bug that’s making periodic attempts to break into the human population. In “Microscopic Enemies: The Threat of Emerging Viruses,” virologist Frederick A. Murphy will lecture on the characteristics of these new diseases and show pictures of our tiniest pred ators. At 8 p.m. at the Museum of Natural History’s Baird Auditorium, 10th & Constitution Ave. NW. $13. For reservations call (202) 357-3030. (Steve Kuhn)