Pliny the Elder, tireless researcher and writer, is author of the encyclopedic ''Natural History,'' in 37 books, an unrivaled compendium of Roman knowledge. The contents of the books are as follows. Book 1: table of contents of the others and of authorities; 2: mathematical and metrological survey of the universe; 3-6: geography and ethnography of the known world; 7: anthropology and the physiology of man; 8-11: zoology; 12-19: botany, agriculture, and horticulture; 20-27: plant products as used in medicine; 28-32: medical zoology; 33-37: minerals (and medicine), the fine arts, and gemstones. The Loeb Classical Library edition of Natural History is in ten volumes.