Caius Plinius Secundus c.A.D. (23 - 79 AD) was a Roman naturalist, friend and soldier of Vespasian. His great work was dedicated to Vespasian's son and future emperor Titus. His single surviving work, Historia Naturalis, is a rich, in depth encyclopedia on natural science in the Roman world. In 37 books, he covered geography, anthropology, zoology, botany, medicines and mineralogy.
He was an immense source of knowledge on these subjects, but his work is mainly a collection of facts as it was known in the ancient world. As a scientific study, it is failing in light of modern knowledge, but a historical reference to the science of the Romans it's an invaluable resource. Pliny was so dedicated to his pursuits that he died of asphyxiation while researching the eruption of Vesuvius and subsequent destruction of Pompeii.
Historia Naturalis (Natural Histories)