"From the Unseen Darkness where the vineroots suck, where the liquid in your glass is teased our of the soil." So states Hugh Johnson in exlpaining the importance of soils, "the terroir" that the French have long praised as the secret to great wines. Years of meticulous research now reveal the relationship between rocks and grapes. A natural history of the little known facts and anecdote woven into the compelling tale of how geology influences the choice of grapes, style and quality. A master geologist describes each rock type and soil and the way structure affects the absorption of vital nutrients. Using instruments and techniques developed for oil exploration, Wilson learned more about vineyards and quality than winemakers ever dreamed! Foreward by Hugh Johnson. Includes illustrations, glossary, maps and charts.