Julius von Sachs (1832-1897) was a German botanist from Breslau, Prussian Silesia. In Sachs 'History of Botany' he has made it his chief object to discover the first dawning of scientific ideas and to follow them as they developed into comprehensive theories, for in this lies the true history of a science. Sachs singles out those men as the true heroes of our story who not only established new facts, but gave birth to fruitful thoughts and made a speculative use of empirical material.