This book describes the miner and the finding of veins. Agricola assumes that his audience is the mine owner, or an investor in mines. He advises owners to live at the mine and to appoint good deputies. It is recommended to buy shares in mines that have not started to produce as well as existing mines to balance the risks. The next section of this book recommends areas where miners should search. These are generally mountains with wood available for fuel and a good supply of water. A navigable river can be used to bring fuel, but only gold or gemstones can be mined if no fuel is available. The roads must be good and the area healthy. Agricola describes searching streams for metals and gems that have been washed from the veins. He also suggests looking for exposed veins and also describes the effects of metals on the overlying vegetation. He recommends trenching to investigate veins beneath the surface. He then describes dowsing with a forked twig although he rejects the method himself. The passage is the first written description of how dowsing is done. Finally he comments on the practice of naming veins or shafts.