Ancient Rome and wine Gaul. The Romans established lucrative trading relations with local tribes of Gaul, despite their potential to produce wine of their own. The Gallic tribes paid high prices for Roman wine, with a single amphora worth the value of a slave. From the Mediterranean coast, the Romans pushed further up the Rhone Valley, to areas where olives and figs were unable to grow but where oak trees were still found. As a result of their experience in what is now northeastern Italy, the Romans knew that regions where "Quercus ilex" were found had climates sufficiently warm enough to allow the full
Leyden jar van Musschenbroek of Leiden (Leyden) in 1745–1746. The invention was named after the city. The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electrostatics. The Leyden jar was the first means of accumulating and preserving electric charge in large quantities that could be discharged at the experimenter's will, thus overcoming a significant limit to early research into electrical conduction. Leyden jars are still used in education to demonstrate the principles of electrostatics. The Ancient Greeks already knew that pieces of amber could attract lightweight particles after