Conductors and Insulators. In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.onductors and Insulators. In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.
Butterhead lettuce. A type of head lettuce whose botanical name is Lactuca sativa var. heirloom. Two common types are Boston and bibb lettuce. Have small, round, loosely formed heads with soft, buttery-textured leaves ranging from pale green on the outer leaves to pale yellow-green on the inner leaves.
Some different types of this lettuce are: Brown Golding, Chaos Mix II black, Chaos Mix II white, Devilâs Tongue, Dark Green Romaine, De Morges Braun, Hyper Red Rumple, Little Leprechaun, Mixed Chaos black, Mixed Chaos white, Nova F3, Nova F4 black, Nova F4 white, Paris Island Cos, Valmaine, and Winter Density, all of which mature within around 70 days.