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.
Loose leaf lettuce actually covers a variety of lettuce leaves and is defined as lettuce leaves that donât form heads as they grow. Loose leaf lettuce is a great plant for home-growers as the leaves can be frequently picked without halting the growth of the rest of the plant. Butter lettuce, including Bibb and Boston lettuces, are mild green on the outer leaves, yellow-green on the inside, and have a soft, velvety or âbutteryâ texture.