Note:  Do not rely on this information. It is very old.

Naphthalene

Naphthalene is a hydrocarbon formed by heating many organic substances, and is on this account present in coal-tar, in which it was first discovered in 1819. From this source it may be obtained by allowing the portions of the tar which boil at from 180 to 200 C. to crystallise. After purification it is obtained as a white flaky solid, with a peculiar aromatic odour. It melts at 98, and boils at 218 C, but sublimes readily at lower temperatures. It forms very many important compounds - the naphthalene derivatives, many of which are employed in the manufacture of various dyes. It is employed in the albo-carbon gas-burners, and is also used as an insecticide and preservative.