Litmus

Litmus, a colouring matter obtained from certain lichens; extensively used in chemical experiments to detect acids, for instance.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Lithuania * Little Corporal
Lipsius, Justus
Lipsius, Richard Adelbert
Lisbon
Lister, Joseph, Lord
Liston, John
Liston, Robert
Liszt, Abbé Franz
Litany
Literature
Lithuania
Litmus
Little Corporal
Little Englanders
Littleton, Sir Thomas
Littré
Liturgy
Liva
Liverpool
Liverpool, Earl of, Robert Jenkinson
Liverymen
Livingstone, David