Whitney, Language and the Study of Language.

Hovelacque and Vinson, The Science of Language.

Pictet, Origines Indo-Européennes.

Steinthal, Charakteristik der hauptsachlichsten Typen des Sprachbaues.

Civilisation:—

Maine, Ancient Law.

Lubbock, Origin of Civilisation.

Bagehot, Physics and Politics.

Freeman, Comparative Politics; Historical Essays.

Draper, Intellectual Development of Europe.