By Percy Frankland, Ph.D.(Würzburg), B.Sc. (Lond.), F.R.S., and Mrs. Percy Frankland.

Humphry Davy, Poet and Philosopher.

By T. E. Thorpe, LL.D., F.R.S.

Charles Darwin and the Theory of Natural Selection.

By Edward B. Poulton, M.A., F.R.S.

John Dalton and the Rise of Modern Chemistry.

By Sir Henry E. Roscoe, F.R.S.

Major Rennell, F.R.S., and the Rise of English Geography.

By Sir Clements R. Markham, C.B., F.R.S.

Justus von Liebig: his Life and Work (1803–1873).