8vo, beside numerous articles in reviews, journals, newspapers and encyclopaedias, are extant to attest the untiring activity of his mind, and his patient diligence during this period.
Of the earlier encyclopaedias we may notice the famous HandwOrterbuch der reinen and angewandten Chemie, edited by Liebig; Fremy's Encyclopedie de chimie, Wurtz's Dictionnaire de chimie pure et applique'e, Watts' Dictionary of Chemistry, and Ladenburg's HandwOrterbuch der Chemie.
Accounts of the catacombs will also be found in the encyclopaedias and manuals published under the following names: Martigny, Perate, F.
It must suffice, therefore, to deal rather broadly with the subject, and to refer for fuller details to the special encyclopaedias, viz.: Hamburger's RealEncyc. fiir Bibel and Talmud, and the very elaborate articles in the Jewish Encyclopedia.
Of encyclopaedias may be mentioned the New SchaffHerzog Encyclopaedia of Religious Knowledge (New York, 1908 sqq.); the Catholic Encyclopaedia (New York, 1907 sqq.); Herzog-Hauck, Realencyklopcidie (3rd ed., Leipzig, 1896 sqq.); Wetzer and Welte, Kirchenlexikon (2nd ed., Freiburg-im-Breisgau, 1882-1901); G.