[2734] Bibliothèque Universelle, xxx. (1825) 205; xxx. (1826) 326.
[2735] For a full account of the growth and structure of that rhizome see Luerssen, Medicinisch-pharmaceutische Botanik, i. (1878) 504. 561.
[2736] The chemical nature of this body remains to be ascertained. The crystals are probably Filicic Acid, accompanied by chlorophyl and essential oil.
[2737] Journal de Médecine de Bruxelles, 1867 and 1868—also in the Jahresbericht of Wiggers and Husemann, 1869. 21.
[2738] Cetraria from cetra, an ancient shield of hide, in allusion to the circular apothecia.
[2739] These names are generally applied in Scandinavia and Iceland to the smaller cryptogams, as lichens, true mosses, lycopodium, etc.
[2740] Hist. stirpium, [quoted in the Appendix].
[2741] Bergius, Materia Medica, Stockholm, ii. (1778) 856.
[2742] Flückiger, Documente, quoted at page 404.
[2743] Murray, Apparatus Medicaminum, v. (1790) 510.