The elements carbon, oxygen, hydrogen, and nitrogen pass through a cycle of changes from simple inorganic substances to the complex compounds of the living cell. Upon the decomposition of these bodies the elements return to their original state. During this transition those properties of protoplasm which were mentioned at the beginning, in turn, follow their path. From germination to death this course appears like a crescent, the other half of the circle closed from view. Where chemistry begins and ends it is difficult to say.--_Jour. Fr. Inst._ [Footnote 1: A lecture delivered before the Franklin Institute, January 24, 1887.] [Footnote 2: Studien uber das Protoplasm, 1881.] [Footnote 3: Vines, p. 1. Rostafinski: Mem. de la Soc. des Sc. Nat. de Cherbourg, 1875. Strasburger: Zeitschr., xii, 1878.] [Footnote 4: Botany: Prantl and Vines. London, 1886, p. 110.] [Footnote 5: For the literature of starch, see p. 115, Die Pflanzenstoffe, von Hilger and Husemann.] [Footnote 6: Kutzing: Arch. Pharm., xli, 38. Kraus and Millardet: Bul. Soc. Sciences Nat., Strasbourg, 1868, 22. Sorby: Jour. Lin. Soc., xv, 34. J. Reinke: Jahrb. Wissenscht. Botan., x, B. 399. Phipson: Phar. Jour. Trans., clxii, 479.] [Footnote 7: Prantl and Vines, p. 111.] [Footnote 8: L. Crie: Compt. Rend., lxxxviii, 759 and 985. J. De Seynes, 820, 1043.] [Footnote 9: Page 279.] [Footnote 10: M. Nencki and F. Schaffer. N. Sieher: Jour. Pract. Chem., 23, 412.] [Footnote 11: E. Klein: Quar. Jour. Micros. Science, 1875, 381. O. Helm: Arch. Pharm., 1875, 19-24. G. Gugini: Gaz. Chem., 7, 4. W. Thorner: Bul. Ber, xi, 533.] [Footnote 12: Handbook of Dyeing. By W. Crookes, London, 1874. p. 367. Schunck: Ann. Chem. Pharm., 41, 157; 54, 261; 61, 72; 61, 64; 61, 78. Rochelder and Heldt, ibid., 48, 2; 48, 9. Stenhouse, ibid., 68, 57; 68, 72; 68, 97, 104; 125, 353. See also researches of Strecker, O. Hesse, Reymann, Liebermann, Lamparter, Knop, and Schnedermann.] [Footnote 13: Stahlschmidt.] [Footnote 14: E. Treffner: Inaugur. Diss. Dorpat, 1880.] [Footnote 15: W. Pfeffer: Flora, 1874.] [Footnote 16: Die Pflanzenstoffe, p. 323 W. Lange: Bul. Ber., xi, 822.] [Footnote 17: Ann. Chim. Phys., 41, 62, 208; Ann. Chim. Pharm., 77, 295.] [Footnote 18: Fluckiger: Pharmakognosie. Kamp: Ann. Chim. Pharm., 100, 300.] [Footnote 19: Revue Scientifiqe, 13 Mars, 1886.] [Footnote 20: Dictionary of Economic Plants. By J. Smith. London, 1882, p. 294.] [Footnote 21: Ibid., p. 160. Pharmakognosie des Pflanzenreichs, Wittstein, p. 736. Ann. Chem. Pharm., 77, 295.] [Footnote 22: Rabenhorst: Repert. Pharm., lx, 214. Moore: Chem. Centralbl., 1862, 779, Dana.] [Footnote 23: Johansen: Arch. Pharm., 3, ix, 210. Ibid., 3, ix 103. Bente: Berl. Ber., viii, 476. Braconnot: Ann. Chim. Phys., 2, 44, 296.] [Footnote 24: Wittstein; Pharm. des Pflanzenreichs, p. 249.] [Footnote 25: John; Ibid., p. 651.]