GROTTHUSS, THEODOR VON - THE BASIC LAWS OF PHOTOCHEMISTRY FORMULATED.

Auszug aus vier Abhandlungen physikalisch-chemischen Inhalts. I. Ueber die chemische Wirksamheit des Lichtes und der Electricität, und einen merkwürdigen neues Gegensatz in der erstern, je nachdem das Licht aus nicht oxydirenden oder aus oxydirenden Mitteln unmittelbar in gewisse Substanzen, oder aus ihnen in jene eindringt. II. Merkwürdie Zersetzung des Wassers im Kreise der Volta'schen Batterie. III. Ueber die Verbindung der Anthrazothionsäure (Schwefel-Blaustoffsäure) mit Kobaltoxyd. IV. Zwei neue und kräftige Heilmittel der Heilkunde vindicirt.

Leipzig, Johann Ambrosius Barth, 1819. 8vo. Contemporary half calf. Raised bands, gilt spine. Spine slightly rubbed."Annalen der Physik. Neue Folge. Hrsg. von Ludwig Wilhelm Gilbert", Bd. 61. Small stamps on verso of title-pages. (12),430,(6) pp. and 4 engraved plates. Internally clean and fine.

First appearance of these milestone papers on photochemistry, as it was here the opinion "that only the absorbed light rays are active in the production of chemical changes", was expressed for the first time and "thus, he formulated the importent basic law of photochemistry, which is named after him, "the Grotthuss law of photochemical absorption" (Eder "Histo of Photography" p. 166 ff.). The extracts as offered here, from "Annalen" were published before they appeared in the Annalen der Curländischen Gesellschaft für Litteratur und Kunst.

"This importent Grutthussian thesis was in time so completely forgotten that John William Draper, two years after the inventionof the daguerreotype, discovered the same law and entirely independently of Grotthuss (1841). For a long time it was known as "Draper's Law of absorption" in ignorance of Grotthuss' priority....The four laws of Grotthuss (as formulated in the first paper offered) are....These laws... found little appreciation among his contemporaries...Still we must recognize the fact that the basic ideas which Grotthuss laid down in his photochemical theses were not far removed from the most modern views of physcal chemistry, since the chemical forces of affinity are essentially of an electrical nature".(Eder opt.cit. p. 168).

The volume contains other importent papers Macartney & Tilesius Beobachtungen über leuchtende Thiere" (4 parts), Chladni, E.F.F. "Ueber die Glühlampen" etc. etc.

Order-nr.: 44749