The following passage from Liebig[281] has decidedly much more than a linguistic signification, for it expresses an intimate feeling and comprehension of the way in which a chemical process takes place. "Aldehyd arises, which with the same _avidity_ as sulphurous acid, combines directly with oxygen to form acetic acid."--And again:[282] "Aldehyd, which absorbs oxygen from the air with _great avidity_." As Liebig uses this expression twice in speaking of the same phenomenon, it can hardly be by chance, but rather because it was the only adequate expression for the thing.[283] That most immediate stamp of our thoughts, language, shows us therefore, that every inward impulse must necessarily be conceived as volition; but it by no means ascribes knowledge to things as well. The agreement on this point between all languages, perhaps without a single exception, proves that here we have to do with no mere figure of speech, but that the verbal expression is determined by a deeply-rooted feeling of the inner nature of things. [281] Liebig, "Die Chemie in ihrer Anwendung auf Agrikultur," p. 394. [282] _Ibid._ "Die Chemie in Anwendung auf Physiologie." [283] French chemists likewise say: "_Il est évident que les métaux ne sont pas tous également_ avides _d'oxygène_." ... "_La difficulté de la réduction devait correspondre nécessairement à une_ avidité _fort grande du métal pour l'oxygène_."--(See Paul de Rémusat, "La Chimie à l'Exposition." "L'Aluminium," "Revue des Deux Mondes," 1855, p. 649). Vaninus ("De Amirandis Naturæ Arcanis," p. 170) had said: "_Argentum vivum etiam in aqua conglobatur, quemadmodum et in plumbi scobe etiam: at a scobe non refugit_ (this is directed against an opinion expressed by Cardanus) _imo ex ea quantum potest colligit: quod nequit (scil. colligere), ut censeo_, invitum _relinquit_: natura enim et sua appetit, et vorat." This is evidently more than a form of words. He here quite decidedly attributes a will to quicksilver. And thus it will invariably be found that where, in physical and chemical processes, there is a reference to elementary forces of Nature and to the primary qualities of bodies which cannot be further deduced, these are always expressed by words which belong to the will and its manifestations. [Add. to 3rd ed.] ANIMAL MAGNETISM AND MAGIC.