The red notebook of Charles Darwin / edited, with an introduction and notes by Sandra Herbert.

  • Charles Darwin
Date:
1980
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Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: The red notebook of Charles Darwin / edited, with an introduction and notes by Sandra Herbert. Source: Wellcome Collection.

    87/184 (page 73)
    THE RED NOTEBOOK 73 which are scattered over the surface of the ground are fibrous, malleable & of so great tenacity, that it is with difficulty that a few fragments can be separated from them with steel instruments.| In R. Brown (Collect: ¿of F. where the stalactiform masses have layers been accumulated, round knobs, or pushed where soft, or [^redissolved soft. — /is there any flexure <(fr) in the fragmentary jasper.—do undulations (as Hutton says)^^^ always come from without. — [continued from previous page] True native iron that to which we cannot attribute a meteoric origin & which is constantly found mixed with lead & copper is infinitely rare in all parts of the globe, p. 113^^® I How utterly incomprehensible that if meteoric stones simply pitched from moon, that the metals should be those which have magnetic properties. Study well products of Solfatarias. some general laws, associa¬ tion of lead & silver. Sulp, of Barytes : Fluoric. Barytes : — | 163e Humboldt. New Spain. Vol III. p. 130^®^ Metals in Mexico rarely in secondary always in primitive & transition; the latter rarely appear in central Cordillera, particularly between 18° & 22° N. = formations of amph : porphyry. greenstoneQj amygdaloid, basalt & other trap cover it to great thickness. = Coast of x\capulco granitic rock. — in parts of table granits & gneiss with gold veins visible: — Porphyries of Mexico may be considered for most parts as rock eminently rich in mines of gold & silver. [p. 13 | 164e The above porphyries characterized by no quartz & amphibole frequently only vitreous felspar : = gold veins in a phonolitic porphyry. = several parts of N. Spain great analogy to Hungary. = Veins of Zimapan offer zeolite, stilbite. grammalite. pyenite. native sulphur., fluor spar, bayte. asbestos garnets.—carb & chrom. of lead, orpiment. Chrysoprase, opal : — Veins in Limestone & Grauwacke : Silver appears far more abundant in the upper limestone, which H. calls by several secondary names I 161 162