Charles Darwin; his life and work / by Charles Frederick Holder.

  • Charles Frederick Holder
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: Charles Darwin; his life and work / by Charles Frederick Holder. Source: Wellcome Collection.

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    cember, 1842, Darwin, waiting twenty-nine years, or until November, 1871, before noting the results; a trench was then dug across the field exposing a series of white dots or nodules ; the original deposit of chalk being found on both sides of the trench at a depth of seven inches from the surface. Another portion of this field was spread with cinders in 1842, and twenty-nine years later the stratum was also found seven inches below the surface, so that Dar- win assumed that the mould, exclusive of the turf, had b een thrown up at an average rate of .22 inches per year. These and other experiments resulted in the work, Formation of Vegetable Mould, published in 1882. All experiments were carried on in the same methodical manner, exactness, conclusiveness, and simplicity being the characteristics of all the work of the great naturalist.