From J. H. Gilbert 9 January 1882
Summary
Thanks CD for Earthworms.
Discusses the problem of accounting for difference between nitrogen in permanent grassland and ordinary arable soil. Finds castings of earthworms rich in nitrogen. Asks CD if his observations enable him to explain the source. If from below top-soil, it would be a considerable manuring.
| Author: | Joseph Henry Gilbert |
| Addressee: | Charles Robert Darwin |
| Date: | 9 Jan 1882 |
| Classmark: | DAR 165: 45 |
| Letter no: | DCP-LETT-13605 |
To J. H. Gilbert 12 January 1882
Summary
Quantity of nitrogen in castings surprises CD.
Comments on papers: [J. B. Lawes and J. H. Gilbert, "Results of experiments on mixed herbage, pt 1", Philos. Trans. R. Soc. Lond. 171 (1880): 289–416; Gilbert, Lawes and M. T. Masters, "pt 2: The botanical results", Philos. Trans. R. Soc. Lond. 173 (1882): 1181–413].
Has never made sections to see how deep worms burrow – five or six feet is probable. Wishes the problem had arisen when he made his observations.
| Author: | Charles Robert Darwin |
| Addressee: | Joseph Henry Gilbert |
| Date: | 12 Jan 1882 |
| Classmark: | Rothamsted Research (GIL13) |
| Letter no: | DCP-LETT-13616 |
| letter | (2) |
| Darwin, C. R. | (1) |
| Gilbert, J. H. | (1) |
| Darwin, C. R. | (1) |
| Gilbert, J. H. | (1) |
| Darwin, C. R. | (2) |
| Gilbert, J. H. | (2) |
