NOTE III. (p. 303).
Composition of Concretionary Nodules.
(Analyses by Karmrodt.)
| No. 1 | |
| Potassium sulphate | 7.49 |
| Potassium phosphate | 9.52 |
| Sodium phosphate | 9.08 |
| Ammonium phosphate | 7.57 |
| Calcium sulphate | 3.40 |
| Ammonium urate | 4.09 |
| Ammonium oxalate | 41.28 |
| Nitrogenous organic matter | 10.17 |
| Water | 7.40 |
| 100.00 | |
| Nitrogen - 14.84 | |
| No. 2 | |
| Potassium sulphate | 45.64 |
| Sodium sulphate | 13.22 |
| Ammonium sulphate | 10.23 |
| Ammonium oxalate | 9.14 |
| Basic ammonium phosphate | 12.09 |
| Precipitated ammonium phosphate | 4.78 |
| Organic matter | .94 |
| Insoluble | 1.90 |
| Water | 2.06 |
| 100.00 | |
The following analyses, being the average of a large number of different samples analysed from time to time in the chemical laboratory of the Pommritz Agricultural Experimental Station, show the gradual deterioration of Peruvian guano, as regards its percentage of nitrogen, during the years 1867-81:—
| Nitrogen. | |
| 1867 | 13.16 |
| 1868 | 11.98 |
| 1869 | 13.66 |
| 1870 | 12.37 |
| 1871 | 10.04 |
| 1872 | 10.72 |
| 1873 | 9.16 |
| 1874 | 9.83 |
| 1878 | 7.10 |
| 1879 | 6.95 |
| 1880 | 7.07 |
| 1881 | 6.93 |
NOTE V. (p. 309).