COMPOSITION OF RIVER WATERS.
PARTS PER MILLION.
| Yukon, Alaska. | Dwina, above Archangel. | St. Lawrence, Pointe des Cascades. | Missouri, Montana. | |
|---|---|---|---|---|
| Potash, K₂O | Trace | 12.58 | 1.40 | 1.90 |
| Soda, Na₂O | 8.10 | 23.38 | 6.90 | 30.10 |
| Lithia, Li₂O | ||||
| Lime, CaO | 30.40 | 37.30 | 45.30 | 58.00 |
| Magnesia, MgO | 7.30 | 36.25 | 9.70 | 18.10 |
| Manganese, Mn₃O₄ | ||||
| Ferric Oxid, Fe₂O₃ | 1.63 | 3.10 | ||
| Alumina, Al₂O₃ | 1.80 | |||
| Silica, SiO₂ | 7.60 | 3.05 | 32.60 | 18.90 |
| Carbonic Acid, CO₂ | 33.00 | 54.01 | 68.40 | 65.20 |
| Phosphoric Acid, P₂O₅ | .40 | Trace | .22 | |
| Nitric Acid, N₂O₅ | ||||
| Sulfuric Acid, SO₃ | 8.50 | 29.62 | 47.70 | 21.90 |
| Chlorin, Cl | .40 | 33.09 | 2.40 | 18.00c |
| Ammonia, NH₃ | ||||
| Total Mineral Matter | 97.10 | 231.31 | 214.40 | 225.42 |
| Less O : Cl | .10 | 7.33 | .55 | 4.10 |
| Corrected Totals | 97.00 | 223.98 | 213.85 | 221.32 |
| Total Solids | 97.00 | 213.85 | 221.22 | |
| F. W. Clarke, Jour. Am. Chem. Soc. Feb. 1905, p. 112. | C. Schmidt, Jahresb. d. Chemie, 1873. | T. S. Hunt, Geol. of Canada, 1863. | Traphagen, Bull. Mont. Expt. Sta. No. 190. | |
| Mississippi near Carrollton, La. | ||||
| Average of one year. | ||||
| Min. | Max. | May 1905. | ||
| Potash, K₂O | 2.80 | |||
| Soda, Na₂O | 19.80c | 13.50 | ||
| Lithia, Li₂O | ||||
| Lime, CaO | 49.75 Dec. | 33.81 Feb. | 41.20 | |
| Magnesia, MgO | 40.80 | 16.39 March | 10.32 Feb. | 11.30 |
| Manganese, Mn₃O₄ | 12.40 | .16 | ||
| Ferric Oxid, Fe₂O₃ | 2.10 | .11 | ||
| Alumina, Al₂O₃ | .17 | |||
| Silica, SiO₂ | 8.70 | 11.45 March | 5.94 April | 7.40 |
| Carbonic Acid, CO₂ | 45.10 | 33.16c | ||
| Phosphoric Acid, P₂O₅ | .33 | |||
| Nitric Acid, N₂O₅ | .13 | .23 | ||
| Sulfuric Acid, SO₃ | 16.10 | 24.72 July | 8.18 Jan. | 23.90 |
| Chlorin, Cl | 9.60 | 4.50 June | 6.90 Dec. | 16.10 |
| Ammonia, NH₃ | .16 | |||
| Total Mineral Matter | 154.73 | 150.52 | ||
| Less O : Cl | 2.10 | 3.63 | ||
| Corrected Totals | 152.63 | 180.0 July | 110.0 Dec. | 146.89 |
| Organic Matter | ||||
| Total Solids | 152.63 | 146.89 | ||
| Porter, Rep. New Orleans Sewerage and Water Board. | Stone, U. S. Reclamation Service. | |||
| Rio Grande, Ft. Craig, N. M. | Nile near Cairo. | Average of the 7 rivers. | Average 19 Great Rivers of the World. | ||
|---|---|---|---|---|---|
| High. Aug. 1874. | Low. May 13, 1875. | ||||
| Potash, K₂O | .80 | 15.01 | 4.04 | 4.80 | 2.40 |
| Soda, Na₂O | 43.40 | 5.87 | 13.01 | 18.20 | 7.10 |
| Lithia, Li₂O | .20 | ||||
| Lime, CaO | 22.80 | 44.22 | 51.78 | 43.50 | 43.20 |
| Magnesia, MgO | 2.10 | 10.33 | 10.29 | 13.10 | 14.70 |
| Manganese, Mn₃O₄ | 1.20 | ||||
| Ferric Oxid, Fe₂O₃ | 1.80 | 2.80 | |||
| Alumina, Al₂O₃ | 1.80 | 3.10 | |||
| Silica, SiO₂ | 11.29 | 6.71 | 10.80 | 16.40 | |
| Carbonic Acid, CO₂ | 10.25 | 42.81 | 40.91 | 38.10 | 46.00 |
| Phosphoric Acid, P₂O₅ | .24 | .30 | |||
| Nitric Acid, N₂O₅ | .18 | 3.80 | |||
| Sulfuric Acid, SO₃ | 47.00 | 18.37 | 29.31 | 26.90 | 8.00 |
| Chlorin, Cl | 36.00 | 6.28 | 17.37 | 15.50 | 3.70 |
| Ammonia, NH₃ | .043 | .014 | .07 | ||
| Total Mineral Matter | 162.35 | 154.223 | 173.434 | 173.12 | 152.97 |
| Less O : Cl | 8.05 | 1.40 | 4.13 | 3.50 | .72 |
| Corrected Totals | 154.30 | 152.823 | 169.304 | 169.62 | 152.25 |
| Organic Matter | 16.4 | ||||
| Total Solids | 154.30 | 164.683 | 200.594 | 169.62 | 168.65 |
| O. Loew, U. S. Geogr. Survey W. of 100th Merid. Vol. 3. | Letheby, Jour. of the Khediv. Agr. Society. | John Murray, Scottish Geogr. Mag., Vol. 3, 1887. | |||
It will be noted that in all the drain waters, lime is the ingredient most abundantly leached out, and as reference to the acids shows, mainly in the form of carbonate, also in that of sulfate. Magnesia is next in amount among the bases; next in amount is soda, largely in the form of sodium chlorid or common salt. Potash is present only in small but rather uniform amounts. Of the acids the carbonic is the most abundant, sulfuric next; chlorin and silicic acid come next, in about equal amounts. Nitric acid passes off in small, but still relatively considerable amounts.
Comparison of the drain waters with the river waters, while showing a general qualitative agreement, also shows a marked diminution of total solids (from 285.7 to 188.7; hence “soft river water”), and especially of lime (from 107.6 to 43.2), together with the carbonic acid with which it is mostly combined; indicating a deposition of lime carbonate in the river deposits or alluvial lands. There is, on the other hand, little if any general difference in the magnesia content of the two classes of waters; nearly the same is true of soda, so that these two bases really show a considerable relative increase when the diminished total is considered. Potash remains about the same all through, viz. two parts or a little more; phosphoric acid shows a fraction of one millionth; nitric acid varies greatly but is usually higher in the drain waters, sometimes showing a heavy depletion of the land by the leaching-out of this important plant food.
It has been computed by John Murray, as quoted by Russell,[11] that the volume of water flowing into the sea in one year, including all the land areas of the earth, is about 6524 cubic miles. From the average composition of river waters as given above, it would follow that nearly five billions (4,975,117,588) of tons of mineral matter are annually carried away in solution from the land into the sea. The amount of sediment carried at the same time is many times greater; in the case of the Mississippi river, it is more than five times the amount of the matter carried in solution.
Comparison of the river waters among themselves shows less of any consistent relation to climatic conditions than might have been anticipated. The waters of the arctic streams Yukon and Dwina show wider differences than any two other waters in the list, unless it be the St. Lawrence, another northern stream. The Missouri and Rio Grande show by their high content of soda, chlorin and sulfuric acid their origin in arid climates, where alkali lands prevail. The water of the Nile is here represented by two analyses,[12] one showing the season when the water is “red” and of high fertilizing quality because of the sediment it brings down from the mountains of Abyssinia; the other the “green” and relatively clear water which comes from the great lakes and through the “sudd ” or grassy swamp region near the junction of the Gazelle river with the Nile. Of the analyses given of the Mississippi river water, the first represents the average of a full year’s observations made weekly under the auspices of the New Orleans Commission on Sewerage and Drainage, by J. L. Porter. The fourth is an analysis made of water taken at the same point in May, 1905; the analysis having been made in full by Mr. Stone, of the Reclamation Service of the U. S. Geol. Survey, the direct determination of potash and soda being in this case included. As will be seen, and might be expected, the average of the Mississippi water corresponds quite nearly to that of nineteen of the world’s great rivers as given by Murray. The very great variation in the content of sulfates is evidently due to the occasional heavy influx of the gypseous waters of the Washita and Red rivers when in flood; while the minimum content (in January) agrees almost precisely with the general average. Murray’s table would hardly be changed if these analyses of Mississippi water were incorporated therein, owing doubtless to the large and varied drainage area of the great river.
Sea Water.—The nature of the substances permanently leached out is also seen by considering the composition of sea water, since the ocean is the final reservoir for all the leachings of the land. It might be objected that the ocean may have received its salts from other sources; but this objection is overborne by the fact that substantially the same salts are found in landlocked lakes, in which, as they have no outflow, the leachings of the adjacent regions are perforce, as a rule, the only possible source of the salts. It is true that the nature of the salts differs somewhat in different lakes, as might be expected; but a general statement of that nature will, after all, be the same as that made in regard to sea-water. The following table of the average composition of sea-water, according to Regnault, illustrates these facts.
MEAN COMPOSITION OF SEA-WATER.
| Sodium Chlorid | (common salt) | 2.700 |
| Potassium chlorid | .070 | |
| Calcium sulfate | (gypsum) | .140 |
| Magnesium sulfate | (Epsom salt) | .230 |
| Magnesium chlorid | (bittern) | .360 |
| Magnesium bromid | .002 | |
| Calcium carbonate | (limestone) | .003 |
| Water (and loss in analysis) | 96.495 | |
| 100.000 | ||