System of Theoretical and Practical Chemistry ...

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Página 376 - ... earthy, animal, or vegetable matter, will remain in a state of mechanical suspension for a much longer time ; so that by pouring the water from the bottom of the vessel, after one, two, or three minutes, the sand will be principally separated from the other substances, which, with the water containing them, must be poured into a filter, and after the water has passed through, collected, dried, and weighed.
Página 382 - ... a correction must be made for the general process, by subtracting a sum equal to their weight from the quantity of carbonate of lime obtained by precipitation from the muriatic acid. In arranging the products, the form should be in the order of the experiments by which they were procured.
Página 386 - Lothian afforded in a hundred parts only eleven parts of mild calcareous earth; the finely divided clay amounted to forty-five parts. It lost nine in decomposed animal and vegetable matter, and four in water, and exhibited indications of a small quantity of phosphate of lime. This soil was of a very fine texture, and contained very few stones or vegetable fibres. It is not unlikely, that its fertility was in some measure connected with the phosphate; for this substance is found in wheat, oats, and...
Página 375 - It is of importance, that the specific gravity of a soil should be known, as it affords an indication of the quantity of animal and vegetable matter it contains ; these substances being always most abundant in the lighter soils. The other physical properties of soils should likewise be examined before the analysis is made, as they denote, to a certain extent, their composition, and serve as guides in directing the experiments. Thus siliceous soils are generally rough to the touch, and scratch glass...
Página 387 - I found the soil taken from a field at Sheffield-place, in Sussex, remarkable for producing flourishing oaks, to consist of six parts of sand, and one part of clay and finely divided matter ; and one hundred parts of the entire soil, submitted to analysis, produced, Water 3 parts Silex 54 Alumine 28 Carbonate of lime .... 3 Oxid of iron 5 Decomposing vegetable matter . 4 Loss 3 20.
Página 387 - Plants and trees, the roots of which are fibrous and hard, and capable of penetrating deep into the earth, will vegetate to advantage in almost all common soils that are moderately dry, and do not contain a very great excess of vegetable matter.
Página 376 - The loss of weight in the process should be carefully noted, and when in 400 grains of soil it reaches as high as 50, the soil may be considered as in the greatest degree absorbent, and retentive of water, and will generally be found to contain much vegetable or animal matter, or a large proportion of aluminous earth.
Página 379 - Carbonate of lime, in all its states, contains a determinate proportion of carbonic acid, ie nearly 43 per cent., so that when the quantity of this elastic fluid given out by any soil during the solution of its calcareous matter in an acid is known, either in weight or measure, the quantity of carbonate of lime may be easily discovered.
Página 383 - When the experimenter is become acquainted with the use of the different instruments, the properties of the re-agents, and the relations between the external and chemical qualities of soils, he will seldom find it necessary to perform, in any one case, all the processes that have been described. When his soil, for instance, contains no notable proportion of calcareous matter, the action of the muriatic acid (7) may be omitted. In examining peat soils, he will principally have to attend to the operation...
Página 351 - In the last-mentioned case, however, the change will either cease to appear, or will be much less remarkable, when the water has been boiled. 4. Syrup of violets, when pure, is, by the same causes, turned green ; as...

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