Elements of Agricultural Chemistry and GeologyC.M. Saxton, 1851 - 249 páginas |
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Página 80
... crumble away . Such is the case even with many of those which , on account of their greater hardness , are employed ... crumbled . Led by this observation , the geologist , after comparing the rocks of different countries with one ...
... crumble away . Such is the case even with many of those which , on account of their greater hardness , are employed ... crumbled . Led by this observation , the geologist , after comparing the rocks of different countries with one ...
Página 88
... crumble under the action of the winter's frost . Hence in York , shire , Wiltshire , Hampshire , and Kent , where the lower chalk covers the surface , or is found at no great depth beneath it , it is dug out of the sides of the hills ...
... crumble under the action of the winter's frost . Hence in York , shire , Wiltshire , Hampshire , and Kent , where the lower chalk covers the surface , or is found at no great depth beneath it , it is dug out of the sides of the hills ...
Página 89
... crumble or are worn down , pro- duce soils possessed of some peculiarity by which their general agricultural capabilities are more or less affected , and these peculiarities may gener- ally be observed in soils formed from rocks of the ...
... crumble or are worn down , pro- duce soils possessed of some peculiarity by which their general agricultural capabilities are more or less affected , and these peculiarities may gener- ally be observed in soils formed from rocks of the ...
Página 98
... crumble down into rich red soils . Such are the soils of Brecknock , Hereford , and part of Monmouth ; of part of Berwick and Roxburgh ; of Haddington and Lanark ; of southern Perth ; of either shore of the Moray Firth ; and of the ...
... crumble down into rich red soils . Such are the soils of Brecknock , Hereford , and part of Monmouth ; of part of Berwick and Roxburgh ; of Haddington and Lanark ; of southern Perth ; of either shore of the Moray Firth ; and of the ...
Página 120
... crumbled to dust , been strewed over the surface in alternate layers , and afterwards again consolidated , the reader will readily grant , that in all rocks , and consequently in all soils , traces of every one of these substances may ...
... crumbled to dust , been strewed over the surface in alternate layers , and afterwards again consolidated , the reader will readily grant , that in all rocks , and consequently in all soils , traces of every one of these substances may ...
Outras edições - Ver tudo
Elements of Agricultural Chemistry and Geology James Finlay Weir Johnston Visualização integral - 1842 |
Elements of Agricultural Chemistry and Geology James Finlay Weir Johnston Visualização integral - 1842 |
Elements of Agricultural Chemistry and Geology James Finlay Weir Johnston Visualização integral - 1842 |
Palavras e frases frequentes
abundance agricultural alumina ammonia arable land ash of plants barley beds beneath burned carbonic acid cent chalk charcoal chemical chiefly common salt compost compounds consists constitution contain corn crops crumble decay districts drains dung earthy matter effect farm farm-yard manure farmer felspar fermented fertile geology gluten gradually grain granites grass green grow growth gypsum Hence hornblende hydrogen improvement inorganic food inorganic matter kind leaf leaves less lime limestone magnesia marl mixed natural nitric acid nitrogen nourishing numbers oats organic oxygen peat Phosphoric acid plough portion potash potatoes practical produce proportion quantity of inorganic quicklime rains readily red sandstones rich roots saline matter sand sandy SECTION III.-OF seed silica Silurian soda soil solid soluble starch stiff clay stratified rocks subsoil sugar sulphate Sulphuric acid supply surface tain tion turnip varies VEGETABLE MANURES vegetable matter weight wheat wheat straw woody fibre yield
Passagens conhecidas
Página 42 - But the latter process does not go on so rapidly as the former ; so that, on the whole, plants when growing gain a large portion of carbon from the air.
Página 48 - Ib. - - 371 - - 87£ of ulmic acid. 501b. - - 78* - - 122it 5011). 56 106 of vinegar. In the interior of the plant, therefore, it is obvious that, whichever of these substances be present in the sap, the elements are at hand out of which any of the others may be produced. In what way they really are produced, the one from the other, and by what circumstances these transformations are favoured, it would lead into too great detail to attempt here to explain. (For fuller and more precise explanations...
Página 178 - ... compared with those of vegetable matters and with each other, can be pretty nearly estimated. In reference to their relative quantities of nitrogen, therefore, they have been arranged in the following order, the number opposite to each representing the weight in Ibs. which is equivalent to or would produce the same sensible effect upon the soil as lOOlbs.
Página 34 - Pure nitric acid consists of nitrogen and oxygen only ; the union of these two gases, so harmless in the air, producing the burning and corrosive compound which this is known to be. " It never reaches the roots of plants in this free and corrosive state. It exists in many soils, and is naturally formed in compost heaps, and in most situations where vegetable matter is undergoing decay in contact with the air ; but it is always in a state of chemical combination in these cases. With potash, it forms...
Página 44 - When a seed is committed to the earth, if the warmth and moisture are favorable it begins to sprout. It pushes a shoot upwards, it thrusts a root downwards ; but until the leaf expands and the root has fairly entered the soil, the young plant derives no nourishment other than water, either from the earth or from the air. It lives on the starch and gluten contained in the seed.
Página 73 - If 100 grains of clay soil leave no more than 10 of clay, it is called a sandy soil : if from 10 to 40, a sandy loam ; if from 40 to 70, a loamy soil ; if from 70 to 85, a clay loam ; if from 85 to 95, a strong clay soil.
Página 81 - the general result of the comparison of the soils of various districts with the rocks on which they immediately rest, has been that in almost every country the soils have as close a resemblance to the rocks beneath them, as the loose earth derived from the crumbling of a rock before our eyes bears to the rock of which it lately formed a part." The conclusion, therefore, is irresistible, that soils, generally speaking, have been formed by the crumbling or decay of the solid rocks — that there was...
Página 36 - The air we breathe, and from which plants also derive a portion of their nourishment, consists of a mixture of oxygen and nitrogen gases, with a minute quantity of carbonic acid, and a variable proportion of watery vapour. Every hundred gallons of dry air contain about 21 gallons of oxygen and 79 of nitrogen. The carbonic acid amounts only to one gallon in...
Página 44 - is committed to the earth, if the warmth and moisture are favourable, it begins to sprout. It pushes a shoot upwards, it thrusts a root downwards ; but, until the leaf expands, and the root has fairly entered the soil, the young plant derives no nourishment other than water, either from the earth or from the air. It lives on the starch and gluten contained in the seed.
Página 43 - ... told upon the authority of Professor Johnson, that upon lands of average fertility from one-third to four-fifths of the entire amount of carbon contained in the crop is obtained from the air ; and to catch the small amount of carbonic acid the tree hangs out thousands of square feet of leaf surface, in perpetual motion through an ever-moving air, and thus by the conjoined labours of millions of pores the substance of whole forests of solid wood is slowly extracted from the fleeting winds.