Elements of Agricultural Chemistry: In a Course of Lectures for the Board of Agriculture (Google eBoek)

Voorkant
John Conrad & Company, 1815 - 332 pagina's
0 Recensies
  

Wat mensen zeggen - Een recensie schrijven

We hebben geen recensies gevonden op de gebruikelijke plaatsen.

Veelvoorkomende woorden en zinsdelen

Populaire passages

Pagina 242 - ... soon become diffused through the mass of the surrounding air. The great object in the application of manure should be to make it afford as much soluble matter as possible to the roots of the plant : and that in a slow and gradual manner, so that it may be entirely consumed in forming...
Pagina 23 - Nothing is more wanting in agriculture than experiments in which all the circumstances are minutely and scientifically detailed. This art will advance with rapidity in proportion as it becomes exact in its methods.
Pagina 278 - Less siliceous earth was given by the plants than by the grains ; but their ashes yielded much more carbonate of lime. That there was less siliceous earth, I attribute to the circumstance of the husk of the oat being thrown off in germination ; and this is the part which most abounds in silica. Healthy green oats, taken from a growing crop, in a field of which the soil was a .fine sand, yielded siliceous earth in a much' greater proportion than an equal weight of the corn artificially raised.
Pagina 273 - If a thermometer plunged into the dung does not rise to above 100 degrees of Fahrenheit, there is little danger of much aeriform matter flying off. If the temperature is higher, the dung should be immediately spread abroad. When a piece of paper moistened in muriatic acid held over the steams arising from a dunghill gives dense fumes, it is a certain test that the decomposition is going too far, for this indicates that volatile alkali is disengaged.
Pagina 141 - ... siliceous ; and in this case, and in analogous cases, the portions different from each other should be separately submitted to experiment. Soils when collected, if they cannot be immediately examined, should be preserved in phials quite filled with them, and closed with ground glass stoppers. The quantity of soil most convenient for a perfect analysis is from two to four hundred grains. It should be collected in dry weather, and exposed to the atmosphere till it becomes dry to the touch. The...
Pagina 37 - ... of remarkable chemical powers. The luminous phenomena produced by common electricity are well known. It would be improper to dwell upon them in this place. They are the most impressive effects occasioned by this agent ; and they offer illustrations of lightning and thunder. Electrical changes are constantly taking place in nature, on the surface of the earth, and in the atmosphere ; but as yet the effects of this power in vegetation have not been correctly estimated. It has been shown by experiments...
Pagina 185 - ... in its solid form. Snow and ice are bad conductors of heat ; and when the ground is covered with snow, or the surface of the soil or of water is frozen, the roots or bulbs of the plants beneath are protected by the congealed water from the influence of the atmosphere, the temperature of which in northern winters is usually very much below the freezing point ; and this water becomes the first nourishment of the plant in early spring. The expansion of water during its congelation...
Pagina 256 - Fish forms a powerful manure, in whatever state it is applied ; but it cannot be ploughed in too fresh, though the quantity should be limited. Mr. Young records an experiment, in which herrings spread...
Pagina 270 - ... cubical inches of carbonic acid, the remainder was hydrocarbonate mixed with some azote, probably no more than existed in the common air in the receiver. The fluid matter collected in the receiver at the same time amounted to nearly half an ounce. It had a saline taste, and a disagreeable smell, and contained some acetate and carbonate of ammonia.
Pagina 250 - Rape cake, which is used with great success as a manure, contains a large quantity of mucilage, some albuminous matter, and a small quantity of oil. This manure should be used recent, and kept as dry as possible before it is applied. It forms an excellent dressing for turnip crops ; and is most ceconomically applied by being thrown into the soil at the same time with the seed.

Bibliografische gegevens