Elements of agriculture and vegetation. To which is added, an appendix, for the use of practical farmers / [George Fordyce].

  • George Fordyce
Date:
1779
Catalogue details

Licence: Public Domain Mark

Credit: Elements of agriculture and vegetation. To which is added, an appendix, for the use of practical farmers / [George Fordyce]. Source: Wellcome Collection.

    12/126 (page 8)
    / Example, Water will only difiolve a certain Quantity of Salt, and no more. During the Combination, Heat or Cold are often produced: Examples, Vitriolic Acid in uniting with Water, and quick Lime in uniting with Water, generate Heat. Sal Ammoniac and Water, Air and Water, generate Cold. A Menftruum will fometimes diffolve feveral Solvends at a Time, fometimes only one, as Wa¬ ter will diffolve feveral neutral Salts at once, but an Acid will only diffolve one Metal at a Time. The Elements remain combined from the Attra&ion which takes Place between them. TWO SOLIDS mechanically mixed may be feparated; Firft, By Elutriation ; that is feparating twoBodies in Powder by means of Water. If one of the two is of greater fpecific Gravity, or if the Particles of the one, are finer than thofe of the other, and both infoluble in Water; if they be mixed with Water, the heavieft, or that whofe Particles are larged, will fubfide firft, and the Water may be poured off while the other is ftill fwimming in it. Example, Clay and Sand may be feparated in this-Way; the Clay being finer than the Sand, will remain longer fufpen- ded, and therefore may be poured off with the Water. Secondly,