When the experiments were made with various fluids, viz. distilled water, sulphuric acid, concentrated vinegar, alcohol, acetite of lead, acetite of copper, deliquiated potash, ammonia, sulphuric ether, oil of turpentine, and oil of almonds, Mr Achard found that with al most all these fluids, lead and brass had the greatest adhesion ; and wax and sulphur an adhesion gi eater than any of the other metals. The adhesion of gypsum was the least in all the fluids, except the sulphuric acid, to which it adhered with greater force than any of the other discs.
The subject of adhesion has been ably discussed by NI. Dutour in the Journal de Physique. He shows, that the method employed by Taylor and Achard to estimate the adhesive force, is correct only when the solid rises from the fluid surface, without bringing along with it any of the fluid particles, as in the case of glass and mercu ry ; for when the solid brings along with it a quantity of the fluid, as in the case of glass and water, mercury, and some of the metals, the solid does not separate from the fluid at the plane of adhesion, but a little below it, in a plane lying in the substance of the fluid ; so that the weight which produces this separation is rather an ex pression of the cohesion between the particles of the fluid, than of the adhesion of the solid. M. Dutour also
obtained the following results : For further information on this subject, see Phil. Trans. 1721, vol. xxxi. p. 204; 1804. Comment. Reg. Soc. Got ting. 1751, vol. i. p. 501. Miscellan. Taurinens. vol. i. Observations par p. 172, 460 ; vol. xi. p. 127; vol. xiii. Sup. p. 357; vol. xiv. p. 216; vol. xv. p. 46, 234 ; vol. xvi. ; vol. xix. p. 157. Mem. Acad. Berlin, 1776, p. 149. Achard's Chymiseh. Physiche Schriftrn, 1780. Journal de Physique, VOL xlviii. Phil. Mag. vol. xi. p. 27. Gilbert's Journal der Physik, vol. i. p. 396, 515 ; vol. iv. p. 194 ; vol. xii. p. 108. Dr Thomas Young's Lectures on Xat. Phil. vol. ii. p. 652. (w)