A D n 



A D H 



TABLE II. 



Tlie furce of aJJicfion between glafs difl;s of different diameters, and different kinds of fluids, determined by 



experiment and calculation. 



Hence it appears, that the difference of adhefion manifeiled 

 by different fized diflcs of glafs with the fame iluid, is in the 

 ratio of the fquares of their diameters ; and this may be 

 admitted as true, at the fame time that it may be doubted 

 ■whether the Table exprcffcs faithfully the refults of the ex- 

 periments. If we bear in mind the firfl of the conditions 

 which M. Achard hlmfelf lays down as effential for the cor- 

 reAncfs of the experiment, namely, that the diil-c {hould be 

 fufpended by the true centre of its mafs and figure, and that 

 the force employed to detach it ffiould always form a right 

 angle with the plane of the dlflc, and of the fluid, it will be 

 obvioiifly extremely difScult to procure the concurrence of 

 thefe circumftances, when operating even with the fmalleft. 

 of the diflcs mentioned in the Table ; and with larger diflcs, 

 the canfes of tiTor mufl increafe at leaft in proportion to the 

 ((juarcs of their diameters. By comparing the differences 



between experiment and calculation, when a ditk 1.75 inch in 

 diameter was ufed, with thofc that took place when a diflc 

 7 inches in diameter was ufed, we fhall find them to be ac- 

 cording to the Table, 0.999799 : 1.000025 ' ■'vhereas, if 

 the probable caufes of error were only as the diameters, the 

 proportion ought to be O.999799 : 4.000100; and if the 

 fquares of the diameters are admitted as the true proportionj- 

 then it fliould be 0.999799 : 21.700542. 



Befides the experiments already mentioned, a feries of 6co 

 more was made by M. Achard, with different folids formed 

 into diflis of equal diameters, and applied to the furface of 

 fome of the fimpler and more compound fluids ; unfortunately 

 feveral of the fohds and fluids are fo heterogeneous in thei» 

 chemical compofition as to afford few important refults ; 

 thofe which are of moll confequence ai;e affcmbled iu the^ 

 following Table ; 



TABLE 



