"but in kind. They are not only ftronger and weak-er, but fome Taftes are fweet and fome bitter;fome Smells are agreeable, and fome offenfive;fome Sounds are acute, and fome grave; and eachof thefe different kinds or qualities too is capableof an immenfe [variety of different modifications*It is the combination of fuch fimple Senfations,as differ not only in degree but in kind, whichconftitutes the compounded Senfation.

Thefe four clalfes of Senfations, therefore, hav-ing none of the qualities which are effential to,and infeparable from, the folid, external, andindependent fubllances which excite them, can-not be qualities or modifications of thofe fubftan-ces. In reality we do not naturally confider themas fuch; though in the way in which we exprefsourfelves on the fubjefl, there is frequently agood deal of ambiguity and confufion. Whenthe different meanings of words, however, are fair-ly diftinguillied, thefe Senfations are, even by themoft ignorant and illiterate, underftood to be,not the qualities, but merely the effedls of' thefolid, external, and independent fubllances uponthe fenfible and living organ, or upon the prin-ciple of perception which feels in that organ.

Philofophers, however, have not in generalfuppofed that thofe exciting bodies produce thofeSenfations immediately, but by the interven-tion of one, two or more intermediate eaufes.

In the Senfation of Tafte, for example, thoughthe exciting body preffes upon the organ of Sen-fation , this preffure is not fuppofed to be the