and it is also remarkable that in Finnish, antaa sunta, "to kiss," means literally "to give mouth."
How does the mouth produce a kiss?
A kiss is produced by a kind of sucking movement of the muscles of the lips, accompanied by a weaker or louder sound. Thus, from a purely phonetic point of view, a kiss may be defined as an inspiratory bilabial sound, which English phoneticians call the lip-click, i.e., the sound made by smacking the lip. This movement of the muscles, however, is not of itself sufficient to produce a kiss, it being, as you know, employed by coachmen when they want to start their horses; but it becomes a kiss only when it is used as an expression of a certain feeling, and when the lips are pressed against, or simply come into contact with, a living creature or object.
The sound which follows a kiss has been carefully investigated by the Austrian savant, W. von Kempelen, in his remarkable book entitled The Mechanism of Human Speech (Wien, 1791). He divides kisses into three sorts, according to their sound. First he treats of kisses proper, which he characterises as