পাতা:পদার্থবিদ্যাসার.djvu/৮১

70 of our speech : for they who lose many of their teeth are not so easily understood. The lips also serve for the same purpose: hence some of our letters are called labials. Pujo. Have you any thing particular to remark about the throat ; Tut. Yes; in this is an open tube, which we call the wind-pipe, through which, we breathe. Behind this is another, called the gullet, through which she food passes into the stounach. Pup. Must not then our food pass over the open wind-pipe, and consequently be in danger of falling in 2 Tut. So you might weli think. But provision has been made against this. Behind the root of the tongue we find a muscular membrane, which closes the wind-pipe whenever we attempt to swallow any thing, over which the food passes, as if it went across a bridge. Pup. A crumb of bread gives us pain in the throat sometimes; from whence dioes that arise 2 Tut. From its falling into the wind-pipe, (or as we commonly say. going the wrong way :) but this does liot happet, often, unless we laugh or talk while we have our mouth full of food.--Creat wisdoul is also discernible in the structure of the neck. It is form& with so many joints, that we can easily turn the head without moving the whole body; and is provided with stiff bones to keep the head upright, without which man would lose much of his grace and dignity. - - ...We now descend from the head and neck to the body. The larger bones may be considered as the