If you are an Anglo-Saxon, and make the muscles of your throat rigid, thereby stopping inspiration through the trachea into the thorax, you will soon experience a decided movement of the abdomen, in conformity with which it will first expand anteriorly, then posteriorly, and again anteriorly. There will now be a pause, after which the abdomen will be first expanded posteriorly, then anteriorly, and again posteriorly. This is as far as you can go; you will be compelled to release your hold on your throat after these six movements; the thorax meanwhile remaining passive. Upon next making the muscles of the back of your neck rigid, equal to those of the œsophagus, the latter being thereby closed to respiration, you will soon experience a decided movement of the thorax, by which it will be first expanded posteriorly, then anteriorly, and again posteriorly. There will now be a pause, after which the thorax will be first expanded anteriorly, then posteriorly, and again anteriorly. These twelve movements constitute one act of respiration during which inspiration and expiration for thorax and abdomen equalize each other. The first three movements of the abdomen, consisting of an inspiration, an expiration, and an inspiration, constitute what is commonly called an inspiration; the second three movements of the abdomen, consisting of an expiration, an inspiration, and an expiration, constitute what is commonly called an expiration. Of the six movements of the thorax succeeding these, the first three, consisting of an inspiration, an expiration, and an inspiration, are equal to an inspiration; the last three, consisting of an expiration, an inspiration, and an expiration, are equal to an expiration. We thus have four complete respirations, two of which, equal to an inspiration and an expiration, belong to the abdomen; and two, likewise equal to an inspiration and an expiration, belong to the thorax. Inasmuch as each of these four respirations is composed of three separate movements, one complete respiration consists of twelve separate movements of the respiratory organs. This relates to our ordinary mode of breathing. For vocal utterance, more especially the utterance of a vocal sound, these four respirations are first made for the impression, and are then, in an inverse order, repeated for the expression. This gives us eight movements, or an _octave_ of movements, for each vocal sound; these eight movements, as a matter of fact, consisting of twenty-four separate movements of the respiratory organs. These movements, which in our experiment were of relatively long duration, during our ordinary mode of breathing follow upon one another very rapidly; thorax and abdomen, which during our experiment were restrained, ordinarily and when unrestrained, acting and reacting upon one another in quick succession. The preceding experiment gives us the following result: ABDOMEN