Epithelioma of the Thyroid Gland and Trachea
The Journal of Laryngology and Rhinology
depression and drawing in of the lower ribs, and consequent diminution of the area of the floor of the chest cavity. This is well illustrated by cases ; , of chronic emphysema. ' •;' Now, in order to judge of the relative merits of these two forms of inspiration, we have only to regard the chest cavity as a cone, and apply : the ordinary mathematical formula for such: V = ~ TT r". We can : now see at a glance that the volume of the chest can only be materially " increased by increasing the area
... increasing the area of the base, or, in other words, by elevating the crown of the diaphragm, and thereby elevating and expanding the lower ribs, r representing the radius of the base of the cone, however small the increase of r r, is squared ; whilst on the other hand // representing the height of the cone, whatever the increase of//, it is ; always to be divided by 3. We know, however, from anatomical "' reasons, h can never exceed an inch to an inch and a half. ' From this then it would appear that the proper method of inflating • : the chest for singing and speaking purposes is to draw in the stomach \ and elevate the ribs, and that after all the old Italian School was right.