new beings out of nothing, but any thing may be called new, when it is altered from one figure into another. I add no more at this time, but rest, Madam, _Your faithful Friend_ _and Servant._ [1] _C._ 28. _a._ 1. XXII. _MADAM,_ The Generation of sound, according to your worthy _Authors_ opinion, is as follows: _As Vision,_ says he,[1] _so hearing is Generated by the medium, but not in the same manner; for sight is from pressure, that is, from an endeavour, in which there is no perceptible progression of any of the parts of the medium, but one part urging or thrusting on another, propagateth that action successively to any distance whatsoever; whereas the motion of the medium, by which sound is made, is a stroke; for when we hear, the drum of the Ear, which is the first organ of hearing, is strucken, and the drum being stricken, the_ Pia Mater _is also shaken, and with it the arteries inserted into it, by which the action propagated to the heart it self, by the reaction of the heart a Phantasme is made which we call Sound._ Thus far your _Author_: To which give me leave to reply, that I fear, if the Ear was bound to hear any loud Musick, or another sound a good while, it would soundly be beaten, and grow sore and bruised with so many strokes; but since a pleasant sound would be rendred very unpleasant in this manner, my opinion is, that like as in the Eye, so in the Ear the corporeal sensitive motions do pattern out as many several figures, as sounds are presented to them; but if these motions be irregular, then the figure of the sound in the ear is not perfect according to the original; for if it be, that the motions are tyred with figuring, or the object of sound be too far distant from the sensitive organ, then they move slowly and weakly, not that they are tyred or weak in strength, but with working and repeating one and the same object, and so through love to variety, change from working regularly to move irregularly, so as not to pattern outward objects as they ought, and then there are no such patterns made at all, which we call to be deaf; and sometimes the sensitive motions do not so readily perceive a soft sound near, as a stronger farther off. But to prove it is not the outward object of sound with its striking or pressing motion, nor the medium, that causes this perception of sense, if there be a great solid body, as a wall, or any other partition betwixt two rooms, parting the object and the sensitive organ, so, as the sound is not able to press it, nevertheless the perception will be made; And as for pipes to convey sounds, the perception is more fixt and perfecter in united then in dilated or extended bodies, and then the sensitive motions can make perfecter patterns; for the stronger the objects are, the more perfect are the figures and patterns of the objects, and the more perfect is the perception. But when the sound is quite out of the ear, then the