This part of the paper contains an inquiry into the action of a vibrating body upon a linear elastic series, as representative of the action of a sound-emitting substance upon the air.

It results that when one end of a linear elastic series is attached to an oscillating substance, all the internal oscillations of which the system is capable when one end of it is fixed, are called into existence; the number of these being equal to the number of the elements in the system, and their periodic times being mutually incommensurable; and that to these is added another, isochronous and synchronous with that of the oscillating substance.