INTRODUCTION.

CHAPTER I.

The Doctrine of Respiration I think somewhat im-portant, because it will show the necessity of breath-ing good air.

An Indian, it is storied, when asked what hethought was the reason of the ebbing and flowingof the tide, made answer : '' You know there is agreat deal of odds between a big creature and a lit-tle one ; a horse draws his breath a great deal slowerthan a mouse: the world is a big creature—he drawshis breath only twice in the day and night; thatmakes the tide.

Now my intention is not to enquire about the tide,but to state to you how I think we draw our breath,or respire.

I consider the lungs to be the pump of life.—Fresh, cool air, drawn into the lungs or lights, im-mediately is rarefied by their heat, and is directlyforced back again, in the same way that it was takenin; then we are by some means (voluntary or invo-luntary) disposed to fill ourselves again with freshgood air. Thus our respiration is carried on by thegreat author of our existence, to whose praise weought ever to be ready to say :

" His spirit moves our heaving lungs," Or we should breathe no more,"