XIV

INTRODUCTION.

and however our lungs may act on the principles ofthe steam machine, and so operate from naturalcauses, we shall not always breathe.

Men have contrived to break nearly all God's ap-pointments ; but this "It is appointed for all men onceto die" has never been abrogated or defeated yet byany man. And we should always remember, whenwe are about to take medicine, if the Lord will,we shall do this or that with success ; if the Lordwill, I shall get well by this means or someother.

But to return to the breath—If the air be cooland clear it will always have elasticity, as it iscalled ; it will swell and fly back again easily, whenwe receive it into our lungs. But if the air is warmor hot, we should soon find a difficulty to draw ourbreath. This was very sensibly experienced in New-York, New-Jersey and Pennsylvania, in which Iwitnessed it, being in those parts about the 4th ofJuly, 1811 ; and I conclude that a farther degree ofthe warmth of the air, might soon have prevent-ed us from respiring at all.

Such likely was the case in Calcutta, where aclose room being filled with about 160 prisoners, itis said they all died except 18 in about 12 hours.

If the air is any how nearly as warm as the lungs,I cannot see how we should breathe at all : it isnecessary therefore for us to try to breathe good air,if we would wish to live.*

* In South Carolina I was once in company with oldDr. Dillihoo, who was noted for great skill and experi-ence, having travelled into many "parts of the world.In the course of our conversation, I asked him what heconceived the plague to be, which has been so muchtalked of in the world. He readily told me " that itwas his opinion the plague is occasioned by an invisibleinsect. This insect, floating in the air, is taken in with