Chap. 3. Of Peripneumonia, or Inflamation of the Lungs.
PEripneumonia hath the same essence with a Pleurisie, and is distinguished only by the part affe∣cted, because that is the inflamation of the Lungs, and this of the Membrane that compasseth the Ribs. They differ somwhat in the matter, for a Pleurisie comes often of Choller, but a Perip∣neumonia of Flegm; although all humors (as we said of a Pleurisie) may produce this disease, I mean humors which are like blood, and make up the mass of it. For as thick humors do hardly pe∣netrate the thick Membrane called Pleura, but thin and Chollerick easily; so on the other side, thick flegmatick humors do easily go to the soft and thin substance of the Lungs, and stick close thereto; but thin and Chollerick humors do easily pass by. But this hindereth not, but the Chollerick blood may somtimes cause the Inflamation of the Lungs, as Hippocrates 1. de morbis, describeth the Ery∣sipelas, or Chollerick tumor of the Lungs, which comes from Chollerick blood thrown into the Lungs from the right Ventricle of the Heart by the Arterial Vein. But an oedematous Inflamation comes from flegmatick blood falling upon the Lungs by way of defluxion from the Head. But only excrementitious flegm, falling as a Catarrh from the Brain, can make a Peripneumonia, because it putrifieth in the Lungs, and attracteth blood, by the mixture whereof there is an Inflamation, and this often happeneth in old folk. Mesue saith that this Peripneumonia comes rather of Choller, be∣cause the Lungs are nourished with Chollerick blood which cometh in great plenty to them by the Arterial Vein. To whom we answer, that fresh, thin, and steeming blood made in the right Ventri∣cle of the Heart is carried into the Lungs, which by reason of its purity, is easily governed by Nature, and is sent by the Venal Artery to the left Ventricle of the Heart, and it seldom is altered from its Natural condition, which useth to make a Peripneumonia. But contrarily, a defluxion from the Head cutting through the large passages into the Bronchia of the Lungs, if it there putrifie, will draw blood unto it, and make a Peripneumonia.
This Peripneumonia is somtimes alone without another disease, somtimes it followeth other dis∣eases, as Squinzy or Pleurisie. Galen in Com. 11. Sect. 7. Aphor. teacheth that a Peripneumonia doth follow a Pleurisie two waies: Either when a Pleurisie is turned into a Peripneumonia, or when an inflamation of the Lungs followeth a Pleurisie. This transmutation is when the former disease ceaseth, and the other comes; but it comes upon it when it is white, the former remaineth.
Therefore the immediate internal cause of a Peripneumonia is blood, often flegmatick, seldom chollerick, and most seldom melanchollick, Which either comes from the whol body being pletho∣rick, or cachochymical, that is, full, or of evil habit; or from some part which is replete or di∣stempered.
The External Causes of Peripneumonia and Pleurisie are the same; namely whatsoever defluxi∣on can come to those parts: the chief whereof are: First great exercise and violent motion of the Body, especially after long rest, and high feeding. For then the humors abounding from high diet, and kept in by long rest, by exercise are dispersed, attenuated, and heated, and are after sent to the weaker parts, most fit to receive them, among which the Breast and Lungs are chief, because by strong exercise, there is caused great and often breathing, and so they become wearied, and the sub∣stance of the Lungs being soft and loose can easily receive the humors coming to them.
Secondly, Among the external Causes the cold and Northernly Air is reckoned, when it comes suddenly after a Southern and warm; for the pores are opened by warm Air, and the humors are more fluid, which by the cold Air coming after, are compressed, and the humors sent to the weak parts.
Lastly, From Hipp. lib. of Air, Places, and Waters, the drinking of standing Pools and Lakes, begets the Peripneumonia; for saith the Divine old man, we observe diseases of the Lungs to be most in Marshy Countries.