In its first and second stages this disease is tolerablyainenable to treatment. Wl(Ctlier when the lung has reached the third stage it is still susceptible of repair we cannot tell, because we have no certain sign ? of the commencement or establishment of this third stage during life, although we may guess that it is established if the face has become very pale and corpse-like: if there is the prune-juice or purulent expectoration; and if the disease has lasted for a sufficient iliac to have advanced so far, although it would ire very difficult to state, with any approach to accuracy, what the necessary time is. The average duration of pneumonia may be placed at ten days or a fortnight.
Of the causes of this disease very little need be said. Sometimes no cause can be traced. Very often it is the consequence of exposure to cold, especially when the body was previously heated by exercise; but why such exposure should in one person cause pneutrionia, in a second pleurisy, in a third, pericarditis, and in a fourth, peritonitis, we cannot tell.
The following is a brief outline of the treatment to be adopted, provided the patient was previously strong and healthy: In the first stage, free venesection, tartarized anti mony (one-third of a grain to half a wine-glassful of water every hour, and the dose to be increased to a grain or more hourly, if there is no purging or vomiting, which may often be prevented by the addition of a few drops of laudanum to each dose), and anti phlogistic regimen generally are'of service, Under this system there are often signs of improvement in five or six hours, although sometimes there is no change for the better till 24 hours or more have elapsed. When the disease has reached the second stage, in preference to continuing the antimony we should as speedily as possible get the system gently under the influence of mercury, in the mode recommended in the articles PERI ' CAIIDITIS and PERITONITIS. If there is great depression of the vital powers, as indicated by a feeble and irregular pulse, and tire other ordinary signs of sinking, it will be requi site to administer stimulants, such as wine and carbonate of ammonia, and to feed the patient on beef-tea.
There are few diseases in which it is of greater importance to watch the patient during convalescence than in pneumonia. The convalesence is often rather apparent than real, and, as Dr. Watson truly observes. "a patient can never be pronounced per fectly secure so long as any trace of crepitation remains in the affected lung, and this may often continue long; nay, it not nnfrequently ceases only on the supervention of another more surciy fatal though less rapid disorder, viz., tubercular consumption." PO (tine. Eridanua and Padus), the largest river of Italy, rises in two springs on the a. and a. sides of Monte Viso, one of the Cottian Alps, close to the French frontier, and in let. about 40' north. It flows eastward for upward of 20 m. when, arriving before Saluzzo, it emerges from its rocky defiles and enters upon the plain. From Saluzzo it flows n.n.e. past Turin, and arriving at the town of Chivasso it changes its course toward the e., in which direction it flows to its embouchure in the Adriatic. Upward of 50 m. above its mouth it begins to form its delta, the principal branches being the Po della Maestra on the n., and the Po di Primaro on the south. The unhealthy marsh of the Valli de annumhie extends immediately D. of the Primaro branch. The Po receives from The left time Dora Itiperia, Dora Baltea, Scala, Ticino, Adda, Oglio, and Minch); from the right the Tanaro. Bormida, Trebbia, Taro, Parma, Enza, Seechia, and Palm•). At Turin the Po is about 750 ft. broad; at Pavia, 1050 ft.; at Cremona, 2,650 ft.; and below Polesella, after throwing off the Po di Primaro branch to the its breadth is about 850 feet. It has an entire length of 400 in., is navigable for small barges 60 m. from its source, and drains an area of nearly 40,000 sq. miles.
POA, See MEADOW GRASS.