ACUTE INFECTIOUS DISEASES. 



a state of atelectasis, from collections of secretion or swelling of the 

 mucous membrane of the bronchi leading to them having rendered the 

 passage impervious. In some cases also we find lobular and lobar 

 pneumonia, not affecting the dependent part of the lung, and not de- 

 pending on hypostasis, even at the height of the disease, although it 

 is more common after it has run its course. The bronchial glands are 

 swollen, vascular, and occasionally have a medullary appearance, such 

 as we shall describe for the mesenteric glands. The heart is usually 

 relaxed, its muscles pale, sometimes of a dirty-red color ; the endocar- 

 dium and lining membrane of the vessels are infiltrated, red, and dis- 

 colored. The spleen is greatly enlarged, occasionally twice, or even 

 six times its normal size ; its capsule is tense, its parenchyma pulpy, 

 and of a dark-violet or blackish-red color. In rare cases we find the 

 capsule of the spleen ruptured, and blood poured through the rupture 

 into the peritoneal sac. In the great curvature of the stomach, some- 

 times only the large vessels are distended, sometimes the mucous mem- 

 brane appears dark red, from injection of the finer vessels, and relaxed 

 from infiltration after death. The most important changes occur in 

 the small intestine ; to these ileotyphus owes its name. Rokitansky, 

 on whose unsurpassed description of the "typhous affection of the 

 mucous membrane of the ileum" we base our description, divides it into 

 four stages. In the first or congestive stage, the mucous membrane 

 of the small intestine is the seat of great hypersemia. It appears 

 swollen, relaxed, cloudy, covered with mucous and epithelial masses. 

 This condition extends over all the membrane of the intestine, it is 

 true, but it is most marked in the lower part, near the valvula Bauhini. 

 The mesenteric glands are moderately swollen, soft, vascular, and dark 

 colored. In the second stage, or that of typhous infiltration, the gen- 

 eral redness and swelling of the mucous membrane increase, and con- 

 centrate on the parts around the solitary and Peyer's glands in the 

 lower part of the ileum. In these tissues there are very peculiar 

 changes, which are pathognomonic of typhus. More or less of the 

 glands, and parts around them, swell so as to rise half a line or a line 

 above the surrounding mucous membrane. These prominences are 

 rather hard, and show through the mucous membrane with a gray or 

 yellowish-red color; they have flat or steep edges; they are seated 

 firmly on the muscular coat, and are intimately connected with the 

 mucous membrane covering them. The size of the swollen solitary 

 glands varies from that of a millet-seed to that of a pea. Peter's 

 patches, on the contrary, form patches from the size of a silver gros- 

 chen to that of a dollar ; they are generally oval in shape, and in the 

 vicinity of the valve they usually coalesce, so that at this point they 

 often cover a strip of intestine several inches long. On the cut surface 



