692 ACUTE INFECTIOUS DISEASES. 



cause some change in the tissues that impedes absorption of the 

 germs. It is said that acclimated persons are not troubled by 

 mosquitoes, which are usually very plentiful in yellow-fever re- 

 gions. 



ANATOMICAL APPEARANCES. Rigor mortis is early and decided. 

 The skin is more or less jaundiced. The heart is often pale and 

 relaxed ; its muscles may have undergone fatty degeneration. The 

 greatest changes are seen in the abdomen ; there is acute catarrh 

 of the mucous membrane of the alimentary canal ; rarely there 

 may be ulcers in the stomach, and there is usually more or less 

 dark blood (black vomit is blood mixed with the fluids of the 

 stomach). The liver is but little changed in size, but is of uneven 

 yellow color (more marked in the left lobe), and its cells are filled 

 with fat ; it looks like the fatty liver of drunkards. The spleen 

 is not especially changed. The cortical substance of the kidneys 

 is often swollen, and there are signs of inflammation in all parts 

 of them. 



SYMPTOMS AND COURSE. The period of incubation is not set- 

 tled, but probably is from a few hours to three days. The first 

 symptoms are chilliness alternating with fever, or perhaps a severe 

 chill, great restlessness, red face and eyes, headache (" the most 

 characteristic symptom of the disease is the peculiar pain in the 

 forehead and eyeballs, with the drunken appearance of the eye "), 

 pain in the joints, fever (102 Fahr. or more), frequent respira- 

 tion, and frequent pulse. Severe cases sometimes have a cadav- 

 eric odor early in the disease. The tongue is coated and swol- 

 len, the pharynx reddened ; the gums swell and bleed readily. 

 The epigastrium is very sensitive, and there is usually vomiting. 

 The kidneys are affected, and albuminuria is common ; it is said 

 that if the albumen disappears gradually, it is a favorable sign, 

 while its continuance or increase is ominous. The symptoms in- 

 crease till the second or third day, the temperature rising to 

 about 105. Then there may be jaundice of the skin and conjunc- 

 tiva ; the urine contains bile ; the faeces retain their color, show- 

 ing that the jaundice is haematogenous. There is frequent haemor- 

 rhage from the nose, or more rarely from the stomach ; the latter 

 is of evil import. 



After increasing in severity for about two or three days, the 

 symptoms subside ; the temperature may fall to normal in twelve 

 hours, but does not usually go below 100 ; the patient may feel so 

 much better as to think he is well ; but the nausea and sensitiveness 

 of the epigastrium remain. This stage of remission may last one or 



