1050 LIQUIDS OF SEROUS AND MUCOUS SURFACES. 



SECTION V. 



LIQUIDS OF SEROUS AND MUCOUS SURFACES AND PURULENT 



MATTER. 



Lymph. The liquid which moistens the surface of cellular 

 membrane is called lymph ; it is chiefly water, but contains 

 a sensible quantity of common salt and of albumen, and when 

 concentrated a trace of alkali sufficient to affect test-paper. 



The liquid secreted by serous membranes, such as the 

 pericardium, pleura and peritoneum, resembles lymph, but 

 contains so much as 7 or 8 per cent of albumen and salts, and 

 is distinctly alkaline, from the presence of carbonate or albu- 

 minate of soda. The liquor amnios and fluid of hydatides are 

 of the same composition. The water of dropsy contains in 

 addition urea, and cholesterin suspended in fine plates. All 

 these liquids become turbid or coagulate, when boiled, or upon 

 the addition of nitric acid to them. 



Mucus. This is the liquid secreted by mucous surfaces, 

 such as the nostrils. The mucus of the nostrils usually 

 contains about 93 per cent of water, 5 per cent of mucus, with 

 a trace of albumen and the usual salts. Mucus is insoluble in 

 water, but imbibes it and swells up, so as to form a ropy liquid, 

 as if it were dissolved. It shrinks up in concentrated acetic 

 acid, and is not dissolved. When dry it is yellow. It dissolves 

 in caustic alkali, and forms a thin liquid. Mucus contains 

 nitrogen, but its composition is otherwise quite unknown. 



Pus. The matter secreted by an inflamed and ulcerated 

 surface is named pus. From a healing sore it is a yellowish 

 white liquid, of the consistence of cream, which consists of 

 round opaque globules floating in a transparent liquid. It is 

 insoluble in water, but maybe diffused through it; on standing, 

 the globules fall as a yellow sediment, and the supernatant 

 liquid becomes clear and colourless. 



. Pus contains about 86 per cent of water, and 1 4 per cent of 

 solid matter. It is coagulated by heat and by alcohol. There 

 have been found, by analysis, in pus, two albuminous principles, 

 several fatty bodies besides cholesterin, with the usual salts 

 and undetermined extractive matters. 



The matter of the corpuscles of pus considerably resembles 



