198 THE FLUIDS. 



developed in the true mucus (probably from the mucosine espe- 

 cially), in accordance with the law specified on page 146. Hence, 

 in case of irritation, congestion, or inflammation of the membrane, 

 these corpuscles increase; since not only mucus is secreted, but 

 (from the consequent transudation or exudation upon the mem- 

 brane) albumen or fibrine (or both) is blended with it. 



Uses. True mucus is merely protective to the parts with which 

 it is brought in contact. Some of its modifications, however as 

 the gastric and intestinal fluids perform an important function in 

 aid of digestion, as will appear (pp. 200 and 201). 



From the relations of the mucous membrane to the true glands, 

 which have been specified, it must follow that all the glandular 

 secretions must contain an admixture with them, to a greater or 

 less extent, of true mucus and mucus-corpuscles. 



Varieties. Three varieties of mucus have already been men- 

 tioned, viz: 



1. The mucus from the nares and bronchial tubes, the large in- 

 testine, and the interior of the uterus. 



2. That from the neck of the uterus. This has an alkaline reac- 

 tion, while that from the vagina is acid. 



3. The mucus in the urine. 



Other varieties still might be added, which differ not only in 

 appearance, but also in the characters of the mucosine they contain. 



Synovia, in its chemical composition, approaches nearer to the 

 mucous than to the serous secretions. Tildanus always fgund mu- 

 cosine in it, as well as albumen. The synovial bursse also contain 

 true mucus rather than synovia, and were by Bichat not inappro- 

 priately termed "bursse mucosse." 



The remaining modifications of mucus, which require a particular 

 description, are the gastric and the intestinal fluids. 



The Gastric Fluid. 



Pure gastric fluid is clear, liquid, colorless or slightly yellowish, 

 of a peculiar feeble smell, a slightly saltish taste, and of a very 

 acid reaction. It is a little heavier than water, and for a long time 

 resists decomposition. No morphological elements belong to it, 

 though the epithelial cells of the gastric follicles (favuli) and their 

 nuclei, and a fine molecular matter, are found floating in it. 



Gastric fluid, when filtered, contains only 1.05 to 1.48 per cent, 

 of solid elements ; of which 63 per cent, are organic, and 37 per 

 cent, are inorganic matters. 



