MUCUS. 133 



Thus the mucus furnished by the nasal and bronchitic 

 mucous membranes, and which may be called nasal and 

 bronchitic mucus, as also that of the digestive tube, from the 

 pyloric orifice of the stomach unto near the termination of 

 the rectum (the caecum alone excepted), of the urethra, pro- 

 static gland, vesiculse seminales and the uterus, belongs to the 

 first division of mucus, viz. that which is secreted by the 

 true mucous membranes. (See Plate XII. fig. 3.) 



The mucus of the vagina presents the best example of the 

 mucus of the second class, which is secreted by the false mu- 

 cous membranes. (See Plate XII. fig. 1.) 



Lastly. The mucus of the mouth, rectum and bladder, 

 appertain to the third description of mucus, and which is 

 supplied by the mixed mucous membranes. (See Plate XII. 



fig- 2 -) 



Vaginal and Uterine Leucorrhea. 



One practical result arising from the discrimination of 

 mucus into different kinds may here be alluded to ; thus by 

 means of the difference in the microscopic characters of the 

 mucus secreted by the uterus and that furnished by the 

 vagina, it is in our power to decide in cases of leucorrheal 

 discharge, whether the affection has its seat in the mucous 

 membrane of the uterus or in that of the vagina. The mucous 

 membrane of the uterus, as we have seen, belongs to the class 

 of true mucous membranes, that of the vagina, on the con- 

 trary, to the false mucous membranes ; now if the leucorrhea 

 be uterine, the discharge will present the globules charac- 

 teristic of the secretion produced by the class of true mu- 

 cous membranes ; if, on the other hand, it be vaginal, the 

 mucus will contain the epithelial scales which belong to the 

 mucus of false mucous membranes ; moreover, the former 

 mucus will be alkaline, and the latter acid. 



Effect of Acid Mucus on the Teeth. 



The degree of acidity presented by the mucus of the mouth 

 varies considerably, according to the relative proportions of 



M 2 



