MUCUS. 53 



sistence by the addition of a small quantity of water. It is 

 coagulated by acetic acid and by a small quantity of the 

 strong mineral acids, being redissolved in an excess of the 

 latter. It is also coagulated by strong alcohol, forming a 

 fibrinous clot soluble in hot and cold water. Mucosine may 

 be readily isolated by adding water to a specimen of nor- 

 mal mucus, filtering, and precipitating with an excess of 

 alcohol. If this precipitate, after having been dried, be ex- 

 posed to water, it assumes the viscid consistence peculiar 

 to mucosine. This property serves to distinguish it from 

 albumen and other organic nitrogenized principles. 



Nasal Mucus. The nasal mucus, being subject to so 

 many changes from irritation of the Schneiderian membrane, 

 presents considerable variation in its appearance and compo- 

 sition. Under perfectly normal conditions, it is very viscid, 

 clear or slightly opaque and grayish, and strongly alkaline. 

 It always contains more or less columnar epithelium. In its 

 behavior to various reagents, it presents the characteristics 

 which we have ascribed to the secretions of the mucous 

 membranes generally. The following is the composition of 

 the normal secretion : 



Composition of Nasal Mucus? 



Water 933'00 to 947'00 



Mucosine (with a trace of albumen ? ) 53'30 " 54'80 



Lactate of soda (?) 1-00 " 5'00 



Organic crystalline principles 2*00 " T05 



Fatty matters and cholesterine not estimated 5 '01 



Chlorides of sodium and potassium 5 '60 to 5*09 



Calcareous and alkaline phosphates 3'50 " 2'00 



Sulphate and carbonate of soda : 90 not estimated. 



Bronchial and Pulmonary Mucus. This is the secre- 

 tion of the general mucous surface of the larynx and bron- 

 chial tubes, mixed with the products of the glands situated 

 in the substance of these membranes and in the submucous 



1 ROBIN, Le?ons sur les humeurs, Paris, 1867, p. 450. 



