MUCUS. 75 



It follows, from the preceding observations, that mucus con- 

 tains the following constituents : mucus- corpuscles, epithelium 

 cells, mucin, small quantities of extractive matters and fat, 

 chlorides of sodium and potassium, alkaline lactates, a little 

 carbonate of soda and phosphate of lime, and sometimes a 

 minute quantity of albumen. In order to separate these con- 

 stituents I adopt the following course. 



A known weight of mucus must be washed with distilled 

 water and evaporated to dryness on the water-bath. The re- 

 sidue must be finely triturated and repeatedly extracted with 

 boiling ether in order to remove the fat ; it must then be boiled 

 in spirit of 0-91 as long as any additional matter is dissolved. 

 The spirituous solution must be evaporated to a small syrupy 

 residue, and alcohol of O85 added, in order to precipitate any 

 dissolved mucin, caseous matter, water-extract, and pyin : the 

 alcoholic solution, containing the alcohol- extract and lactates, 

 is also to be evaporated. The portion undissolved by boiling 

 spirit of 0*91, consists of mucin with cells, and traces of albu- 

 men, if the previous qualitative investigation has shown that 

 this substance is present. 



In order to determine the salts, a portion of the dried re- 

 sidue must be submitted to incineration. It is difficult to ob- 

 tain a white ash in consequence of the fusion of the salts. The 

 chlorides may be extracted with spirit; the residue must be 

 then treated with acetic acid, in order to convert the carbonates, 

 which have arisen from the incineration of the alkaline lactates, 

 into acetates, which may be extracted with alcohol. Anything 

 that still remains, is composed of phosphates and perhaps sul- 

 phates, in very minute quantity, together with traces of iron 

 and silica. 



I have analysed mucus both from the nose and lungs, during 

 pulmonary catarrh, but as I cannot regard these cases as illus- 

 trations of normal mucus, I shall defer their consideration for 

 the present. From an analysis of nasal mucus made by 

 Berzelius, it appears that there are in 1000 parts : 



Water ..... 933-7 



Mucin ..... 53*3 



Alcohol- extract and alkaline lactates . . 3*0 



Chlorides of sodium and potassium . . 5-6 



Water-extract with traces of albumen and phosphates 3'5 



Soda, combined with mucus . . . 3'9 



