374 MUCUS. 



intestinal canal, and in this manner the intestinal juice and mucus 

 have frequently been identified with certainty. But the difference 

 between the mucus and the glandular secretion effused upon 

 the intestinal mucous membrane, ought to be strictly kept in view. 

 We have already spoken (at p. 118) of the intestinal juice. 



The free acids frequently found in the mucus are included 

 amongst the extractive substances. Andral* maintains that true, 

 pure mucus is always acid in a normal state ; but although this 

 assertion may be true, it has not been proved, nor indeed would 

 it be very easy to do so ; for as we are not acquainted with any 

 entirely pure mucus, which may possibly be wholly free from any 

 reaction on vegetable colours, we may assert, in reference to every 

 mucus which exhibits an alkaline reaction, that this property may 

 be owing to certain admixtures, consisting either of pure transu- 

 dations from the blood or of special glandular secretions. As may 

 be readily conjectured, no careful investigation has as yet been 

 made in reference to the nature of the free acid which occurs, 

 amongst other instances, in the secretions of the mucous mem- 

 branes of the mouth and the urinary bladder. 



In considering the quantity of the alkalies contained in mucus, 

 we must especially bear in mind that no inconsiderable portion of 

 the soda is combined with true mucin, as was observed by Berze- 

 liusf in the secretion from the mucous membrane of the nose, and 

 by Scherer in the abnormally generated mucus above referred to. 

 Nasse also found alkaline carbonates together with carbonate of 

 lime in the ash of the normal nasal secretion. 



Mucus is very rich in alkaline chlorides, of which Berzelius 

 found 0'56 in fresh nasal mucus, and Nasse 13-g- in the dry residue 

 of similar mucus, which, however, contained no cells. 



Nasse found some alkaline sulphates and phosphates, together 

 with earthy phosphates, in the ash. 



Berzelius found 6*63^ and Nasse 4*44 S-g- of solid constituents 

 in the nasal mucus, and Scherer 11 '299% in the above described 

 abnormal mucus. The latter observer likewise found 7'6-g- of ash 

 in 100 parts of the solid residue. 



Unfortunately, however, no attention has been paid in these 

 analyses of the normal mucus to the relation existing between the 

 potash and the soda. Yet the establishment of this relation is not 

 wholly devoid of importance in the solution of the question, whether 

 the blood-corpuscles take part in the preparation of the mucus as 

 they do in that of most other secretions, or whether the mucus is 



* Compt. rend. T. 26, p. 650657. 



t Lehr. d. Chem. 4 Aufl. Bd. 9, S. 531. 



