59 



dissolved in the bile, is precipitated by the acid in 

 the chyme, when the bile is decompounded during 

 digestion. The mucus of the gall bladder, if it 

 had the properties of that in the nose and trachea, 

 would remain in solution in the chyle, and, there- 

 by, be le>ss useful in the animal oeconomy. Se- 

 veral Authors mention an animal mucus, as a sub- 

 stance distinct from the mucus of the membranes, 

 and supposed to be found in the fluids of the ani- 

 mal body. I can only say, that in all my experi- 

 ments, I have never found any matter, to which 

 this name could be applied, or which agreed, satis- 

 factorily, with the character of those substances, 

 which HATCHETT, BOSTOCK, JORDAN, and 

 others, have designated by that name. It ap- 

 pears probable to me, that with most of them, 

 mucus has been a common name for matters, 

 which could not be distinctly specified. The cele- 

 brated FOURCROY, a little before his death, left 

 us a treatise on mucus, in the sense in which I 

 have here used the term ; but this treatise was not 

 occasioned by any direct investigation, but was a 

 mere result of scattered observations, whereby he 

 fell into an error (to him not very uncommon) of 

 drawing general and extensive conclusions from 

 very uncertain, and sometimes incorrect observa- 

 tions ; and with these ingenious and interesting 



