44 THE MUCIN OF WHITE 



a recent examination of mucin prepared from this same source 

 we have obtained quite different results as regards the content 

 of sulphur, and this fact has led us to make a careful study of 

 the composition of this form of connective-tissue mucin. Our 

 results in the main have afforded a close substantiation of the 

 conclusions arrived at by Loebisch, with the single exception 

 of the sulphur for which we can find no adequate explanation. 

 Further, some additional facts have been found which are 

 perhaps worthy of note. 



The first sample of mucin studied was prepared from the 

 Achilles tendons of oxen by the following method, analogous 

 to the method described by Loebisch: The fresh tendons 

 were freed as carefully as possible from all adherent tissues, 

 then cut into very thin traverse sections with a razor, washed 

 thoroughly with distilled water, frequently renewed for 

 twenty-four hours, in order to remove all blood and soluble 

 albuminous matter, and finally pressed as dry as possible. 

 The resultant material weighed 1200 grams. In order to 

 extract the mucin, the tissue was placed in 2.4 liters of half- 

 saturated lime-water, where it was allowed to remain for 

 forty-eight hours with frequent agitation. At the end of this 

 period the pale-yellowish fluid was strained through a cloth 

 filter and finally filtered through paper. The clear fluid was 

 then treated with an excess of 0.2 per cent hydrochloric acid 

 a little more than a liter by which a heavy flocculent 

 precipitate resulted, quickly settling to the bottom of the 

 cylinder, leaving a nearly clear supernatant fluid. 



The residue of tendon-tissue was again extracted for 

 forty-eight hours with 2.4 liters of half-saturated lime-water, 

 and the resultant solution precipitated with an excess of 

 0.2 per cent hydrochloric acid. The precipitate so formed 

 was nearly as heavy as the first, thus showing that extraction 

 of the mucin by weak lime-water is a slow and gradual process. 



The precipitated mucin, separated from the acid fluid by 

 subsidence and decantation of the supernatant liquid, was 

 washed thoroughly with 0.2 per cent hydrochloric acid, whip- 

 ping up the precipitate with the fluid and then allowing it to 



