540 CHEMISTRY OF THE PROTEIDS . CHAP. 



Otori obtained by acting on pseudo-mucin with boiling mineral acids 

 have already been tabulated in the introduction (p. 534). 



6. Para-Mucin 



A variety of pseudo-mucin, first described by Drechsel and 

 Mitjukoff, 1 and later by Panzer,' 2 Leathes, 3 and Steudel, 4 is the so- 

 called para-mucin. Occasionally one finds in all the ovarial cysts, 

 or in some of the cysts of the multilocular tumour, not a fluid, but a 

 trembling jelly, to which Mitjukoff first gave the name of para-mucin. 

 It is insoluble in water, shrinks on the addition of acids, is changed 

 by acid absolute alcohol into a fine, not hygroscopic powder, which is 

 converted again into a jelly on being moistened with a little alkali- 

 solution. On the addition of greater quantities of potassium or 

 sodium hydrate, para-mucin dissolves into a slimy solution, which gives 

 the ordinary mucin-reactions : it is not coagulated by being boiled, 

 and is not precipitated by ferrocyanic acid, although a slight turbidity, 

 depending probably on traces of albumin, may show itself. Tannin, 

 lead-acetate, etc., cause a precipitate, as do also acetic acid and mineral 

 acids. In this last feature para-mucin resembles the true mucins and 

 differs from pseudo-mucin. Excess of mineral acids renders the 

 precipitate soluble. 



Amongst the dissociation -products Mitjukoff found lysin and 

 arginin, and at least 12*5 per cent of a reducing substance, which was 

 liberated by boiling with acids; Steudel obtained about 12 percent 

 of the latter. Glucosamin occurs in para-mucins as it does in other 

 gly co-pro teids, as a more complex compound. 



In certain cystomata, in addition to pseudo-mucin, are also found 

 considerable quantities of albumin, essentially serum - albumin ; this 

 mixture corresponds to Scherer's par-albumin and, as Hammarsten 

 has shown, resembles both in composition and in reactions, a 

 mixture consisting of albumin and pseudo-mucin. 



A substance closely resembling pseudo-mucin, but containing only 

 45 '74 per cent carbon and 5'68 per cent of nitrogen, Hammarsten 5 

 once found in a " ganglion " of unknown origin in the leg of a man. 



1 Kath. Mitjukoff, Dissertation, Bern, and in Arch.f. Gyn&k. 49. No. 2 (1895). 



2 Th. Panzer, Zeitschr.f. physiol. Chem. 28. 363 (1899). 



3 J. B. Leathes, Arch.f. experim. Path. u. Pharmak. 43. 245 (1899). 



4 H. Steudel, Zeitschr.f . physiol. Chem. 34. 353 (1901). 



5 0. Hammarsten abstract in Maly's Jahresber. fur Tierchtmie, 22. 561 (1892). 



