COLLOID. PSEUDOMUCIN. 625 



Colloid. This name does not designate any particular chemical 

 substance, but is given to the contents of tumors with certain physical 

 properties similar to gelatin jelly. Colloid is found as a pathological 

 product in several organs. 



Colloid is a gelatinous mass, insoluble in water and acetic acid'; it is 

 dissolved by alkalies and gives a liquid which is not precipitated by 

 acetic acid or by acetic acid and potassium ferrocyanide. According to 

 PFANNENSTIEL l such a colloid is designated /3-pseudomucin. Some- 

 times a colloid is found which, when treated with a very dilute alkali, 

 gives a solution similar to a mucin solution. Colloid is very closely 

 related to mucin and is considered by certain investigators as a modified 

 mucin. An ovarial colloid analyzed by PANZER contained 931 p. m. 

 water, 57 p. m. organic substance, and 12 p. m. ash. The elementary 

 composition was C 47.27, H 5.86, N 8.40, S 0.79, P 0.54, and ash 6.43 

 per cent. A colloid found by WURTZ 2 in the lungs contained C 48.09, 

 H 7.47, N 7.00, and 0(+S) 37.44 per cent. Colloids of different origin 

 seem to be of varying composition. 



Metalbumin. This name SCHERER 3 gave to a protein substance 

 found by him in an ovarial fluid. The metalbumin was considered by 

 SCHERER to be an albuminous body, but it belongs to the muein group, 

 and it is for this reason called pseudomudn by HAMMARSTEN.* 



Pseiidomucin. This body, which, like the mucins, gives a reducing 

 substance when boiled with acids, is a mucoid of the following com- 

 position: C 49.75, H 6.98,. N 10.28, S 1.25, 31.74 per cent (HAMMAR- 

 STEN). With water pseudomucin gives a slimy, ropy solution, and it is 

 this substance which gives the fluid contents of the ovarial cysts their 

 typical ropy property. Its solutions do not coagulate on boiling, but 

 only become milky or opalescent. Unlike mucin, pseudomucin solutions 

 are not precipitated by acetic acid. With alcohol they give a coarse 

 flocculent or thready precipitate which is soluble even after having been 

 kept under water or alcohol, for a long time. 



Paralbumin is another substance discovered by SCHERER, which occurs 

 in ovarial liquids, and also in ascitic fluids, with the simultaneous presence 

 of ovarial cysts and rupture of the same. It is therefore only a mixture 

 of pseudomucin with variable amounts of protein, and the reactions of 

 paralbumin are correspondingly variable. 



1 Arch. f. Gynak., 38. 



2 Panzer, Zeitschr. f . physiol. Chem., 28; Wiirtz, see Lebert, Beitr. zur Kenntnis 

 des Gallertkrebses, Virchow's Arch., 4. 



8 Verh. d. physik.-med. Gesellsch. in Wiirzburg, 2, and Sitzungsb.er. der physik.- 

 med. Gesellsch. in Wiirzburg fur 1864-1865; Wiirzburg med. Zeitschr., 7, No. 6. 

 4 Zeitschr. f . physiol. Chem., 6. 



