ALBUMINOIDS. 



Ill 



Solutions of these bases in water are alkaline and have the property 

 of giving precipitates with ammoniac al solutions of proteins or primary 

 proteoses, but the researches of HUNTER x show that these precipitates 

 are not histones, as generally considered. The salts with mineral acids 

 are soluble in water, but insoluble in alcohol and ether. They are more 

 or less readily precipitated by neutral salts (NaCl). Among the salts 

 of the protamines, the sulphate, picrate, and the double-platinum chloride 

 are the most important, and are used in the preparation of the protamines. 

 The protamines are, like the proteins, levogyrate. They give thebiuret 

 test beautifully, but with the exception of cyclopterine and /?-cyprinine 

 do not give MILLON'S reaction. The protamine salts are precipitated 

 in neutral or even faintly alkaline solutions by phosphotungstic acid, 

 picric acid, chromic acid, and alkali ferrocyanides. 



The protamines are prepared, according bo KOSSEL, by extracting the 

 heads of the spermatozoa, which have previously been extracted with 

 alcohol and ether, with dilute sulphuric acid (1-2 per cent), filtering, and 

 precipitating with 4 vols. of alcohol. The sulphate may be purified by 

 repeated solution in water and precipitation with alcohol, and if neces- 

 sary, conversion into the picrate. For more details see the works of 

 KOSSEL and MALENUCK. The double-platinum salt is best suited for 

 analysis and can be obtained, according to GOTO, by precipitating the 

 methyl-alcohol solution of the protamine hydrochloride with platinum 

 chloride. MIESCHER also precipitates the base as a double-platinum salt. 



B. Albuminoids or Albumoids. 



Under this name we collect into a special group all those protein 

 bodies which cannot be placed in either of the other groups. Most and 

 best studied of the bodies belonging to this group are important con- 

 stituents of the animal skeleton or the cutaneous structure. Some are 

 hardened secretions, and all occur as a rule in an insoluble state in the 

 organism, and they are distinguished in most cases by a pronounced 



Zeitschr. f. physiol. Chem., 53. 



