i 4 4 SCIENCE PROGRESS. 



The method Kossel 1 recommends for the preparation of 

 protamine is to thoroughly extract the dried spermatozoa 

 heads, which have been previously freed from fat, etc., by 

 extraction with alcohol and ether, with i per cent, sulphuric 

 acid. This is then filtered and added to three times its 

 volume of alcohol, when a precipitate of protamine sulphate 

 is formed and can be readily purified. From analysis of 

 the pure salt he arrives at the formula C l6 H 3I N 9 3 for the 

 base. He criticises Miescher's formula, showing that it 

 cannot be correct because it does not satisfy the necessary 

 condition that the sum of the valencies should be an even 

 number, and points out that if another H atom be added to 

 Miescher's formula, then the two only differ by one molecule 

 of water. For the protamine obtained from salmon sperm 

 he suggests the name salmine, and for a similar protamine 

 obtained from the spermatozoa of the sturgeon, the name 

 sturine. If sturine be decomposed by boiling it for eight 

 hours with 30 percent, sulphuric acid and then the sulphuric 

 acid be removed, an alkaline fluid is left which gives a pre- 

 cipitate with mercuric chloride, leaving further bases still in 

 solution. The mercuric precipitate is a compound of a new 

 base which Kossel terms histidine having a formulaC 6 H g N 3 2 , 

 which is readily soluble in water, but crystallises out when 

 an equal volume of alcohol is added to its solution. It is 

 quite insoluble in ether. Histidine has also been found by 

 Hedin-' among the decomposition products from casein, 

 egg-white and vitellin. From the filtrate from the histidine 

 precipitate Kossel also prepared arginine, thus confirming 

 and extending the work of Miescher upon salmine. Kossel 

 further examined the decomposition products of sturine for 

 amido-acids, but found that they were only present in quite 

 minimal amounts, so that practically the whole of the 

 nitrogen of the protamines is present in the form of bases. 

 Balke 3 showed that protamine resembled the alloxuric 

 bodies in that it gave a white precipitate with cuprous 



1 Kossel : Zeitschr. f. physiol. Chem., Bd. 22, S. 178, 1896; and 

 .Stzber. d. Preuss. Ak. d. Wiss., Bd. 18, S. 403, 1896. 



2 Hedin : Ztschr. f. physiol. Chem., Bd. 22, S. 191, 1896. 



3 Balke : Journ. f. prakt. Chem., Bd. 47, S. 537, 1893. 



