I/o Proceedings Columbia Biochemical Association [Sept. 



yields a prodtict which (when free from sodium chlorid) is water- 

 soluble, gives all the qualitative histon tests, and contains less 

 nitrogen than the "ammonia precipitate" from the other fraction; 

 the " ammonia precipitate " being water-insohtble and appar- 

 ently a very different stibstance. Finally, when the " sodium 

 chlorid precipitate " of histon is dissolved in vvater, and the aqueous 

 Solution is treated with a few drops of ammonium hydroxid Solu- 

 tion, a precipitate is produced which is insoluble in water. Quanti- 

 tative studies now under way show marked differences in the nitro- 

 gen content of the two products. 



The results suggest that " histon " as commonly prepared is an 

 adsorption product or a salt, rather than a simple protein. 



The following method is suggested as a means of obtaining 

 water-soluble histon from thymus : Mince f resh thymus glands and 

 extract the hash with distilled water for 24 hours (best in the cold), 

 Precipitate the aqueous extract with acetic acid Solution and ex- 

 tract the precipitate with 0.8 per cent. hydrochloric acid Solution 

 (after Lilienfeld) ; or add sufficient calcium chlorid to the aqueous 

 extract to make its content of that substance 0.2 per cent. and 

 extract the precipitate with 0.8 per cent. hydrochloric acid Solution 

 (after Huiskamp) ; or add sufficient hydrochloric acid to the aqueous 

 extract to make its content of the acid 0.8 per cent. and let stand 

 24 hours (after Kossei and Kutscher). Filter off the hydrochloric 

 acid extract, and either remove the free acid or precipitate the 

 histon directly by Saturation with sodium chlorid. Remove ad- 

 mixed sodium chlorid by dialysis. Filter the resultant salt-free 

 Solution and evaporate it to dryness at 45° C. This material, 

 ground to a powder, may be heated to 105° C. without loss of 

 water-solubility. 



21. The influenae of proteases on the swelling of Collagen 

 and fibrin particles in alkalin and acid media containing a bio- 

 logical electrolyte. Frank R. Elder and William J. Gies. 

 (Published in full in the June issue of the Biochemical 

 Bulletin. )^^ 



22. A convenient form of apparatus for demonstrations of 

 osmotic pressure exerted by lipins. William J. Gies. The 



" Eider and Gies : Biochemical Bulletin, 1912, i, pp. 540-545. 



