120 Some Protein Compounds [Sept. 



{d) The precipitates obtained in {h) and (c) failed, in this first 

 set of tests, to dissolve in water and the washings gave no hydro- 

 chloric acid or ammonia precipitate. The precipitates dissolved in 

 0.05 per Cent, sodium carbonate Solution and the filtrates gave both 

 the ammonia and hydrochloric acid tests. 



{e) Histon hydrochlorid Solution was not precipitated by alcohol 

 even when sodium chlorid was present. Alcohol also failed to pre- 

 cipitate potassium mucoid Solution but did so in the presence of a 

 trace of sodium chlorid. 



These results Warrant the inference that the sodium carbonate 

 acted as a solvent rather than as a dissociant. They also indicate 

 that precipitation by alcohol in the presence of salt served to dif- 

 ferentiate the histon mucoid from the histon hydrochlorid, and that 

 our product was a Compound and not a mixture. 



A Solution of histon hydrochlorid was tested with an excess of 

 alcohol in the absence of salt. A similar Solution of potassium 

 mucoid was made. When these two clear Solutions were mixed a 

 precipitate of histon mucoid formed at once. This histon mucoid 

 was then dissolved in 0.05 per cent. sodium carbonate Solution and 

 the filtered Solution precipitated with alcohol in the presence of a 

 little salt. This precipitate, unlike that above (d), dissolved readily 

 in zvater. The water-solution gave both the ammonia precipitate 

 and the hydrochloric acid precipitate. This and similar results indi- 

 cated the formation of a soluble histon mucoid Compound. 



Finally a new histon mucoid product w^as made by the original 

 method. This product was washed free from excesses of both his- 

 ton hydrochlorid and potassium mucoid, as before, and then treated 

 as f ollows : 



A portion was macerated in a mortar with o.i per cent. hydro- 

 chloric acid Solution and a second portion in another mortar with 

 0.1 per cent. potassium hydroxid Solution. These liquids were fil- 

 tered. The acid filtrate gave a precipitate with ammonia but not 

 with hydrochloric acid. The alkali filtrate gave a heavy precipitate 

 with hydrochloric acid but none with ammonia. 



These results suggest that mixtures of (a) histon hydrochlorid 

 and potassium mucoid Solutions yield a precipitate of histon 

 mucoid; (&) pure histon mucoid and o.i per cent. hydrochloric acid 



