112 Some Protein Compounds [Sept. 



histons and protamins, with the acid-reacting proteins eiiumerated 



above. 



In developing the latter part of this plan certain anomalies arose 

 in connection with the preparation of thymus histon, which led to 

 a collateral investigation of histons. The results of the latter 

 studies will be embodied in a future paper. (See page 169.) 



IL EXPERIMENTAL 



I. Salts of various proteins with organic bases. 'Ä. Mor- 

 phin MUCOiD. Purification of the materials. The first step in the 

 preparation of a typical product was the removal of free alkali f rom 

 the base — and free acid from the protein. Chemically pure, pul- 

 verized, morphin was washed with distilled water until the wash- 

 ings were entirely neutral to litmus. Tendo-mucoid was prepared 

 after the manner of Cutter and Gies^ but dehydration with alcohol 

 and ether was omitted. The dry scales w^ere soaked in distilled 

 water until they softened. The protein was then washed with dis- 

 tilled water until the washings were entirely neutral to litmus. 



Union of base and protein. The base and the protein were then 

 triturated together in a mortar, a very little water being added to 

 ensure an intimate mixture. A mechanical excess of the base was 

 used in every case. Evidence of chemical action was seen in the 

 peculiarly viscid, smeary character of the mixture. Mucoid and 

 w-ater give a thick, milky mixture, but it is not viscid or smeary. 

 The mixture w^as finally treated with sufficient water in excess to 

 dissolve the product. The viscid liquid was filtered through a wet, 

 fluted, hardened, filter paper, but the first portions of iiltrate were 

 returned to the paper until a clear opalescent liquid appeared. This 

 filtrate was neutral to litmus. 



Purification of the product. The filtrate, preserved with tol- 

 uene, was subjected to continuous dialysis in a parchment bag, im- 

 mersed in frequently renewed distilled water, until the dialysate, 

 even when concentrated to a very small volume at 40° C, gave no 

 test for the base (morphin). The contents of the bag were then 

 evaporated to dryness at 40° C, toluene being used and frequently 

 renewed during the process. The resultant dry produot was then 



' Cutter and Gies : Amer. Journ. PhysioL, 1902, vi, pp. 155-6. 



