A CONTRIBUTION TO THE KNOWLEDGE OF ARGININ. 3 



from fat and other impurities ; then a dilute solution of caustic 

 potash (0.2-0 4%) was added, and the whole was well stirred,' 

 and after 24 hours the upper portion of the solution, was slowly 

 decanted. The remaining portion was once more extracted 

 with potash solution and the upper portion decanted. This opera- 

 tion was repeated 3 times and the residue filterd with fine cloth, 

 and the filtrate was mixed with the decanted solution. On 

 neutralizing the potash extract thus obtained with dilute acetic 

 acid, a brown flocculent precipitate was produced in a large 

 quantity. This precipitate was first washed by decantation and 

 afterwards collected on a filter, where it was again washed with 

 water. The crude proteids thus obtained, were once more 

 dissolved in the potash solution and rcprecipitated with acetic 

 acid, collected on a filter, washed with water, dilute alcohol, 

 absolute alcohol and ether and dried over sulphuric acid. The 

 crude proteids prepared in this way still contained some impuri- 

 ties of a reddish brown colour, which could be removed with 

 difficult)-. The dry proteids yielded nitrogen, therefore if 



must have been still mixed with a considerable quantity of 

 non-nitrogenous substances. The impure proteids were finely 

 powdered and boiled with 20% hydrochloric acid (sp. gr 1.10) 

 and some stannous chloride in a reflux cooler, at first very 

 gently and afterwards directly over the flame. After 30 hours 

 boiling, they were cooled and filtered. The filtrate was diluted 

 with about 5 times its own bulk of water, the dissolved tin was 

 precipitated with sulphuretted hydrogen, and the solution filter- 

 ed once more. The filtrate was evaporated to a small volume to 

 expell the greater part of hydrochloric acid, and then diluted 



1. 10 g. air dry = 8.28 g. dry sample yielded : — 



a) Soluble in 10% NaCl, and coagulable by boiling 0.00093 S N. 



b) „ „ „ „ not „ „ .„ ...o.oi4i4gN. 



2. 10 g. air dry = 8.28 g. dry sample yielded : — 



a) Soluble in 10% NaCl, and coagulable by boiling 0.001 12 g X. 



t>) „ „ „ „ not „ „ , 0.0141 gN. 



Wc have on the average 0.18^0 nitrogen in the form of proteids soluble in 



10% sodium chloride. 

 As the fat free sample contains i.8j\J nitrogen so we sec that nearly 10% 



of the total proteids is soluble in 10 % sodium chloride. 

 Therefore wc must conclude that the greater part of the bases come from the 

 proteids, which are not soluble in sodium chloride. 



