FORMATION OF ASPARAGINE IN PLANTS. 



425 



The solutions were once renewed. The plants were very 

 healthy, and rapid growth was observed : especially was this the 

 case with the ammonium chloride plants. The analysis, for which 

 the entire plants were used, yielded the following results for 100 

 parts of dry matter : — 



Table XXIII. 



Plants treated with 





Original 



Control 



Ammonium 



Ammonium 



Urea 



Sodium 





plants 



plants 



chloride 



carbonate 





nitrate 



Total nitrogen 



3-72 



3-73 



448 



4-5i 



4-63 



4.60 



Albuminoid nitrogen 



1.98 



1 .81 



1.64 



i-73 



1.96 



1.99 



Asparagine nitrogen 



0.19 



0.99 



1.48 



i-33 



i-55 



113 



Nitrate nitrogen 



O 



0 



0 



0 



0 



0.21 



Here, a considerable increase of asparagine nitrogen in the 

 control case was observed. This increase may be chiefly due to 

 the transformation of other amido-compounds into asparagine, 

 as there was no nitrate stored up in the plants, and no de- 

 composition of proteids was observed. (I) 



Isolation of asparagine crystals from the plants treated with 

 ammonium chloride : — 10 grams of the finely powdered substance 

 were repeatedly extracted with warm water, and the extract, 

 after the addition of some tannin and basic lead acetate, was filter- 

 ed. To the clear filtrate was added an excess of mercuric nitrate 

 solution, whereby a white fiocculent precipitate was formed, 

 which, after washing, was decomposed with hydrogen sulphide ; 

 the filtrate from the mercuric sulphide was concentrated on the 

 water bath, the solution being kept always neutral by the addition 



(1) The hot aqueous extract of the wheat prepared with boiling water, gave with 

 phospho-tungstic acid a turbidity, and upon further addition of nitric acid, a fiocculent 

 precipitate probably due to peptone-like bodies was produced ; but when this extract was 

 first mixed with basic lead acetate until no more precipitate was obtained, the phospho- 

 tungstic acid produced in presence of considerable nitric acid, a smaller amount of 

 pulverulent precipitate, probably due to traces of a base like choline or betain. This 

 filtrate of the lead precipitate did not give any reaction whatever with caustic potash upon 

 the addition of a trace of copper sulphate (biuret reaction); therefore no peptone was 

 present. 



Neither ammonia nor urea was stored up as such in the treated plants. A finely 

 powdered dry sample was extracted with hot absolute alcohol, the alcohol was distilled 

 oft, and the residue after removal of impurities by basic lead acetate, was precipitated 

 with mercuric nitrate solution, the solution being kept almost neutral, the precipitate was 

 decomposed by hydrogen sulphide, the filtrate evaporated (keeping it always neutral by 

 the addition of baryta solution) and the evaporated residue again extracted with warm 

 absolute alcohol and evaporated again ; hereby no crystals of Urea, were observed nor 

 any crystallization upon the addition of nitric acid or oxalic acid. 



