45 



a small quantity of colorless, strongly alkaline liquid, sparingly 

 soluble in water, but readily soluble in alcohol and ether. The 

 solution was tested with the following results: 



On warming with hydrochloric acid and allowing to stand 

 a short time a fine red precipitate separated. With sulphuric 

 acid and quinone a green precipitate formed ; with phosphomo- 

 lydic acid, first a yellow, then a blue precipitate ; with potassium 

 ferrocyanide, dark green ; with quinone alone, violet red. The 

 contents of the second flask was also alkaline. The distillate 

 was also tested by the Lassaigne test, but no Prussian blue ob- 

 tained. As pyrrol gives the Lassaigne test it must be that the 

 distillate did not consist of pyrrol, but was a pyrrol derivative. 



Another evidence of the presence of nitrogen was obtained 

 as follows : An ordinary open combustion tube was filled with 

 copper oxide and ignited in a current of oxygen. After partially 

 cooling, a platinum boat containing the gum was introduced 

 and the gum burned in a current of oxygen. The products 

 of combustion were conducted through potash bulbs containing 

 a solution of potassium hydroxide, prepared from metallic po- 

 tassium, and water distilled with potassium permanganate. Just 

 before the combustion the solution was tested and found to be 

 free from nitrogen compounds. After the combustion the solu- 

 tion was tested with diphenylamine when it gave the blue color 

 characteristic of nitrates. With brucine and sulphuric acid a red 

 color and with sulphuric acid and sulphate of iron the brown ring 

 appeared. 



This proves conclusively that the gum contained nitrogen in 

 some form, which is converted into pyrrol, or a pyrrol derivative, 

 by heating with potassium hydroxide. 



ATTEMPTS TO SEPARATE THE GUM FROM THE ENZYME. 



Hikorokuro Yoshida states that by removing his so-called 

 urushic acid with alcohol and extracting the residue with cold 

 water, and then boiling the solution, a white precipitate is formed. 

 He assumes that it is the enzyme, but does not prove it, except 

 that the solution was active before boiling and inactive after- 

 wards, and that the precipitate contained nitrogen. It may have 

 been an inactive vegetable albumen, although he states that it 

 contained less nitrogen than these bodies usually contain. I have 

 found, however, that a solution of the purified gum obtained by 



