Extraction of Rosin-free Wood with Alkali 



To study the behaviour of the humus, pine 

 shavings were first extracted with ether and then 

 heated with dilute solutions of caustic soda. The 

 alkali extracts were clear, and brown or cherry red 

 in color. 



Addition of excess caustic soda caused no precipi- 

 tation of the organic bodies. The same was true 

 of treatment with sodium chloride. Barium chlo- 

 ride gave a fine, brown precipitate of the barium 

 salts of the humic acids, leaving a pale orange- 

 colored supernatant liquor. Titration with mineral 

 acids gave no precipitate up to the sodium bi- 

 carbonate stage (phenolphthalein end-point). On 

 fully acidifying, there resulted almost complete 

 precipitation of the humus, due to the breaking up 

 of the sodium salts. The humus was brown, granu- 

 lar and easily washed by water. Only a trace 

 proved soluble in ether, but the mass became some- 

 what gelatinous. After acidifying a portion of the 

 alkali extract to the sodium bicarbonate stage, 

 CO 2 was passed through the solution. A large 

 proportion of the humus was precipitated, (see 

 Rinman, U. S. Patents 1,005,882, 1,017,320 and 

 1,045,889, and J. Soc. Chem. Ind., 31, p. 183). 



Extraction of Resinous Wood with Alkali 



The behaviour of the resinous wood with alkalis 

 is modified by the presence of rosin and turpentine. 

 Dilute caustic soda and sodium carbonate showed 

 little action on resinous shavings or chips in the 

 cold. Shavings were readily extracted, however, 

 by heating at 70-100C. Chips were much more 

 resistant, although the small chips were thoroughly 

 extracted on boiling with dilute caustic soda for 

 1^-2 hours, accompanied by evolution of turpen- 

 tine. 



The brown extracts consisted mainly of sodium 

 resinate and the sodium salts of humic acids. Ad- 

 dition of excess caustic soda in the cold caused 

 precipitation of most of the rosin soap, which car- 

 ried down some of the humus mechanically. So- 

 dium chloride gave the same general action. Bar- 

 ium chloride gave a precipitate of the barium salts 

 of both the rosin and humic acids. As in the case 



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