88 FOREST PRODUCTS 



NiERENSTEiN, M. Chemic der GerbstofiEe. Stuttgart: F. Enke, 1910. 



Norton, T. H. Tanning Materials of Latin America. Bureau of Foreign and 

 Domestic Commerce, Washington. Special Agents Series, No. 165, 1918. 



Proceedings, American Leather Chemists' Association. 



Proceedings, Tanners' Council of the United States. New York. 



Procter, Henry Richardson. Leather Industries Laboratory Book of Ana- 

 lytical and Experimental Methods. Second Edition, Revised and Enlarged. 

 London: E. & F. N. Spon, Limited; New York: Spon & Chamberlain, 1908. 



Procter, Henry Richardson. The Principles of Leather Manufacture. Lon- 

 don: E. & F. N. Spon, Limited; New York: Spon & Chamberlain, 1903. 



Record, S. J. Our Present and Future Sources of Vegetable Tannins. Scientific 

 American. New York, 1916. Vol. 114, pp. 580-581. 



