(35) 
787. The same, No. 000. 
788. The same, No. oo. 
789. The same, No. o. 
790. The same, No. 20. 
791. Cork flour. This, like those which precede, is used in the making of linoleum. 
792. Bath matting. Matting used in bathrooms, made of a composition of ground 
cork. 
793. Linoleum.—An oilcloth substitute, composed chiefly of ground cork. Pre- 
sented by Arthur See, of Newark, New Jersey. 
794. Suberin——The substance lining the cells of cork tissue, which gives to the 
cork its peculiar useful properties. Suberin is chemically closely related 
to fat. 
795. The wood of the cork-wood tree or balsa-wood tree.—The wood of a species 
of Ochroma. Native of tropical America, where it is universally used in 
making rafts or balsas. In spite of its extreme lightness, about equaling 
that of cork, this wood is quite tough and strong. It is frequently used as 
a substitute for cork, for bottle stoppers. It is now being employed in the 
manufacture of airplanes. Presented by the American Wood Encysting 
Company, of New York City. 
796. Mexican wooden corks. Cactus corks.—Said to be made of the wood of a 
cactus, native of Mexico. Presented by H. H. Rusby in 1903. 
797. Native float for seines. Probably made of the wood of Annona palustris L. 
From Tortola, Virgin Islands. Presented by W. C. Fishlock, 1919. 
Paper Pulp 
Paper pulp is manufactured from various fibrous ma- 
terials, chiefly of vegetable origin. Formerly, it was made 
almost exclusively of cotton or linen rags and from straw, 
the object being to combine in an artificial texture plant- 
fibers consisting as nearly as possible of pure cellulose. 
In wood fiber these cellulose walls are largely overlaid with 
various plant substances which greatly interfere with the 
usefulness of the fiber in paper making. When processes 
were discovered for so treating the wood fiber as to remove 
these substances from the cellulose wall, the use of wood 
in paper making became established and is now the prin- 
cipal basis of its manufacture. 
798.15 A log of spruce wood.—From Picea mariana (Mill.) B.S.P. (Pinaceae— 
Pine Family). Native of northeastern North America. This is the form 
in which the wood is received at the paper-pulp mills of Caddyville, New 
York. 
15 The articles in this exhibit, unless otherwise specified, were presented by the 
International Paper Co., of New York City. 
