September 1, 1914.J 



THE INDIA RUBBER WORLD 



645 



Growing Rubber in Ohio. 



OHIO has had such overwhelming success in the produc- 

 tion of rubber goods, why should it not also succeed 

 in the production of crude rubber? 



Mr. Charles P. Fox, a well-known rubber chemist of that 

 state, is authority for the statement that Ohio can and does 

 produce crude rubber in two different varieties of plants, but 

 unfortunately the percentage of rubber in these Ohio botanical 

 rubber plants is so small as compared w'ith the percentage of 

 profit in the Ohio rubber plants of brick and mortar that there 

 is not likely to l)e any immediate rush into the occupation of 

 producing crude rubber in that state. 



Mr. Fox read two interesting papers at the last two annual 

 meetings of the Ohio Academy of Science. Both of these — the 

 first paper entitled "Ohio Grown Rubber" and the second entitled 

 "Another Ohio Grown Rubber" — were iirintcd in the "Ohio 

 Naturalist." 



While not encouraging from the standpoint of the investor, 

 these papers are distinctly interesting from the standpoint ot 

 rubber botany. We produce them below : 



Ohio Grown Rubber. 

 Product of Common Milki^'ecd (.-Isclcpias Syriaca). A 

 common plant belonging to the Asclcl'iadcac; found abundantly 



Pl.\xt .\t Left, Milkweeu (Asclcpias Syriaca). Which Grows 



Adund.\ntlv Everywhere in the United St.\tes. Plant 



AT Right, Milkweed (.Uclcfias Coniutii). Best E.x- 



AMPLE OF A Native Rubber Producing Plant in 



the North Temperate Zone. 



throughout the United States ; classed as a weed, convicted as a 

 bee-killer, advocated as a rubber producer. Too well known to 

 need description. 



Latex. ^lilk-like, thin ; acid or neutral reaction ; charac- 

 teristic odor of milkweed ; does not coagulate on standing in a 

 closed vessel; imperfectly coagulated by acids; thickened or par- 

 tially coagulated by ammonia ; coagulated by heat ; coagulated by 

 alcohol. 



Coagulated Latcv. The coagulum is plastic and can be 



molded into cakes resembling some of the cheaper grades of 

 rubber. The whey contains mineral matter and sugar. 



Caoutchouc. Obtained from the coagulum. Is flabby; lacks 

 strength and firmness ; is high in gravity. Responds to the sul- 

 phur chloride and bromide tests. Yield of rubber, on basis of 

 latex, is 2 to 3 per cent. 



Resin. White, tasteless, odorless. Gives "asclepione," de- 

 scribed by Watts as radiating crystals insoluble in water and 

 alcohol, and is not attacked by dilute caustic. 



This plant has been suggested as a source of crude rubber. 

 The project has engaged the serious attention of several parties 

 during the past twenty years. A careful study of the question, 

 covering a period of twelve years, indicates that while rubber is 

 a product of the plant, the amount is so small, its quality is so 

 inferior and its cost of production is so high, that a profitable 

 industry is out of the question. 



Another Ohio Grown Rubber. 



Of the inany kinds of crude rubber, the botanical family, 

 Apocynaccae, produces its share of good grades. Mangabeira 

 (genus Hancornia in Brazil), Benguela root rubber {Landolphia) 

 and Funlumia, both .-Xfricans, are notable examples. 



The Apocynaccae are trees, shrubs and herbs, with a milky 

 acrid juice, numbering some 1,000 species, grouped into 130 

 genera, inhabiting sub-tropical areas. This family of plants pro- 

 duces a varied line of economic products, such as edible fruits, 

 dyes, drugs, fibres, ornamental plants and caoutchouc. The 

 Madagascar Ordeal Plant, whose seed contains the most powerful 

 poison known, and Eden's Forbidden Fruit, register here. 



Several members of the type genus Apocynuin, of this family, 

 are common to the United States, the so-called Indian Hemp, 

 ^■\pocynum cannabium and A. androsaemifotinin. During the 

 summer of 1911 I examined the latex of the latter species for 

 quantity and quality of its rubber. The results of this investiga- 

 tion show that the latex of this plant gives a small quantity of 

 good grade rubber. 



The late.x is white, viscous, neutral or sliglitly acid, and has the 

 strong acrid odor peculiar to this plant. The late.x reacts with 

 the usual coagulating reagents, in the following manner: 



.Vcids do not coagiilate ; latex becomes thin. 



.\lkalies do not coagulate; restore the viscosity; change the 

 color from white to brownish yellow. 



Boiling coagulates slightly and slowly. 



.Vcetone in proportion of one-tenth volume coagulates imme- 

 diately and completely ; liquid is colored chocolate red. 



Formaldehyde coagulates readily, but is much slower than 

 acetone. 



Phenol coagulates the latex, but gives a soft product. 



Salt solution coagulates slowly, giving a finely divided pre- 

 cipitate, hard to coalesce. Boiling the saline solution gives a soft 

 product ; not successful. Of the above methods, the use of 

 acetone or alcohol, and formaline, are the only ones recom- 

 mended. Of these two, acetone is preferred. 



The latex of Apocynum differs from that of Asclcpias in that 

 It coagulates spontaneously, even if it is kept in closed containers. 

 The spontaneously coagulated latex gives : 



Liquid portion 67.58 per cent. 



Cheese (wet) 32.43 per cent. 



The li<iuid is white, sUghtly acid and acrid in odor. This liquid 

 failed to coagulate after addition of more acid. Slight excess of 

 alkali increased its viscosity, changed its color from white to 

 brownish yellow, but did not coagulate or precipitate it. Boiling 

 had no effect. Excess of acetone gave a finely divided precipitate, 

 the particles of which were not cohesive. Evaporation of the 

 mixture, after washing with water and treatment with boiling 



