111. 



THE INDIA RUBBER WORLD 



[January i, igio. 



Guayule Factory of the Texas Rubber Co. 

 [At Marathon, Texas, First in the United States.] 



Loaded Wagons Arriving at Factory. 



[The Texas Rubber Co., at Marathon.] 



field. The more important known facts it will be worth while 

 to indicate. 



Natural reproduction in the field takes place in two ways, 

 by seed and by means of shoots (rcloiios) which start up from 

 the shallow lying roots. Space does not permit me here to 

 compare the efficacy of these two methods, but it will suffice 

 to indicate that they are, in effect, complementary. Retoiios are 

 relatively few in numbers, but their initial growth is rapid and 

 they quickly produce flowers. Further, their numbers are in- 

 creased by injury to the top of the plant. The more of the 

 upper part of the plant is removed, the more likely the roots 

 are to produce retonos. Even portions of roots alone fre- 

 quently do so. and this after dying back quite a distance. The 

 phenomenon is well known, and this it is which has led to the 

 extravagant notion referred to in the preceding paragraph. 

 Nevertheless, it is true, broadly speaking, that on account of 

 the readiness with which retonos are formed, it will be diffi- 

 cult to completely eradicate the guayule, which is different from 

 saying that, in five years, "ya esid otra ves." 



How tiii Rubber is Contained. 



The internal structure of the plant is of more than academic 

 interest, for the peculiar occurrence of the rubber furnishes 

 the rationale of the success of the mechanical method of 

 extraction. The more obvious details have been known 

 since 1901. when Fron and Francois, French botanists, 

 published a brief account of them. Later Ross (1908), 

 and Lloyd (1908), extended this knowledge. Of interest here is 

 the fact that the rubber, in sharp contrast to the condition found 

 in latex plants, occurs in small, indeed microscopic particles 

 within the cells of the pith, medullary rays and cortex (bark, 

 so-called). Practically, then, each particular particle is com- 

 pletely surr mnded by a membrane of cellulose. Obviously, the 

 task of the extractor is to set free the minute masses of rubber 

 and 1 thi same time to bring them into close contact so that 

 larger masses will result, and to completely separate the cellu- 

 lose (together with wood and cork) from the rubber. Because 

 of the circumstance that the rubber bearing tissues are pene- 

 trated longitudinally, from the top of the plant tc the bottom 

 by canals which are filled with resin,* this becomes mixed with 

 the rubber during extraction to the extent of 25 per cent., which 

 amount may be lowered by suitable processes. 



The general occurrence of rubbers and resins in various plants, 

 particularly in the guayule, has led to the notion that these sub- 

 stances stand in physiological relation to each other, and that 

 as the season advances the resin becomes changed into rubber. 

 I have at hand abundant evidence, however, that this cannot 

 be the case, and contrariwise, that the process of rubber secre- 



*The value of this resin, as at present understood, is discussed by H. O. 

 Chute. The India Rubber World, July 1. 1909 — page 351. — f. e. l. 



tion is quite independent of that of resin. This is shown par- 

 ticularly by plants under irrigation, in which the formation 

 of rubber is delayed, but that of resin not. 



The effects of irrigation upon the guayule beyond that just 

 mentioned are very marked. These have been studied ex- 

 haustively, but here may be mentioned briefly only that the 

 ratio of rubber producing tissue to the remaining, non-producing 

 tissue is lowered in two ways, namely, by the relatively greater 

 development of the wood cylinder and by the reduction of the 

 thickness of the medullary rays. In addition to this, there is to 

 be noted an increased hardness of the wood in which mechan- 

 ical elements preponderate. The stems of irrigated plants show 

 furthermore a strong tendency to run out into flowering shoots 

 which die back. All this is compensated for, however, by the 

 much more rapid rate of growth which, in irrigated plants 

 averages five to eight times that of field plants. This, in the 

 light of the fact that the deposition of rubber in the tissues of 

 plants grown with extreme rapidity under irrigation, though 

 at first relatively very slow, goes on steadily to a maximum which 

 may be compared favorably with the maximum in field plants, 

 is distinctly encouraging to those who hope to compass the 

 successful cultivation of the plant. I do not ignore certain 

 secondary practical difficulties, such as questions of cost, which 

 constitute the business problem, but the one time greatest doubt 

 as to the responses in the regard of rubber secretion may be 

 retired. The evidence is to appear later, in extenso. 



Guayule Factory Processes. 



We may now glance at the process of manufacture of the 

 crude material from the shrub. Public attention was drawn to 

 guayule rubber for the first time by a small exhibit made at the 

 Centennial Exhibition at Philadelphia in 1S76, sent from Du- 

 rango.t It was not until r888, however, that foreign attention 

 was definitely drawn to the product, at first, it seems, in Eng- 

 land, and very shortly after in Germany. In 1900 crude shrub 

 was shipped to Hamburg, and from this small amounts of rub- 

 ber were recovered and placed on the market. In the following 

 year a laboratory was established by some interested Germans 

 at San Luis Potosi, and the measure of success here had led up 

 to the establishment, in 1902, of a factory at Timulco. At this 

 time also interested Americans began to conduct experiments 

 at Torrcon. The Jimulco factory placed rubber on the market 

 for the first time in 1905, while the efforts of the Americans 

 culminated in the shipment of crude rubber into the United 

 States in 1904, though in small amounts. For a period between 

 the days when guayule shrub was bought for fuel to be used 

 in smelters at the rate of 8 pounds for one cent gold till 1904 



tFollowing this display a leading rubber manufacturer imported to New 

 York a steamer load of the shrub, with results stated in The India Rubber 

 World, April 10, 1909 — page 199. — The Editor. 



