70 



THE INDIA RUBBER WORLD 



[November 1, 1911. 



the " rubber tree " that produced such a ripple of excitement. 

 It is botanically the Eucommia uhnoides. 



The specimens with which the Arnold Arboretum is experi- 

 menting were found at an altitude of about 3,500 feet on the 

 slopes of a mountain range near Yangtse-Kiang River, in 

 the neighborhood of Fang in the province of Hupeh. The lati- 

 tude of the region is about 32, the climate and topographical 

 conditions not unlike those of the mountainous districts of New 

 York and New England. 



Elsewhere in China the tree has long been cultivated, not for 

 the sake of extracting the rubber, but for the preparation of a 

 powder from the bark which is held to have medicinal virtues. 

 The leaves of the tree are smaller than those of the Ficus 

 elastica and are shaped more like those of the elm or beech, but 

 they have the peculiar gloss characteristic of trees and shrubs 

 which secrete caoutchouc. 



The existence of the Eucommia tilmoides was first brought to 

 the attention of European scientists about 1888 by Dr. A. Henry, 

 who sent to the Royal Botanical Gardens, Kew, some leaves, 

 flowers and seed pods which he had found under cultivation 

 in central China. 



The specimens were examined and described in the bulletin 

 issued from Kew by Dr. Francis W. Oliver, Quain professor of 

 botany in the University College, London, who gave the tree its 

 name. Further studies were made by Prof. F. E. Weiss, who 

 became interested in the discovery that was chronicled in the 

 "Transactions of the Linnaean Society" : 



"The threads of Eucommia consist of caoutchouc, for they are 

 insoluble in alcohol, acids and alkalis, though they become soft 

 when treated with ammonia. They dissolve in chloroform and 

 turpentine and swell up with ether. When heated they melt, 

 and they burn with the characteristic odor of burning rubber. 



"From the bark the rubber can very readily be extracted. If 

 the bark is broken in pieces and pounded in a mortar the mass 

 can be roughly separated into two parts, one consisting of the 

 tangled elastic threads with small bits of broken bark adhering 

 to them, the other chiefly of bits of bark containing no doubt 

 smaller pieces of the threads. From both parts chloroform will 

 dissolve out caoutchouc, a larger amount naturally from the por- 

 tion which consists chiefly of the threads." 



Prof. Weiss's quantitative examination showed that the bark 

 of the Eucommia contains about 3 per cent, by weight of caout- 

 chouc. "Whether the bark can be made use of commercially," he 

 concluded, "I must leave to those who are more experienced in 

 technical matters." 



After the first researches in England some further knowledge 

 of the newly discovered rubber tree was secured in France, where 

 it was successfully grown at the Jardin Colonial. In 1899 M. de 

 Vilmorin, writing in response to a question from Kew, told of the 

 hardiness of the importation : "Two plants of Eucommia ul- 

 moides remained uprooted against a wall in our Paris garden 

 during the two last winters and stood uninjured through as low 

 a temperature as 18 or 19 degrees Fahrenheit." 



On its native hillsides the tree grows to an average height of 

 about twenty-five feet. According to experience in China and at 

 the Jardin Colonial, Paris, it is propagated more readily from cut- 

 tings than from seeds. Dybowski and Fron, who have investi- 

 gated it at the French experiment station, reported : 



"It is not easy to get a quantity of seed and germination seems 

 to be slow and irregular. One sowing produced a single seedling 

 after the lapse of six weeks, a second after five months and others 

 later still. Fortunately cuttings seem to give better results. They 

 will strike root at any season and give vigorous plants." 

 The two investigators already mentioned say of the secretion : 

 "The product is of a dark brown color with metallic reflections 

 on the surface. Plunged into hot water it becomes soft again, 

 stretches out in flakes like goldbeater's skin, and under pressure 

 will take the impress of metal. In cooling it loses its suppleness 

 and becomes quite hard. 



"Wc have submitted the samples to ]\I. Leaute, an authority on 

 the subject, and he has been so kind as to authorize us to say that 

 he considers it gutta percha of good quality." 



Mr. Wilson, speaking of the tree, says : 



"One of the most striking discoveries of this trip was a new 

 kind of rubber tree which is hardy. We brought back a quantity 

 of the seed of this tree, and expect that it will grow in this cli- 

 mate. It is hardy, and on cutting away the bark one can see the 

 rubber lying in filaments between the fibers of the wood. The 

 rubber cannot be obtained as in the case of the caoutchouc tree, 

 by tapping the tree. It will not flow. The wood will have to be 

 macerated and the rubber extracted by some mechanical process. 

 Whether it will ever be commercially useful is impossible to say 

 now. The tree is allied to the magnolia." 



From all of the above it would seem that the tree produces, not 

 rubber, but a sort of gutta perclia. If the gum is high grade, and 

 if, as seems probable, it is adapted for cultivation on the hillsides 

 of New England and New York, it might well be even more valu- 

 able than if it did contain rubber. 



Speaking again of the milk weed, it is possible that the small 

 amount of rubber contained in it may some day be utilized. The 

 stalk certainly contains an excellent fiber, and of late it is com- 

 ing into favor as a food product cooked like asparagus. It has a 

 flavor most delicious, and seems to act like asparagus as a general 

 cleanser of the system. 



THE PROPAGATION OF GUAYULE. 



IN the opinion of Dr. Franes Ernest Lloyd, quoted in the Octo- 

 •^ ber issue of The India Rubber World, the ultimate and ade- 

 quate solution of the production of guayule shrub lies in the 

 direction of cultural rather than furestal operations. Illustrating 

 this assertion, the process of cultivation by seeds is described 

 in detail. 



The alternative system of propagation by planting has been 

 dealt with in an interesting statement by Professor Mario Cal- 

 vino, of the Central Agricultural Station, San Jacinto, Mexico. 



Seeing that the propagation of guayule {Parthenium argenta- 

 tum) by means of seeds, though apparently the most economical 

 system, had proved more or less unsatisfactory in practice, the 

 Central Agricultural Station of Mexico entrusted the study of 

 the question to the Division of Horticulture. That division made 

 use of a consignment of guayule seed, received from the Secre- 

 tary of Commerce, to study propagation in that form, with the 

 result that relatively few plants germinated. 



While Professor Calvino was making these experiments Seiior 

 Salvador Creci, the young agronomical chemist, announced that 

 he had some years ago succeeded in propagating guayule by means 

 of ligneous cuttings. This idea was approved by Professor Cal- 

 vino, and thereupon measures were taken to efifect the propaga- 

 tion of guayule on this principle, seeing that in this way are 

 propagated the Anthemis and the crysanthemum, which are of 

 the same family as the guayule shrub. 



The Central Agricultural Station obtained plants from Coa- 

 huila, from which ligneous, seed-bearing and herbaceous cuttings 

 were taken, for planting in boxes in the open air and also in 

 frames beneath glass. The herbaceous and seed-bearing cut- 

 tings germinated in ten days, and the ligneous ones within IS 

 days in the frame and 20 days in the open air. 



The cuttings thus matured were afterwards planted in nur- 

 series, being placed 2 inches from each other in rows of 2^4 

 inches apart. They descended from 5 to 8 inches into the soil 

 of the nursery, which was well sifted beforehand and mixed 

 with sand. It is considered desirable to add calcareous earth. 



Upon the cuttings being planted, the nurseries should be pro- 

 tected with mats or blankets to prevent the sun from drying or 

 injuring the plants. This protection likewise serves to neutralize 



