Gums, Resins, 



486 



[December, 1909. 



taken weigh dry from 1 to 4 pounds. 

 Thus on an acre we should find from 

 1,000 to 8,000 pounds of the shurb. If 

 we call the average yield two tons per 

 acre, we may estimate the area harvest- 

 ed at fifty acres for one day's consump- 

 tion at a large factory. 



While the fact is patent that the sup- 

 ply of guayule is decreasing and must 

 ultimately be exhausted, the opinions of 

 experts place the date, some at ten, some 

 at twenty years hence. Large factories 

 running steadily at Parras, Torreon, 

 Saltillo, and elsewhere, using the pro- 

 duct of no less than 100 acres every 

 day, the activities of the camps which 

 the traveller may see in dozen places in 

 a day's journey ; the bales of the shrub 

 piled high by the siding awaiting ship- 

 ment, all point to the speedily approach- 

 ing day when the factories must shut 

 down for want of material. 



This menace to the business interests 

 involved has not been overlooked cr 

 ignored. To provide a continuous crop 

 upon which the business could depend 

 is an idea that has appealed, not only 

 to the members of interested corpor 

 ations, but also to private land-holders, 

 who appreciated the income prospective 

 from such an enterprise. Experiments 

 here and there have been tried, and 

 various opinions have taken form as 

 to the prospect. The most notable of 

 these experiments was that conducted 

 at the instance of the Continental- 

 Mexican Rubber Company, who recently 

 established an elaborate department of 

 investigation at Cedros, Mexico, and 

 spent much money in foi warding the 

 work. Although less than a year was 

 allowed for this large task, the time 

 sufficed to show some insuperable 

 obstacles to the cultivation of the plant 

 on any thing like an economic scale. 



In the first place, the slow production 

 of seeds, and the care required in their 

 planting, and the rearing of young 

 plants, make the procedure unprofitable 

 from an economic stand point. With a 

 possible germination rate of 10 per cent, 

 of the seed sown, the failure through 

 one cause or another of the young seed- 

 lings to pass the initial stages of develop- 

 ment, the ranks of the young plants 

 again depleted by pest or parasite, the 

 loss by accidents or in process of trans- 

 planting, and a few subsequent vicissi- 

 tudes both possible and probable, make 

 it doubtful whether one can count on as 

 much as 1 per cent, of the seed sown to 

 mature plants, even under the most 

 favourable conditions. Cuttings mostly 

 fail to grow except from portions of the 

 roots, or stems having part of the root 

 system in connection with them, and 



only under certain conditions of irri- 

 gation ; even then, as in the case of 

 seedlings the cost of the operation 

 exceeds its value. Irrigation is quite 

 essential to the starting either of seeds 

 or cuttings, and in the subsequent 

 growth the rapidity of development 

 depends upon the quantity of water 

 supplied. 



But the rapidity of development is in 

 inverse ratio to the formation of rubber 

 in the tissues. Plants grown under irri- 

 gation grow rapidly, and attain in four 

 years a weight of six pounds or more, 

 but the rubber content in such plants 

 is practically nil, while in native desert- 

 grown plants it is about 10 per cent, of 

 the dry weight. If, however, water is 

 withheld, as under desert conditions, 

 the plants grow very slowly, and it is 

 doubtful whether a crop could be 

 matured much under twenty years. Of 

 course, rubber is present in desert- 

 grown plants at an age much less than 

 this, but it is a question at what age 

 plants may be most profitably taken, 

 though certainly not less than ten years. 



Reforestation by natural processes 

 must be very slow, and as in the case of 

 the lumber forests of the North, the 

 second growth is never equal to the 

 first. A guayule seed in the desert has 

 about one chance in the thousand of 

 coming up, and thereafter danger from 

 drought, disease, and accident make its 

 hold upon life exceedingly uncertain. 

 The only hope of prolonging the business 

 seems to be in so harvesting the plants 

 that the roots are left in the ground ; 

 from these new shoots will arise, and in 

 a few years possibly yield another crop 

 worth the taking, How loug this 

 process can be kept up profitably is at 

 present unknown. However, the 

 guayule rubber industry seems destined 

 to have its day and pass out. 



The above statements are issued only 

 after much observation and experiment, 

 the details of which are soon to be 

 published in a book under the joint 

 authorship of the investigators. 



RUBBER PRICE CONDITIONS, 



(Prom the India Rubber World, Vol. 

 L„ No. 2, May, 1909.) 

 The topic of the utmost interest in the 

 india-rubber industry to-day, and that 

 which is most considered, is the present 

 and prospective price of crude rubber. 

 Whether the manufacturer be located 

 at Maiden, Manchester, Mannheim, 

 Melbourne, Menin, Milan, Mjondalen, 

 Montargis, Montreal, or Moscow, the 

 question is ever present, as one which 



