186 Uuivf rsil !/ of Cal ijOniid V uhiic(iti(ni<; In l>i)tinni |\(>i,. 7 



Till' (liscovci'v of rubber in Chrt/sotlianDius, wliicli wms made about 



fifteen years ago, has been described by us in a icecnt [)ai)er-' as 



follows : 



Tlic I'lioii'c (if (']ir!i.s<>th(int)nis ;\Ui\ iclatcd "rcnora as tin- |il:ints fii-st to bf 

 iiivestiyati'il was tlio result of ;i proliniiiiary cxaniiiiatioii iii.nli' in IDOI. In 

 8i'i)t('iiib('r of tliat year tlie late Jmlgp A. V. Davidson, of I nilriMinliMicc, Inyo 

 County, California, sent some twijrs to tlic i)c|iaitincnt of Botany for idciitidcation. 

 with tlu' information that tho Indians jircpiircd from tlie ])lant a sort of ''t^um'' 

 Avhitdi they chewed. The plant was a sj)eeies of Clirysotlianiiius of the niavcolens 

 grouj). Further samples were submitted at our recpiest, and in Oetolx'r, 190-^, a 

 preliminary idiemi<-al examination of them was made by I'rofessor G. H. Colby, 

 of the California Kxjieriment (Station. This examination indicated the presence 

 of rubber, but not in sufficient amount to warrant further investijration. A report 

 to this effect was made public in the press and as a result some further examin- 

 ations were niaiie by at least one commercial rubber conii)any. The matter was 

 soon drojiped. however. It is probable that the plants used in tliis commercial 

 examination were of an entirely different s})ecies from those now bein<r examined. 



The examination of 1!)04 was followed with field work b,\- the senior 

 author in Inyo County in 1!)06, but no further ehenueal examinations 

 were made. Professor Marcus E. Jones informs us that steps were 

 taken about 1908 to erect a rubber-extraction plant at Salida, Colo- 

 rado, the intention being to use Rabbit-brush but the plan fell through. 

 He also tells us that as early as 1878 the Indians near St. George, 

 I^tah, taught some Mormon boys how to [)repare nd)ber by mastica- 

 tion of the inner bark of these plants. It is evident that the Indians 

 have long made use of the rubber as a chewing gum, but we have 

 been unable to learn of any scientific study of the plants as rubber 

 pi-odue( rs up to the time of our preliminary work in 1904. '■ 



II. ACKNOWLEDGMENTS 



Throughout the course of the investigation the autliois have had 

 the valual)le co-operation of a considerable nundx'i' of workers, some 

 of whom have given largely of theii- tinu' without reiiuinei-ation. In 

 the eai'ly stages of the work the chemical analyses were made by Pi"o- 

 fessor Paul L. Ilibbard. in the laboratory of the Division of Agricul- 

 tural ('JKiiiistiy of the California Exeriment Station and the staff of 

 that laboratoi'v, under the direction of Pi'ofessor .1. S. I'>urd, has given 



^Science, n.s., vol. 47, ji. 4.12 (May 10, 1918). 



^5 Since the above was written word has come to us that a factory w^as in ojut- 

 ation at Jluraiifjo, Colorado, as early as 190.') and that the company in charge of 

 it actually ]daced ujion the market i-ubber made from ' • h'abldt weed. ' ' How- 

 ever, the results of fiuther in<|uiiy indicat*' almost with ceitainty that the plant 

 used was not Chriisothanuiax, but the "Colorado Rubber IMant'' {II i/inrnojijs 

 floribiDula ^itilis). 



