226 I' iih'i rsihj of ('(illfoni id I'lihl ic<it itnis^ in /ioftnii/ [\<)i.. * 



IX. HEsn/rs OF THE CHHMICAL analyses and MK'RO- 



SCOrU'AL EXAMINATIONS; TAP.FLATION OK PER- 



CENTACJE OF Hl'RRER IN EACH VARIETY 



The methods eiui)h)y('(l in inakiii<i- Ihe chcniical analyses and 

 inieroseoi)ieaI exaininations iiave Ix'cn detailed elsewhere (cf. p. 1210). 

 The following tables give the residts of sueh analyses and examina- 

 tions as wei'i' made on individnal plants of a nnndici" of varieties of 

 C. nauscusus. As in pfcvions tables the eollectioji number is iiiehuled 

 for the sake of eompleteiiess and foi" future referenee. Tlic date of 

 analysis is not given because of eonsiderations uicntioiicd al)ov('. The 

 "X" following certain of the jiercentages indicates tliat tiiey ai'e not 

 based upon dry weight. In all other eases moisture determinations 

 were made, and the figures are based upon dry weight. 



The terms used in describing the amount of rubber determined by 

 microscopical examination are only relative and are derived from a 

 more elaborate classification used during tlie course of the investi- 

 gations. 



In the reports on the chemical analyses, the first column, or 

 "acetone extract" is taken to represent the percentage of resins, fats, 

 waxes, etc., in the sample while the second column indicates the per 

 centage of pure rubber, or C-hrysil. As indicated on page 223, the 

 figures in this second column are probably too low by a fraction of 

 1 per cent in each case owing to the difficulty of obtaining the proper 

 degree of fineness in grinding the samples. 



A summary of these tables is given on page 244. 



We are under great obligation to Miss Mildred Crane who under- 

 took the carrying through of the majority of the chemical anah'ses 

 and assisted during the entire investigation in a variety of ways. 



Table (i. — Resi'lts of Chemical Analyses and Microscopical Kxamixations 

 OK Jndiviihai- Plants of Twelve Varieties of Clirysofltomnu.'i lunisrosu.s 



Chrysothamnus nauseosus (schku sfrictu) 



Microscopical Examinations 



Place of Collection 



251 Xeai' Harney, Ore. 

 46.3 Mono Lake, Calif. 



