AND THEIR ESSENTIAL OILS. 173 



the want of eucalyptol, show the oil to be distinct from 

 that of E . fastigata. (See " Research on the Eucalypts," 

 p. 146, for (lata concerning the oil of that species.) The 

 saponification number of the Victorian oil was 12'4. The 

 comparatively small yield of oil from the leaves and 

 branchlets of K . it (pidns renders this species of little value 

 as an oil-producing tree, and quite a number of Eucalypts 

 are now known which yield phellandrene oils in much 

 greater abundance. 



EUCALYPTUS RISDONI, Hook. f. 

 C' Blue Feppermiiit." ) 

 Botany. 



IJisforical. — This species was described by J. D. Hooker 

 in his '' London Journal of Botany," published in 1847, 

 but was synonymised by Mueller under E . amygdalina in 

 his " Eucalyptographia " (Dec. V.). 



Remarks. — ^Those given in our work on the '' Eucalypts 

 and their Essential Oils " (p. 208) apply equally well 

 to-day. 



They read as follows : — " The life history (if one may use 

 the expression in this connection) of this Eucalyptus is 

 identical with that of the mainland species E. dives, 

 Schau., in that it flowers and fruits when quite a small 

 shrub, and when all its leaves are in the opposite, sessile, 

 cordate form. Singularly enough, both Hook. f. and 

 Schauer founded their species on the shrubby form only, 

 and in the case of ?J . dives it was not, till shown by this 

 research that the mature trees became identified, whilst 

 Hook. f. figures and describes {loc. r/'f.) what has since 

 been shown to be the primary stage of growth of his 

 species, the mature trees of which are recorded by Ben- 

 tham in his ' Flora Australiensis ' (HI-, 203) as var. elata 

 on material collected by Gunn. The dried material 

 of the early and mature forms of this tree, when compared, 

 would easily mislead one not acquainted with the trees in , 

 the field. Mueller unites E. Risdoiii altogether with 

 E. amj/cjdcdina, but our results agree with those of J. D. 

 Hooker and Oldfield, and in no way do we see so close an 

 affinity between these two trees." 



Rodway, in his " Flora of Tasmania," follows Ben- 

 tham, and records a variety elata. Our investigations, 

 however, show that the trees growing at the foot of Mt. 

 Wellington, and regarded by Rodway as var. elata, are 

 merely taller trees of the species, and differ in minor 

 respects only, botanically or chemically, from the smaller 

 trees or shrubs. 



