274 



149. Eucalyptus piperita. 



(Smith, in Trans. Linn. Soc., iii, 286 partly.) 

 The Sydney Peppermint. 



Systematic. A tall tree, bark fibrous, but not so furrowed as in the 

 " Stringy barks," hoary on the outer surface. Abnormal leaves ovate, ovate- 

 acuminate, lanceolate, almost membraneous, pale-coloured underneath, 2 to 

 6 inches long; venation faintly marked, lateral veins oblique, spreading, intra- 

 marginal vein slightly removed from the edge. Normal leaves lanceolate, not 

 large, rarely exceed 6 inches, oblique, not coriaceous, very acuminate, not 

 shining ; venation not prominent, lateral veins distinct, oblique, spreading, petiole 

 slender. Flowers in axillary peduncles or panicles, or clustered at the base of 

 the branchlets. Buds about 6 lines long. Calyx tube small, a little over i line in 

 diameter, hemispherical, or slightly tapering into a pedicel a few lines long ; oper- 

 culum conical, acute. 







Fruit. Dimorphous, pilular, shortly pedicellate, 

 sometimes contracted below the rim, when 

 it becomes quite urn-shaped ; rim thin ; 

 valves not exserted ; about 3 lines in dia- 

 meter. 



The fruits cannot well be confounded with any other. 



Habitat. Sydney, Coast District, and Tableland, New South 

 Wales; Victoria; Queensland. 



REMARKS. In this research particular interest pertains to this species, as it was from trees of the " Sydney 

 Peppermint," growing where Sydney now stands, that the first Eucalyptus oil was obtained. It was distilled by 

 Dr. White, Surgeon to the First Fleet, in 1788. 



ESSENTIAL OIL. Leaves and terminal branchlets for distillation were 

 obtained from Gosford, N.S.W., in April, 1897. The yield of oil was 0-8 per 

 cent. The oil was light-coloured, and had a distinct peppermint odour due to 

 the ketone piperitone. Phellandrene was present in some quantity, as was to 

 be expected from the characteristic venation of the mature lanceolate leaves; 

 pinene was also found in small quantity. Cineol occurs to the extent of about 

 20 per cent, in the crude oil. Crystallised eudesmol was found, and it was in 

 this oil that we discovered that constituent. The higher-boiling portion .consisted 

 largely of the sesquiterpene. 



The crude oil had specific gravity at 15 C. = O-QIII ; rotation a D -- 2-7; 

 refractive index at 20 = 1-4781, and was soluble in i volume 80 per cent, alcohol. 

 The saponification number for the esters and free acid was u-o. 



On rectification, i per cent, distilled below 170 C. (corr.). Between 

 170-183, 77 per cent, distilled ; between 183-198, 9 per cent, came over ; the 

 temperature then rose rapidly to 266. Between 266-272, 8 per cent, distilled. 

 The third fraction consisted largely of eudesmol. 



