I 20 



colour in consequence. This was particularly the case with the oil of E. tittered, 

 and ii was found that if care were not taken in the rectification, copper could be 

 detected in the distillate. When iron alone was present in the oil this did not 

 occur, so that eventually copper fittings were in most cases discarded. 



As an illustration of the amount of copper likely to occur in oils of this 

 class, if copper fittings are used, the following is given : — When crude Eucalyptus 

 oils are rectified by direct distillation, a portion of the water absorbed in the oil 

 comes over in the first distillate, and this contains practically the whole of the 

 free volatile acid occurring in the oil. Our thanks are due to the Australian 

 Eucalyptus Oil Company for supplying us with about two litres of this water, 

 which they had collected when rectifying the crude oil of Eucalyptus ciuerea. 

 This water was strongly acid, and of a bright green colour, due to the presence 

 of the copper in solution. The water had also a strong odour of the volatile 

 aldehydes. It was made alkaline by the addition of sodium hydrate, the 

 precipitated copper filtered off. and the precipitate dried and ignited. The copper 

 was then dissolved out, and finally precipitated as metal on a platinum dish. 

 The amount of metallic copper thus obtained from 2 litres of water was 0-8772 

 gram., equal to 0-0438 per cent. It must be remembered, too, that this result 

 only represented that portion of the copper which came over on redistillation. 



The amount of free acetic acid in the water was determined bv titrating 

 10 grams, with semi-normal soda. The amount of NaOH used was 0-140 grams., 

 equal to 2-1 per cent, acetic acid. (See also the article on "The Free Volatile 

 Acid of Eucalyptus Oils.") 



61. Eucalyptus dealbata. 



(A. Cunn., Schau. in Walp. Rep., ii, 924.) 

 Cabbage, White Gum, or Mountain Gum. 



Systematic. — A fair-sized tree, from 60 to 80 feet high, with a smooth 

 bark, which is occasionally rough at the base. Abnormal leaves lanceolate, 

 acuminate, or shortly so, 4 to 6 inches long, and under 2 inches broad, pale 

 bluish ; intramarginal vein well removed from the edge, especially in the 

 short broader leaves. Normal leaves lanceolate, generally under 6 inches long, 

 not shining ; venation well marked, lateral veins oblique, spreading, intra- 

 marginal vein removed from the edge. Peduncles axillary, short, 4 lines long, 

 with four to six flowers in the umbel. Calyx conical, about 2 lines long ; 

 pedicel short or long, occasionally angular; operculum conical, obtuse, equal 

 to or longer than the calyx. 



Fruit. Hemispherical; rim flat, or slightly con- 

 vex; valves acuminate, exserted. often 

 resembling those of E. oleosa, F.v.M. ; 2 

 lines long and z\ lines in diameter. 



The fruits arc constant in shape, not unlike ti/o^t of 

 E. resinifera with thetruncate rim, but somwehat smaller- 



Habitat. — Condobolin to Manildra, Cowra, Grenfell, Tenter- 

 field, Murrumbo, Rylstone, New South Wales; 

 Victoria: ( lueensland. 



