i65 



The distillations, in both cases, were continued for six hours. Although over 

 three years had elapsed between the two periods, yet, the oils were found to be 

 practically identical, consisting very largely of dextro-rotatory limonene and 

 dipentene. In the leaf oil of this species of Callitris, the limonenes appear to have 

 reached their maximum, largely to the exclusion of the pinene. From the results, 

 certainly not less than 85 per cent, of the oil from this species belonged to the 

 limonenes, mostly as dipentene. The predominant limonene was the dextro- 

 rotatory form, and in the oil of the January sample had the rotation a little less 

 to the right than had the other. This result indicated that at a certain time of 

 the year (midsummer) the larger amount of the laevo-rotatory form is present, 

 and, consequently, the oil has a less rotation to the right at this time than at 

 other periods of the year. This peculiarity has been noticed with the oils of other 

 species of Callitris. The chemical characters peculiar to the oil of this species, show 

 it to be distinct from that of any other Callitris. The one nearest to it is C. intra- 

 tropica, but in the oil of that species the predominant limonene was found to be laevo- 

 rotatory, and is the species in which the laevo-rotatory form appears to reach a 

 maximum. The limonenes were so pronounced in the oil of C. arenosa, that the 

 tetrabromide could be formed in abundance from the crude oil alone, without 

 the oil undergoing any preparation whatever. The physical results also indicated 

 that limonene was mostly present in the oil. The tetrabromide was fractionally 

 crystallised from acetic ether, with the result that the fractions melted at 

 different temperatures, and that the one which separated first had the highest 

 melting point. When dissolved in cold acetic ether, the tetrabromide was found 

 to be dextro-rotatory. It is thus evident that both dextro-rotatory limonene and 

 dipentene, or in other words, both forms of limonene, occur in the oil of this species^ 

 as with those of the Callitris generally, and that the dextro-rotatory form here 

 predominates. The amount of ester was small, but it appeared to consist of 

 the acetates of both borneol and geraniol, thus resembling the esters from most 

 species of Callitris. 



No. 1. — This material was collected at Ballina. It consisted of tne extreme 

 terminal branchlets with very few fruits. 592 lb. gave 38-1 oz. of oil, equal to 

 0-402 per cent. The crude oil was light lemon-coloured, and had an odour slightly 

 resambhng the ordinary " Pine-needle oils," but with a marked lemon-hke odour. 

 It was insoluble in ten volumes of 90 per cent, alcohol. The specific gravity of 

 the crude oil at f |° C. = 0-8491 ; rotation a^= + 35'8°; refractive index at 23° C. 

 == 1-4760. The saponification number was 14-77, equal to 5-17 per cent, ester. 

 On redistilhng, only i per cent, came over below 167° C. Between 167° and 172°, 

 36 per cent, distilled; between 172° and 177°, 44 per cent.; between 177° and 

 180°, 10 per cent. As this represents 91 per cent, of the total oil, and as 5 per 

 cent, of the esters were present, it is evident that the high boiling constituents, 

 as the sesquiterpenes, &c., could only be present in a very small amount. 



