78 



PROCEEDINGS OF SECTION B. 



also is large, so that one cannot see why this tree should not by 

 systematic cultivation be made the means of supplying the world 

 with this useful product, and could probably be made to largely 

 take the place of Lemon-grass oils. There is no reason to suppose 

 that the oil from the young plants of this species would differ, either 

 in composition or yield, from that obtained from older trees, and 

 in this respect it should follow the general rule with Myrtaceous 

 plants, so that a suppty of oil might be assured at a very early stage 

 in the life of the tree. Citral is the aldehyde of the alcohol geraniol. 

 It was first isolated from the oil of Backhoiisia citriodora, and was 

 named citral because the constituent of lemon oil, to which the 

 odour is due, was found to be identical with it.^ Besides its other 

 uses, citral is the principal constituent in the manufacture of 

 lonone, the artificial violet perfume. 



As there was some uncertainty as to the exact amount of oil 

 yielded by the leaves of this tree, material was obtained from 

 Eumundi, Queensland, and forwarded in the month of May. The 

 branchlets were collected exactly as would be done commercially, 

 for oil distillation. The material was sent by sea, but it had only 

 partly dried by the time it reached the Museum, as it had been 

 packed in bags. The amount of oil obtained was equal to 1-415 

 percent. Schimmel & Co.- give the yield as 4 per cent., but this 

 result was probably not founded on the distillation of term-inal 

 branchlets. 



The first investigation into the composition of the oil of this 

 tree is recorded in Schimmel's Berichte (loc. cit.), and it is there 

 shown to consist almost entirely of citral, and to have a specific 

 gravity 0'9. An analysis of a sample of the oil was carried out by 

 the chemists of the Imperial Institute, London.^ Another analysis 

 later still was undertaken in London by J. C. Umney and C. F. 

 Bennett.* To these may now be added the results of my own 

 investigation. These results show that constancy of results 

 is to be expected with the products of perfumery species belonging 

 to the Myrtaceae. 



1 For history of citral, see Tiemann ; Berichte, 31, p. 3278. 



2 Report of April, 1888, p. 20 : Oct., 1888, p. 17. 



3 Queenslander , Jan. 7, 1905. 



4 Chemist and Druggist, 1906, 68, 738. 



