12 
account of the delay in experimenting upon it, it was a very old specimen when 
analysed. I procured a small quantity of the milky juice (latex) of this species, 
and obtained it quite fresh. It was obtained in the spring by auger holes well 
through the hark. Whether a tree will yield any liquid at a particular time 
is uncertain, and can he ascertained only by tapping. It apparently in no way 
differs from the Moreton Bay fig juice (F. macrophylla) , so familiar to the people of 
New South Wales. It was of the consistency and colour of thick cream and 
perfectly homogenous when freshly exuded. It gradually separates in two layers— 
a creamy or grey-coloured portion and a brown liquid of hardly higher specific 
gravity than water. Both layers continue to darken in colour. Analysis of this 
milky juice, completed within a month of exudation, remains a desideratum. A 
specimen I sent to Professor E. H. Bennie, of Adelaide, was examined by him and 
Mr. Goyder.* 
The following letter! was written at my instigation to the Director of the 
Boyal Gardens at Kew, by the Minister for Mines and Agriculture 
You are aware that ever since the paper of Warren de la Rue and Hugo Muller ( Phil. Trans., 1860 ; 
Journ. Chem. Soc., 1862, p. 62 ; Watts’ Diet., ii, 646) spasmodic attempts have been made to extract the 
caoutchouc which is contained in the juices of our native figs, notably F. rubiginosa and F. macrophylla. 
The latest and most serious attempt to ascertain the chemical composition of these juices is a paper by 
Professor Rennie and G. Goyder, entitled, “ The Resins of Ficus rubiginosa and F. macrophylla.” 
(Preliminary Notice); Journ. Chem. Soc., lxi, 916. 
In order to satisfactorily ascertain whether extraction of the caoutchouc from these fig-tree juices 
can be profitably carried on in New South Wales, I am anxious to learn of the most approved method of 
dealing with juices of this class. I have read with interest the following articles in the Kew Bulletin :— 
(a) Lagos Rubber ( Ficus Vogelii, Miq.); November, 1888, p. 253. 
(b) West African Rubbers; March, 1889, p. 63. 
(c) Lagos Rubber ; May, 1890, p. 89. 
These all refer to Ficus juices, and it is perhaps a fair inference that our trees should be dealt 
with similarly to the West African ones, and that the resulting products are similar. 
I gather from the above reports that the experiments of Mr. A Ivan Millson at Lagos, in the matter 
of extraction of the India-rubber (caoutchouc) from the Ficus juices, are not altogether satisfactory, and 
some friendly criticism was given by the India-rubber, Gutta-percha and Telegraph Works Company of 
Silvertown (page 258, November, 1888). But neither in this nor in subsequent issues of th e Kew Bulletin 
do I find explicitly stated what is the method recommended for the treatment of the Ficus juice. At 
certain seasons of the year the juice (latex) of our native figs flows freely and abundantly if the tree be 
cut with an axe. This juice could be readily collected in kerosene tins. I shall be glad if you will kindly 
inform me how this juice should be treated, and in what quantity, and in what condition, should the 
sample be that I sent to London, with the view of obtaining expert opinion in regard to the probable 
commercial value of the article. 
By this post I send you a specimen of Ficus juice, and also one of crude caoutchouc “ obtained 
by evaporation,” by a correspondent of this Department. They are small specimens, and I have not 
broken the seal since I have received them, as fermentation may be set up. I do not know whether they 
will be of any assistance to you in giving me the advice I ask for, as I presume you will require to see the 
caoutchouc prepared according to the method you will suggest; meantime any information will be much 
appreciated. 
* Rennie (E. H.) and Goyder (G.)—“ The Resins of Ficus rubiginosa and F. macrophylla (Preliminary Notice).’ 
Journ. Chem. Soc., lxi, 916. 
+ “Native Juices and Caoutchouc (India-rubber).” Agricultural Gazette, N.S.W., November, 1894, page 759. 
