335 



Most of the rubber obtained Iro n vines is valued at a much lower 

 figure than the best known tree- rubbers, but this may well be due 

 to the adulteration (referred to above) by the nati\e collectors, 

 who put together the rubber of any vine producing it however bad, 

 and is doubtless also due to their carelessness in collecting : still 

 rubber vines have not as yet shewn themselves very tempting to 

 planters, 



VOLATILE OILS. 



The distillation of volatile oils from plants is in these days a 

 very important branch of chemical industry and the number of 

 plants from which volatile oils are obtained is very large, of these 

 products some are used for scents, others in medicine or for various 

 purposes in the arts. There are a considerable number of plants 

 growing, cultivated or wild, in" the Malay Peninsula which produce 

 these oils and probably there remain very many more to be exam- 

 ined and experimented with. At present the oils actually distilled 

 in the Straits are but few in number, and considering the expense 

 of the machinery required to distil on a large scale, perhaps this is 

 not to be wondered at; on the other hand as the Citronella and 

 Lemon grass oils, of Singapore, have been so well known for many 

 years, it is possible that the distillation of these and other useful 

 oils might be profitably increased and even done on a larger scale 

 than at present. It may therefore be of interest to enumerate the 

 local plants which produce oils of economic value and to give some 

 account of them, and in doing so I extract much of these remarks 

 from the work by GlLDERMEISTER & HOFFMAN, "The Volatile 

 Oils" written for the well known firm of SCHIMMEL & Co. of 

 Leipzig, and translated into English by E. KREMERS, a work which 

 gives a most complete account of distillation and the products 

 derived. The distillation of oils dates back from very early times, 

 and the methods employed were very simple but gradually im- 

 proved till within the last few decades there was a very rapid 

 development of the whole industry due at first to the use of steam 

 under pressure, and later to the great development of chemical 

 technology. 



The essential oils of plants are secretion products in the cells, 

 or intercellular spaces, or in spiral ducts in various parts of the 

 plants. In some cases the roots, in others, the stems, leaves, seeds 

 or flowers are- used. These parts if hard, require to be ground up 

 or crushed before being subjected to the distillation process. The 

 prepared material is put into the distilling apparatus and heated 

 by steam, the vapours saturated with oil-particles are condensed 

 in the coder and the distiilate consisting of water and oil is sepa- 

 rated and the oil eventually purified. To this account of distilled 

 oils, I have added some description of the method of extracting 

 the perfumes of flowers with the processes of maceration and 

 enfleurage, as it may be of interest to some readers as showing a 

 possible industry to which attention ht re has never been paid, and 



