Tor. XII. No. 302. 



THE AGRICULTURAL NEWS. 



375 



RUBBER INDUSTRY. 



VEGETABLE OILS. 



QUALITY OF PARA RUBBER FROM 



VARIOUS PLACES. 



A number of samples of Para rubber have lately been 

 ■reported on in the liidletin of the Lnjierial Institute (July- 

 September 1913). These came from Ceylon, India, Southern 

 Nigeria, British Guiana and Papua. The following is 

 a summary of the report. 



The samples from Ceylon consisted of a number of 

 biscuits and represented rubber prepared from a row of trees 

 tapped at intervals of one, two, three up to seven days 

 respectively. A few of the biscuits were rather weak but, on 

 the whole, jiood. Chemically, the rubber was of very good 

 quality (96 per cent, caoutchouc), but it is of interest that 

 the rubber obtained by tapping at intervals of three to seven 

 days contained a little more caoutchouc than the rubber 

 obtained by tapping every day or every other day. 



The samples received from Burma showed considerable 

 variation for plantation rubber. In general, the percentages 

 of resin and protein were a little higher than is usual, and 

 in these cases the amount of ash was e.xcessive. 



The Southern Nigerian biscuits were composed of well 

 prepared smoked rubber, and possessed very good physical 

 properties. The brokers report on these samples seems 

 eminently satisfactory. The biscuits were classed as fair 

 average quality and valued at about -is. \Qd. per H). in 

 London, with fine hard Para at 4s. lOlrf. per R , and smoked 

 plantation sheet at 4s. 8rf. to 4s. llrf. per lb. It is stated 

 that consignments of similar character would realize very 

 good prices in the market. The difficulty at present is, of 

 course, to say what is 'of similar character'. 



BRITISH i^UI.^N.^. 



A sample of Para rubber biscuits and one of scrap 

 rubber were received from British Guiana. The biscuit 

 rubber was rather weak, but considering the age of the trees 

 (four and a half years, 18 inches girth 3 feet from ground), its 

 physical properties must be regarded as quite satisfactory. 

 The scrap rubber was also rather weak. Chemically, the 

 biscuit was very good, but the scrap contained rather more 

 resin, protein and ash, and consequently, the percentage of 

 f-aoutrhouc was lower. The biscuit rubber was valued at 

 about 3s. per fc. in London and the scrap rubber at about 

 2s. 6(/. per lb . with fair average quality plantation sheets or 

 biscuits at 3.^. \\d. to 3s. 2Ul. per tb., and fine hard Para at 

 3«. %\d. per ft. 



llevea '>rasiliensis has only just come into bearing in 

 the territory of Papua, but the report on samples of this 

 rubber received at the Imperial Institute in November 1912 

 shows that Papua can produce rubber equal in quality to 

 that of'fine hard Para. The rubber was in the form of large 

 thin sheets of pale brown colour; it was clean and very well 

 prepared. The physical properties of the rubber were 

 excellent, whilst analysis showed the quality to be exceed- 

 ingly good also. Examined by brokers, this rubber was 

 valued at 4s. per Si. in London, with fine hard Para at 

 -3s. 1 Id. per lb., and average plantation sheets and biscuits 

 at 3s. lOJd. to 3,s. U^d. 



The prospects of the cultivation of Hevea 'jtusiliensis 

 in Papua, therefore, appear to be exceedingly promising. 



PULZA OIL. 



Under this name a considerable industry is carried on 

 in the Cape de Verde Islands in the oil obtained from the 

 seed of Jativphu Vun-as, a Euphorbiaceous plant, commonly 

 known throughout the West Indies as the Physic nut. 

 According to information received from Kew, about 350,000 

 bushels of the seed are gathered and exported annually to 

 Portugal where the oil extracted is called purqueira oil and 

 is used principally for burning. In Briti.sh commerce it is 

 usually known as seed oil. 



The expression of the oil is performed in the dry, oa 

 seed slightly crushed; 1,000 lb. of seed gives 040 lb. kernels 

 which yield 260 lb. of oil. The industry is carried on most 

 extensively at Lisbon. The decorticated seed contains about 

 52 per cent, of this oil, which is a semi-drying oil and u.sed 

 for soap and candle making. The cake is unsuitable for 

 cattle food but worth about £3 per ton (1904) as manure. 

 The value during 1904 of the oil was £14, .5s, per ton (see 

 Bulletin of the Imperial Institute, September 1904, pp. 170 

 to 171, also i'jid 1912, p. 62). At the present time the 

 price would be much higher. 



In connexion with the value of the seeds as cattle food, 

 attention has recently been drawn in the Journal of the 

 Board of Agriculture (October 1913) to the occurrence of 

 some cases of poisoning in Germany from the employment 

 of the seeds of Jatropha curcas. The information in ques- 

 tion refers to experiments both with the oil and seeds and 

 reviews the cases of poisoning. The observations are sum- 

 marized as follows: Curcas seeds contain (1) a poisonous 

 agent, curcin, which has no effect on blood globules in I'ifro, 

 but which does harm to blood vessels in I'iiv and, above 

 all, probably has a toxic eti'ect by lodging in important brain 

 centres (in the same way as ricin); (2) curcas oil: the 

 poisonous properties of this are due to curcanic acid produced 

 in an analogous manner to crotonic acid. In consequence of 

 its content of curcanic acid it is one of the strongest drastic 

 substances known, and when curcas seeds are taken internally, 

 the curcanic acid causes entero-gastritis both in man and 

 animals. 



The above information is believed to be of special interest 

 in the West Indies in view of the wide distribution of 

 Jatropha curcas. In conjunction with the production of other 

 oils or oil-bearing vegetable matter like cotton seed, it might 

 be found possible to develop a pulza oil industry in tie West 

 Indies. Further information on the subject will be given in 

 the Agricultural News as it becomes available. 



NOTE ON A LEMON GRASS OIL 

 FROM FIJI. 



A volatile oil has recently been distilled from a plant ia 

 Fiji identified at Kew as Cymbopogon roloi-atus, Stapf, 

 a species which had not hitherto been used commercially for 

 the production of volatile oil. The oil has the remarkable 

 property, very unusual in an essential oil, of retaining its 

 characteristic odour after the soap in the making of which it 

 is used, has been kept for a considerable time. 



It appears that in the 1913 experiments, 1,117 stools 

 gave 2,988 lb. of grass from which lO'Ol R). of oil were 

 obtained, or at the rate of 43"4 fib. of oil per acre. The 

 actual return per acre varies, but in Fiji the difference 

 between the value of the oil obtained and the cost of 

 distilling it should be at least £2 per acre per cutting. Two 

 cuttings a year may be depended upon, whilst three may be 

 made unless dry weather sets in for some time. 



