286 



The Supplement to the Tropical Agriculturist 



THEOBROMA AND CASTOR OILS. 



At the second evening meeting of the Phar- 

 maceutical Society of Great Britain held at 17 

 Bloomsbury Square, London, W.C., on December 

 14 (the President Mr. J F Harrington in the 

 chair) Mr. C E Sage, bu.c, f.c.s., read his 

 paper on the 



FIXED VEGETABLE OILS OF THE PHAKMAUOPCEIA. 



Mr. Sage's lecture lasted about an hour and 

 a half, and was illustrated by a large number 

 of lantern-slides dealing principally with the 

 machinery employed in oil-pressing. In the 

 course of it he spoke of 



THEOBEOMA OIL. 



The lecturer gave a very full account of the 

 preparation of cacao. The beans undergo fer- 

 mentation before being roasted, the latter being 

 the most important part of the manufacturing 

 process. After being cleaned by machinery the 

 nibs are ground, and the pasty mass, containing 

 50 to 57 per cent of oil, is put into a prest. 

 The oil which exudes is coloured and is sub- 

 mitted to filtration in a hot room, when the 

 white product familiar to pharmacists is ob- 

 tained. The oil used in this country is pressed 

 in England, which, said the lecturer, is a guar- 

 antee of its quality. He would like to see the 

 rubric "expressed in Great Britain" restored. 



CASTOR OIL. 



There are numerous varieties of Ricinus com- 

 munis, the seeds of which yield castor oil. 

 The size of the plant varies according to the 

 country in which it is grown ; in India and 

 the United States it attains a considerable size. 

 The oil was very largely used as lamp oil in 

 India before the introduction of mineral oils, 

 but now that the local demand has lessened 

 a good deal of the seed is exported. Hull, the 

 centre of the caetor oil trade, produces from 

 300 to 350 tons of oil every week. After describ- 

 ing the older processes as practised in India, 

 Mr Sage gave details of how the oil is pressed 

 in this country. The first step in cleaning the 

 seed is to pass them over a magnetic separator 

 to collect iron nails and similar extraneous 

 metallic matter. The testa is next removed by 

 slight crushing and the seeds pulped. The pulp 

 is then dealt with in a variety of ways, the 

 "clodding" press being chiefly employed in 

 Hull. The first pressings give the pharmaceu- 

 tical castor oil if good sound seed has been 

 used. An alternative process is to form the 

 meal into cakes for packing into another kind 

 of press. The oil as pressed is refined. This 

 consists of heating it with fuller's earth and 

 filtering by means of a filter-press. The press 

 cakes are afterwards steamed and re-pressed, the 

 product being a lubricating oil. Extraction by 

 benzol is also practised, The lecturer gave the 

 following data regarding castor oil : 



Iodine Free Saponification 



Castor Oil. No. Acid. Number. 



Pharmaceutical .. 83'5 0'94 17B - 7 

 First .. 84-6 1-08 175 9 



Second .. 86'0 3'8 172'0 



The lecturer concluded with a reference to soya- 

 bean oil, which is at present "occupying the 

 attention of the trade Press." In the 



Discussion, 



Mr EM Holmes — said: Enormous quantities of 

 castor oil are employed for lubricating purposes 

 owing to its peculiar viscosity and its cheapness. 

 The Indian trade is largely in the hands of one 

 man. Castor oil free from taste and purgative 

 principle is used in China as salad oil Although 

 soya-bean oil has only been made within the last 

 three years, the beans have been in the museum 

 for the last twenty or thirty years. The oil is 

 employed in the manufacture of margarine. 



Mr E T Bkewis— after referring to the inter- 

 esting nature of the paper, said soya-bean oil 

 has been pressed for many years, but has not up 

 to now found many outlets in this country. 



Professor H G Gkeenish — said the lecture 

 would be much appreciated by students on 

 account of its practical character. Is it neces- 

 sary, he asked, to spend so much time in prepa- 

 ring the seeds before pressing ? He once saw a 

 working process, in which the castor seeds were 

 pressed whole, and understood that other seeds 

 were treated in the same way. In regard to the 

 formation of oil in the seeds, the oil forms in 

 globules in the protoplasm ; but although the 

 problem is not yet solved, the evidence goes to 

 show that it is not produced from the mannite. 



Mr Sage — in reply to Professor Greenish — said 

 that he knows of one mill producing 25,000 tons 

 of castor oil a year where the seed undergoes 

 no preparation before pressing. The cakes are 

 extracted with benzol, and after removal of the 

 poisonous principle are used for cattle-feeding. 

 In regard to the physiological processss that 

 lead to the formation* of oil in plants, his im- 

 pression was that bacteriological action played 

 as active a part as enzymes. — Chemist and Drug- 

 gist. 



"DIE-BACK" OF HEVEA BRAZIL- 

 IENSIS: FATAL CASES. 



THE LATEST PERADENIY A CIRCULAR. 



The latest Botanic Gardens circular, recently 

 to hand, consists of a treatise by Mr. T. Petch, 

 the Government Mycologist, on " Die-Back of 

 Hevea Brasiliensis." The subject is exhaustively 

 dealt with, and the writer's observations and 

 suggestions will be found of great value to all 

 rubber planters. A serious aspect of the disease 

 is that, whereas, a few years ago, it was essen- 

 tially one which attacked trees from one to two 

 years old only, it was last year found on several 

 estates on trees from nine to 14 years old, in 

 some cases killing them with astonishing rapid- 

 ity. The disease kills back the tree froru the 

 top ; although its earlier stages generally at- 

 tract attention in the case of young trees, they 

 are seldom noticed on old trees. The fungus 

 which begins the disease attacks the leading 

 green shoot ; the place attacked becomes dark 

 brown, and this discolouration gradually ex- 

 tends over the whole shoot, while the leaves 

 fall olf as the fungus reaches them. If the dead 

 shoot is then cut off, the tree sends up a new 

 leader from the uppermost remaining bud, and 

 the disease is thus got rid of with very little 

 damage to the plant. If it is neglected, the 



