September i, 1S84.] THE TROPICAL AGRICULTURIST. 



18 = 



MANGOSTEEN OIL. 



The Becd of the Garcinia Tndica yields ■■ rich oil of 

 great purity. This tree is indigenous to the western districts 

 of India, Itgrowsin the region known as Concan, hetween 

 Goa and Daman, The Corps Greti Industrie/a describes as 

 follows the in"!.- in which the oil is obtained: — 



The seeds are dried in the sun during several days, and 

 are then crushed ;iiicl boiled in water. The oil which es- 

 capes rises to the surface, and in cooling forms a solid 

 crust. The yield is about Id per cent. The product in 

 its rough state requires to be purified, and for this pur- 

 pose is nulled in a steam bath, being afterwards filtered. 

 It is then perfectly transparent, of a straw color, and at 

 a temperature of 5"5°C. it forms a crystaline mass. 



This on is principally composed of stearic acid, with lesser 

 quantities of myristic and oleic acid, the whole combined 

 witli glycerine. It easily saponifies, and produces a fine 

 hard soap. [fis soluble in ether, and slightly so inrectified 

 alchol. If kept for too long a tine' i* assumes s rancid 

 and disagreeable odour and a brownish appearai 



It is found in the bazaars of India in the form of 

 oblong pieces measuring about three and a quarter inches 

 by one and a-half inches, ami weighing about four and a 

 hall' ounces. It is whitish, solid, dry and friahle, hut greasy 

 to the touch. It is employed in India for the purpose of 

 adulterating ghee, and recently Europeans have employed 

 in for pharmaceutical preparations. Its relative scarcity 

 does not allow of its use in the manufacture of soap and 

 candles, for which purpose it would he a superior article. 

 — Independent Journal. 



DISEASE OF PALMS. 



In the course of last summer we received from different 

 persons diseased plants of Oorypha and Phoenix, the leaves 

 of which were covered with brown patches. Heir Professor 

 De Bary, of Strasbourg, had the kindness to examine them, 

 and the following is the result, which we now publish :— 



"The diseased plants of Oorypha anstralis which yon 

 sent to me at the end of October were a long time under 

 examination by us before we could say anything about 

 them. That is the reason the answer has been so long 

 delayed. The browned dead portions contained all sorts of 

 fungi (moulds), but quite preponderating, as furtl 

 animation taught, was the species Pestalozzia, related to, 

 and similar but not identical with P. macrospora, Ces. If 

 the brown spots were made moist the spore-forming i 

 of the mould appeared on the surface in the form of black 

 patches, as the enclosed sample indicates. When the 

 moulds were distributed on healthy leaves that were cut 

 from the plants and kept in a moist state the fungus 

 pierced them and caused their death. According to the 

 degree of dampness so spread the destruction ever a greater 

 or a lesser area. Whether the Fungus is capable of killing 

 perfectly healthy seedlings thai are not kept too moist 

 was not determined. From those plants which were sent, 

 and which were grown on, all died except one. This has 

 a leaf on which the Pestalozzia has appeared, and which 

 is now partially dried up. The dying symptoms made no 



further progress in winter, and the plant is pushm, 



sturdy new foliage. Healthy seedlings of Phicnix dai tyli 

 fera and of Ohamserops were not attacked by the fungus 

 even under quite moist culture under hell-glasses. On sac- 

 charine mixture and similar inorganic substances the Pes- 

 talozzia grows extraordinarily luxuriant. What most con- 

 cerns us is the destruction of the fungus. The attacks 

 are most probably invited by the not quite normal form- 

 ation of the Oorypha seedlit I least assisted here- 

 by."— A. De Baby in Deutsche Gartner Zeitvng. 



THE ECONOMICAL PURIFICATION OF OILS 



FOR CULINARY USES. 

 The Corps Gras Industriels remarks that linseed, colza, 



poppy, and other nils are often used to replace otl 



higher value. The disagreeable odour of some of thi se oils 

 (even when freshly'madi irises from the sei 



not being fresh, and consequently not yielding a fin 

 The disagreeable savour is principally due to the presence 

 in fatty aci.ls. small quantities of albuminoid substances, 

 i 1 1U8 bodies, and other impurities, finely divided are 

 24 



also suspended in the oils, tending to form acid and volatile 

 tions which give to the oils a di i dour 



and savour. 



Experiments made with coconut oii have proved that 

 the aend savour can be removed by washing with carbonate 

 ol soda. No process can remove its peculiar odour, hut 

 as this is by no means unpleasant, there is no necessity 

 tor doing so. 



The simplest way of removing the disagreeable savour is 

 to melt the "ii on a hath ol water, and to add a solution 



of 2 per cent of carbonate ol' soda I 10 pi • cent of 



olilornivt of sodium in 50 per cenl of water. After] 

 turned it dining some time, the fleecy precipitate is re- 

 moved by filtration. If in shaking the oil (together with 

 alcohol to which a small quantity of litmus has keen added) 

 there is still produced an arid reaction, the operation is 

 recommenced. 



The filtered oil is then washed with hot water, or boiled 



in i ' ; t water, in order to remove the fist trace of - n 



and albuminoid substances, rtr. Salt is used to prevent 

 the oil forming an emulsion wfth the solution ol carbonate 

 of soda, and to raise the temperature during ebullition. 



Neither the washing of the oil with borax, nor its treat- 

 ment with chlorine or bichromate of potash and hydro- 

 chloric acid produce any effect. 



It is, however, evident that a better product can be 



,,lil - 11 1 "ith fresh seed and by purifying ihe oil immediately. 



! itting the oil into tin vessels, or into glass vessels 

 hermetically closed.it can be preserved without becoming 

 rancid. 



The above process is applicable to almost all vegetable 

 oils, and to cotton oil if the quantity of carbonate of 

 soda is proportionate to the quantity 'of free acids con- 

 tained in the oils. The advantages' which are possessed 

 by other reagents have nut yet heen determined I 

 dependent Journal. 



AGRICULTURE IN PARAGUAY. 

 Consul Baker, of Buenos Ayres, states that one of the 

 most valuable crops of Paraguay is tobacco; in 1829, its 

 production amounted to only 2,675,0001b., while in I860, 

 the crop amounted to 15,000,000 lb. ; hut the war with the 

 allies almost ruined this source of wealth. It has, how- 

 ever, somen hat overed its importance, the exports alone 



last year amounting to 8,975,0001b. A large proportion of 

 the crop is annually worked up into cigars, a branch of 

 industry which is almost, entirely in the hands of the 

 worn. n. The tobacco planted in Paraguay originally 

 came from Havana, with the exception of a particular kind, 

 which is called in Paraguay blue tobacco, peti-hobi/, the 

 origin of which is unknown. The favourite leaf is a yellow 

 tobacco, peti-para, grown chiefly in Villa Rica, which poss- 

 • i about ti percent of nicotine. Sugar-can. is another 

 of the important agricultural products of the country— a 

 plantation of which sometimes lasts, without any care or 

 necessity of replanting, for ten or twelve years. II is 

 estimated that one acre of the cane will produce about 

 250 gallons of molasses. Rice also is extensivelj cultiv- 

 ated, and also Indian corn. Coffee is largely grown, and 

 is regarded by some as the crop of the future. The crop 

 which is most esteemed by the Paraguayans is the mandi- 

 oca, it being with them an article of prime necessity. 

 taking the place of wheat-flour in the family household; 

 the tuber is also used as a vegetable. The quantity of 

 land now under cultivation is very small, compared 'with 

 the amount before the war with the allies, the great scarcity 



of kil ivrs in the country very seriously retarding the 



development of the agricultural interests. ' At the present 

 tine there are 450,650 acres of land under cultivation, oi 

 which 210,000 are under corn, and 126,000 under man. lie, ia. 

 In Paraguay the cotton plant grows spontaneously, grow- 

 ing very rapidly, and lasting for ten or twelve years. The 

 orange groves are scattered indiscriminately all over the 

 country, the plantations attaining all immense growth, and 

 the forests are everywhere full of the orange trees from 

 the casual dropping of the seed. The fruit has come to 

 be not only an almost indispensable article of food, but 



its annual exports exceeds 10, 000 ol oranj 



destined for Buenos Ayres and Montevideo. The mosl 

 important production of the country is stated to be Para- 

 guayan tea or yerha mati, which in former years, lo- its 



