502 



THE TROPICAL AGRICULTURIST. 



[December i, 1882 



The Ekman Fibre Patent continues attract 

 much attention in England. We hear that Ml'. 

 Boiitledge, the great authority on the treatment of 

 bamboo, having given Mr. Ekman some of the thin 

 bamboos, was gi'eatly pleased with the pulj) made from them 

 by the new process. He went next to the works with 

 large bamboos, watching them being liquified into pulp. 

 It is expected that in all probability he wLU adopt the 

 Ekman process. Mr. Routledge has done so much 

 for the advancement of the fibre trade, not always 

 with success to himself, that his interest goes far to prove 

 the value of the Ekman process when so good an 

 authority takes it up. 



Plumbago.— A piece of black lead appears to have 

 been named on much the same principle as that fol- 

 lowed in naming the Speaker of the House of Com- 

 mons. The Speaker is a man who does not speak ; the 

 black lead is a substance which contains no lead. It is 

 true that apiece of black lead presents character.^ which, 

 at tirst siglit, are strongly suggestive of a metal ; but 

 it is easily shown that these characters are only 

 superficial and delusive. If we split open a lead pencil, 

 and extract the thin rod which forms the axis of the 

 cedar cylinder, we obtain a body which resembles a 

 metal, inasmuch as it processes a dark iron-gray or 

 lead color, coupled with exactly that kind ot luster 

 which we generally regard as characteristic of metallic 

 bodies. The surface of a compact piece of metal always 

 preents a peculiar brilliancy, due to the fact that 

 much of the light which falls upon the surface is 

 thrown back instead of passing into or through the 

 substance ; in other words, the light incident upon the 

 surface is neither absorbed nor transmitted to any 

 considerable extent, but is almost wholly reflected or 

 scattered. Now, there are but very few substances, 

 except metals, wliich possess such a condition of sur- 

 face as to produce this metallic sheen. Iodine is one 

 of these noii-metallio bodies that look like a metal, 

 and black le.id is another. It is mainly in conse- 

 quence ot the metal-like luster a black lead tbat the 

 material is so largrly employed as a polishing .\gent. 

 When the housemaid rubs the powdered suljstauce 

 upon the cast-iron grate or fender, she produces a re- 

 flecting surface which has a metallic appearance ; and, 

 at the same time, the thin coutiug ■which is thus ap- 

 plied serves to protect the underlying metal from rust. 

 In like manner, though for a different reason, black 

 lead is extensively used for polishing certain kinds of 

 gunpowder, especially the coarse grained powder em- 

 ployed for blasting in mining operations. The powder 

 is placed, with the finely-divided black lead, in re- 

 volving barrels, and the grains receive a glaze or 

 varnish which protects them from absorption of 

 moisture. Any conclusion as the metallic nature of 

 black lead which may have been suggested by the 

 lustre and color of the mineral, is likely to be rudely 

 shaken on noting its specific gravity. By merely 

 poising a piece of black lead in the hand, we may 

 observe how light it is, compared with ordinary me- 

 tallic bodies. In fact, thb specific gravity of black 

 lead is but little above 2— that is to say, the mineral 

 does not weigh much more tliai) twice its own bulk 

 of water. Advantage is sometimes taken of this com- 

 parative lightness in dressing black lead for tlie market. 

 It frequently happens that a rock may contain scales 

 of plumbago distcminated througbout its substance, 

 so as to form what has been called " black lead ore." 

 In such a case it is possible to sepiarate the two 

 .substances by crushing or stamping the ore, and allow- 

 ing the fine fragments nii.xed witli water to flnw over 

 a mechanical contrivance, in which the light scales of 

 black lead and the heavier stony particles roui^hly 

 sort themselves l)j vir;ue ol this difierei^ce of density. 

 It is scarcely conceivable tli.it these light nal.s of 

 plumbago can contain a metal so heavy as lead. — 

 .\! rnmfactvrer and Builder. 



The Madras Cinchona Gardens.— Tlie Gardeners' 

 Chronicle reports that Professor Lawpon is about 

 to vacate the Professorship of Botany atj Oxford, to 

 assume the post of Superintendent of the Government 

 Cinchona plantatione, Madras. Professor Lawson will 

 carry on analyses of bark .no doubt in connection with 

 experiments in culture. His annual reports will be 

 looked for with much interest. 



Vine Culture. — The vine no doubt grows in 

 Colombo, but it does not pay the troulde and time 

 spent upon it. A good vine is a rarity in ''olombo : 

 its favorite homp in Ceylon is Jafl'na, whence large 

 supplies of grapes are regularly received in CoIoiuIjo. 

 There it flourishes and yields" large returns. It is 

 found almost in all houses in the towu of Jafi'n«, but 

 it is to he regretted that its cultivatiim is not much 

 attended to, and some old trees winch had existed 

 from the time of the Dutch* have lately disappeared and 

 no attempt has been made to find successors to them. 

 The manure u.sed is, cow dung, dried and simple. It 

 is applied immediately after pruning. At no time was 

 vine cultivation on a large scale carried on in Jafl'na, 

 and why it has not been done is .surprizing, — Cor. 



Refined Cottonseed Oil as a SuB.STiTtrrE for Lard. 

 — At the Inst regular meeting of the Baltimore Gro- 

 cers' Exchange the committee on cottonseed oil as a 

 substitute for lard, composed of Messrs. T. A. Agnew, 

 A. N. Crowder, and W. A. Oliver, submitted their 

 report as follows : — Your committee deem it not out 

 of place, in speaking of cottonseed oil, to give some 

 account of the method of saving or picking the crop 

 of which it is so important a factor. The cotton, 

 with the seed imb^ded in its midst, and adhering to 

 it, is picked from the bolls with the fingers, placed, 

 in baskets and carried thence to the gin-house. Here, 

 the lint or stape is separated from the seed, and the 

 latter are transported to the oil mills, where they 

 always command the cash. The greatest care is taken 

 to prevent them from getting wet after being ginned 

 as they easily ferment :ind spoil in this condition. 

 Connected with the machinery of the mill is a deli- 

 cate and costly attachment known as the " Decorti- 

 cator," into which being first thrown, the seeds are, 

 by a subtle proccRS, relieved of the hull or outer 

 covering ; thus stripped, the kernels pass on into the 

 jaws of the crusher, a machine of tremendous power, 

 where the oil is expressed. In its crude form it then 

 goes to the refinery, where, by repeated processes of 

 heating, the refuse is thrown off, and the product 

 assumes the limpid light yellow appearance so fan. iliar 

 to good judges. There is absolutely n'^ foreign sub- 

 stance used in any of the places of manufacture, so 

 at least your committee has been informed and be- 

 livees, and the "refined article" is the native product 

 ot cottonseed, pure nud simple, with its ordinary im- 

 purities removed. The very important question now 

 arise^i, whether this oil is really what it claims to be, 

 a healthful and uutrious article of diet, and whether 

 it can supply the place of lard. Your committee have 

 used due dilligence in arriving at facts, and beg leave 

 to report that all evidence goes to confirm the pre- 

 vious good reports. From the most reliable sources 

 comes testimony that cannot he questioned. In the 

 South, citizens of high standing, among whom are 

 business men. physicians and scientists, unite in 

 declaring that the use of cottonseed oil for the table 

 is conductive to health, and that it can supply the 

 place of lard perfectly. Here in Baltimore, whi're for 

 five months the test has been applied patiently .and 

 thoroughly, your committee ba\'e at their disposal the 

 names ot many well known citizens who have became 

 couvertsto the " new dep.aitiire. " —Oil nndPaint Remew 



* Can our correspondent prove that Jaffiia vines have been 

 cultivated for over S'l years P We do net doubt the fact, 

 but would like to know if there is any local authority on the 

 subject. Cordiner mentions the grapes of the north. — Ed. 



