8o4 



THE TROPICAL AGRICULTURIST. 



[May 1, 1884. 



of the low-gi'ade phosphates of North Oaroliua — had re- 

 volutionized the agriculture of the South. Then, again, 

 the increased cultivation of upland rice (which in many 

 parts of the South had almost supplanted the lowland 

 rice, which was long the only species cultivated) was a 

 recent development. Finally, the industrial botany of the 

 South, where there are more plants of interest to the 

 industrial chemist than in any other section of the country, 

 might well merit attention in New Buglaml. The chemistry 

 of the cotton-plant, however, offers many questions of 

 interest to us in a section of the country where one of 

 the products of the plant is made use of more than in 

 any other. 



The first point of interest is the e.Khaustiou of the 

 soil, which is the result of cotton-culture. The soil is the 

 farmer's bank-account, and he must use it carefully, and 

 draw only the interest : he must not take away from it 

 any valu:tble constituents mthout rejjlacing them. Man 

 is a dev:istator of the soil, and is continually drawing on 

 his capital ; so that regions which were once favorable 

 for the cultivation of certain plants become, in time, unable 

 to support them, unless the valuable constituents of which 

 the soil is robbed be returned to it. Tlie .speaker referred 

 to the fact that the region of wheat-production has been 

 gradually moving westward. 



The e.xhaustion of the soil, due to the cultivatiou of 

 various plants, may be seen from the following data in 

 regard to the composition of those plants: — 

 100 bushels of wheat contain — 



46 pounds phosphoric acid, 

 30 pounds potash, 

 125 pounds nitrogen. 

 100 bushels of corn contain — 



33 pounds phosphoric acid, 

 20 pounds potash, 

 06 pounds nitrogen. 

 1,000 pounds of tobacco contain — 



7 pounds phosphoric acid, 

 54 pounds potash. 

 The 480,000,000 bushels of wheat produced in this country 

 in 1880 contain — 



1,100,000 tons phosphoric acid, 



720,000 tons potash, 

 2,800,000 tons nitrogen, 

 these quantities being ten times as great as those con- 

 tained in all the manures used on all the crops in the 

 1 United States in that year. What must be the result of 

 this devastation of the soili' These valuable constituents 

 must be replaced, or the soil will become unable to su.stam 

 the repeated di-aughts upon it. Now, in regard to the 

 cotton-plant: one point of it, namely, the seed, has been 

 thrown away until within a few years; but its value as 

 a manure (containing, as it does, a large proportion of 

 the valuable constituents of the soil) has within ten years 

 been recognized, and it is now utilized very exten.sively 

 as a fertilizer. By this means the valuable constituents 

 of the soil are returned to it, and it suffers very little 

 exhaustion. The cotton-lint contain very little potash, and 

 does not impoverish the soil ; it is a product obtamed 

 almost entirely from the atmosphere. Herein lies the 

 cotton-producer's great adv.antage. By retiu-niug the seed 

 to the soil, he can cultivate year after year, with no 

 exhaustion of the soil, the most valuable product of the 

 cotton-plant. The advantage that cotton has in this respect 

 over such plants as corn, wheat, or tobacco, is evident 

 when the figures are referred to. showing the relative 

 amount of valuable constituents withdrawn from an acre 

 of the soil by these different pUants. Thus : — 

 1 bale of cotton (per acre) contains about 

 *6 pounds phosphoric acid, 

 2*1 pounds potash, 

 1'5 pounds lime; 

 30 bushels of wheat (per acre) contain about 

 15 pounds phosphoric acid, 

 105 pounds potash, 

 1 pound lime; 

 while tobacco is even more severe in its effects on the 

 soil, producing some 1,5(I0 pounds to the acre, and \vith- 

 drwing almut 130 pounds of lime, and nearly 100 jjounds 

 of potash :uid phosphoric aeiil. 



Notwithskmding the fact that cotton impoverishes the 

 BOil comparatively little, fertilizers are <'xtensively used in 



its culture. It was discovered, almost by accident, that 

 bhght and rust in the cotton-plant are due to the want 

 of alkalies in the soil: the observation having been made 

 that the salted mud from the creeks and bayous and 

 arms of the sea, if put on the cotton-fields, was a cure 

 for tho.se diseases. Accordingly, fertilizers have been and 

 are now imported in great quantities from Germany; and 

 the pho.sphatic deposits in our own States, prmcipally in 

 the Oaroliuas, have been largely developed, mainly through 

 the exertions of Dr. Kaveuel of Charleston. This extens- 

 ive use of fertilizers is also due to the fact that the 

 cotton-seed is found to be valuable of itself, anil is by 

 no means universally returned to the soil ; in which case 

 other fertilizers would be scarcely necessary. 



The cotton-seed is an egg-shaped seed containing a 

 kernel within an outside woody hull, the former dropping 

 out when the latter is cut in two. The kernel is the 

 source of the well-known cotton-seed oil, and is mashed, 

 rolled, stramed, and pressed m hydraulic presses ; the oil 

 running off, and the cake or meal remaining. The latter 

 contains more tat and more proteine than the cereals, 

 but has less starch, and all the ingi-edients are mixed in 

 less favorable proportions than in the latter; so that it 

 is not as much used, and commands a lower price than 

 it otherwise would. Cotton-seed meal should be used along 

 with starchy matters, and when so used its value will be 

 appreciated, and it will command a higher price than it 

 does now. 



The hull of the cotton-seed is woody, and seldom used 

 tor food, but is valuable as a composting material, being 

 rich in fertilizing ingredients. — Popular /Science Neics. 



THE ■RTEST INDIAN LIME. 



The flowering and fruiting by the Earl of Ducie, F.R.S., 

 of the Lime of the West Indies (Citrus medica var. acida), 

 affords an opportunity of making better known a fruit 

 which has been much misunderstood. I should premise 

 that the word Lime is promiscuously applied to fruits very 

 different to this, especially in British India, where the Sweet 

 Lijues of various forms are universally spoken of under 

 that name, and that all these, together with the AVest 

 Indian Lime, are varieties of the Citrus medica of Linuseus, 

 which includes the Lemon, Citron, sweet and acid Limes 

 of the East Indies, and the small globose-fruited plant here 

 figured (Cot. Mug. t. 6,745). C. Medica is so closely allied 

 to the C. aiurantiuni, Linn., which includes the sweet Orange, 

 the bitter or Seville Orange, the Bergamotte, &c., as to have 

 been classed with it, as forms of one species, by several 

 excellent authors, together with other fruits which do not 

 concern us here. 



The genus Citrus is essentially an Eastern one, and the 

 forefathers of Oranges, Lemons, Citrons, and Limes are 

 certainly Tropical Asiatic, and may be found (though whe- 

 ther always in their pristine condition as opposed to escapes 

 from cultivation is not easy to determine) in the hot val- 

 leys of the Himalaya, of the mountainous districts of East- 

 ern Bengal and of the Deccan. 



From Tropical Asia they have, in their numerous cult- 

 ivated forms, been transported into Africa, Australia, and 

 the New '\\^orld, where the Orange extends into the tem- 

 perate zone, and the Lemons also, but with less power of 

 enduring cold, whilst the small acid Lime seems confined 

 to tropical or subtropical zones; hence, I do i:ot find any 

 plant exactly answering to the hitter in the magnificent 

 work of Kisso and Poiteu, illustrating the South European 

 Oranges and Lemons, whilst in the floras of the East and 

 A\^est Indies it is always included. 



The first good account of it is by Kuniph {Hortus Am- 

 io!j!c)i,<(s, vol. ii., p. 107, t. 20), published in 1750. lb: de- 

 scribes it under the Latin name of Limonellus, a//a.s- Liinon- 

 tenius or thin-skinned Lemon, answering to the Malavnn 

 name of Limon Nipis (in Dutch, Liemis-Boom). as a spin- 

 ous bush with small leaves much brighier than those of 

 the other Lemons, small flowers with the odour of those 

 of the Lime of Martinique, five petals, spherical, smooth, 

 fruit the size of an Apricot, skin citron-coloured, extremely 

 thin, puljj greenish-white, gratefully acid, having a delight- 

 ful odour and taste. He .adds that it is found in all the 

 Oriental ishmds. but never in the woods, always near houses, 

 implying that it is not indigenous. The only author who 

 has definitely taken up Kumph's plant is Uasskarl, who, 



