JO 2 



THE TROPICAL AGRICULTURIST. 



[October i, jSBz. 



he see anything like the piercing of a leaf. We trust, 

 therefore, we have not the deadly " mosquito blight " 

 amongst us, although we suppose that, on the jirinciple 

 of " where the carcase is, there will the eagles be 

 gathered together," we must expect its advent some 

 day. Except "red spider," the "tea bug" is the 

 worst enemy of cultivated tea. In certain seasons the 

 yield of particular estates, .sometimes whole districts, 

 has been reduced by one-fourtli, one-third, and even 

 one-lialf, by the ravages of these insect pests, known 

 to Indian planters under the rather iuappropi'iate 

 generic term " blight." The rains of the monsoon 

 have been so heavy that even the cockchafer beetles 

 disappeared, and in India it is believed that heavy 

 rains wash away the "bug" and the "spider." In 

 any case neither insect nor external fungus was ob- 

 served, although we suppose it would be imphilo- 

 sophical to recognize fermentation in the leaf tissues 

 except as the result of the presence of certam forms 

 of fungi ? 



What renders our surprise and disappointment so 

 extreme at the development of a malignant disease 

 in the leaves of JJl. (jlobubis, is the enthusastic estim- 

 ate generally formed of the antiseptic powers of those 

 very leaves, with their powerful volatile oil. Here 

 is Baron von Mueller's summmg-up in his elaborate 

 description of E. i/lol/idus contained in his great work, 

 " Eui:alyptofiriijihia " : — 



" We have as ytt no accurate patholojjic data on the 

 effect of the exhalation of Eucalyptus-forests on 

 phthisic patients ; but I Huticipate, tliat in the same 

 mauuer as the air of dense woods of Pines is apt to 

 stay the inflammatory processes in diseases of the 

 respiratory organs, so the vapors of our Eucalyptus- 

 forests, the odor of which we so readily perceive and 

 recognize, will likewise arrest the progre.5s of these 

 sad diseases, more pirtieuhirly in tlieir tarlier staijes, 

 and proliably more so than sea-air, notwithstanding 

 its pureness, the atoms of bromine and iodine carried 

 with it and the increased ozone, which it evolves. 

 Indeed I should assume, that sanitarian dwellings 

 could nowhere on the whole earth be provided for 

 phthisic patients more auspiciously an 1 more hope- 

 fully, than in mountains clothed with Eucalyptus- 

 forests in extri-tropical Australia and at elevations 

 (v.irjjin^ according to latiuide from 1,000 to 3,000 

 feet), where the sliylitlv rarifiid air of a very niodev- 

 ate humidity [lervadcd by Eucalyptus vapor together 

 with the comparative equability of the temperatuie 

 would ease tlie res|iiration greatly. This assumption 

 is largely based on ihe facts, th it no other gregari- 

 ous trees in the world evolve essential oil so largely 

 as our Eucalypts, unless perhaps snme ol' the most 

 teretimthiue I'lncs of cnlder climes, and that thus is 

 afforded mo>t copiously an oily volatile emai-aiinn, 

 befitted to absorb and comlfuse oxj'gen into oz lue, 

 the most powerfully vitaliziig, oxydizing and therefore 

 also chemically and therapeutically disinfecting ele- 

 ment in naturH's whole range over the globe- 



" Our Blue Gum-tree has jn the whole exercised 

 already on regions of the warm temperate zone a greater 

 influence, scenic, industrial and hygienic, than any 

 other single species of arboreous vegetation ever reared 

 nnywhee, even Pines or Oaks or other classes of 

 leading trees not excepted- Thus it has transformed 

 the features of wide formerly tiee-less landscapes, has 

 alrfaHy afforded in many places timber and fuel for 

 rapidly incrcasiig settlements, and rendered also many 

 a miasmatic locality permanently habitible. The sanit- 

 ary influence of Eucalyptus- vegetation was surmised 

 by more than one of the early Australian settlers, 

 who however were reluctant to place their conjectures 

 on public record without positive investigations and 

 final proof- Mons. Kamel touched with a few words 

 on this subject (Revue maiitime et coloniale) in 1861, 

 but Sir William ilacarthur was perhaps the hrst to 



argue, very many years ago, that our freedom from 

 ague here was mainly due to our extensive myrtace- 

 ou« vegetation, in which the Eucalypts aie prominent, 

 although species of Milaleuca, Leptospermum, Pasckea 

 and 601116 allied genera are also gregarious in many 

 parts of Australia. The incontestable sanitary eflFect 

 of these prevailing Myitaceaj throughout Australia, 

 except in some of the tropical coast-tracts, must be 

 ascribed to a complex of causes : 1st, the ready and 

 copious absorption of humidity from Ihe soil by 

 Eucalypts and closely allied trees ; 2ndly, their cor- 

 responding power of exhalation, much greater than that 

 of many other kinds of trees ; 3rdly, especially the 

 evolution of peculiar highly antiseptic volatile oil ; 

 4thly, the disinfecting action of the dropping foliage 

 on dicayiug 'rganic mat'er in the soil, Eucalyptus- 

 leaves themselves not causing any noxious effluvia 

 through their own decomposition. Thus during macer- 

 ation, for artistic skehtonizing. Eucalyptus- leaves, 

 unlike almost all other kinds of foliage, give off no 

 disagreeable odor, as first observed here by Mrs. Dr. 

 Lewellin. The disinfecting and deodorizing virtue of 

 the tree being unquestionable, it has even been placed 

 in the wards of continental hospitals, a measure initiated 

 by Drs, JMosler and Goeze of Greifswald and here 

 insisted on by Dr. Alexander Buettner. The fresh 

 bruised leaves can with advantage be employed for 

 the dressing of wounds to prevent or subdue seplic 

 inflammation, especially when no other remedies are 

 at hand. Possibly the Blue Gum-tree is evtfn a better 

 scavenger of back-yards than a weeping willow, and 

 in so far safer as it does not intrude into the found- 

 ations of buildings and leaves no putrefying foliage. 

 Indeed the sewage-question of cities in the warm 

 temperate zone would become very much simplifled, 

 if each house had at its rear the evergreen Eucalyptus 

 tree. Mr. Th. Taylor found that albuminous com- 

 pounds could be preserved in water, which by mere 

 maceration of leaves of 1]. globulus had absorbed some 

 of their oil and perhaps other preservative particles, 

 a few drops of oil added to water serving the same 

 purpose. Other kinds of volatile oils act very variously 

 in this resp'ct. To Bacteria and other micro- 

 organisms Encalypius-oil proves as fatal as Pheuic 

 Acid ; hence also, as Tayli^'r observed, it may bo 

 injected into the veins and arteries of cadavers for 

 purposes of preservation. Flesh of any kind is as 

 well preserved by Eucali pus-oil as by Creosote, while 

 beef sprinkled with it will dry hard withnut putre- 

 factiou. This writer is inrdined to attribute the 

 hj'gienic action of the oils of Euca-lyptiis and Pines 

 simply to their high oxydizing power exemplified in 

 the decomposition ol miasmata. He recommends 

 Eucalyptus-oil to be applied as an admixture to 

 dressings in Gangrene. [See Report of the Depart- 

 ment of Agricultuie, Washington, 187(5, pp. 82 — 86.) " 

 The Baron makes no reference to the possibility of 

 the leaves becoming diseased and being the source of 

 disease in other vegetation. , A. M. F. 



OUR COFFEE CROPS :— SECONDARY AGEN- 

 CIES AND THE FIRST CAUSE. 

 We call attention to the letter of "P. T. L." on 

 page 311, and we must, in jitstice to ourselves, add 

 a note to what this able writer says, to indicate 

 our sympathy with the man who, in a somewhat 

 similar crisis, says what the late General Skobeloff 

 said when his attacking force was almost annihilated, 

 "I blame no man; it is the will of (4od." On that 

 position, we, who are not agnostics, must fall back, 

 when, having done our best to understand and regul- 

 ate secondary causes, we are compelled in a species 

 of despaii' to give the problem up and fall back ou 



