THE EUCALYPTUS.

Globe, Volume I, Issue 76, 28 August 1874, Page 4

THE EUCALYPTUS.

The Argus says : To M. Bosisto belongs the credit of having been the first to investigate and make public the numerous medicinal properties inherent in the foliage, and therefore in the whole structure, of the numerous varieties of the eucalyptus ; and we are glad to find him following up the inquiries which he has been prosecuting for so many years by endeavoring to ascertain the direct influence of these trees upon the atmosphere. In the south of Europe, in Corsica, and in the north of Africa, where they are being extensively planted in malarious districts, the eucalypti have obtained the title of " the fever trees," because they are found to counteract or neutralise the miasmatic poisons arising from stagnant water and decomposing vegetation. Wheresoever the gum tree flourishes, intermittent fevers disappear. As M. Piguier observes, " a tree which grows with incredible rapidity, which can pump up from the soil ten times its own weight of water in twenty-four hours, and which spreads about in the atmosphere camphorated antiseptic emanations, is bound to play an important part in the sanitary purification of miasmatic countries." At the Cape, as we are informed on the same authority, the climatic condition and the aspect of some unhealthy regions have undergone a complete change by the plantation of great numbers of the blue gum; and the success of similar experiments in Algeria has been so signal, that the director of the Jar din d'Ussai, in the capital of that colony, entertains the confident expectation that the great desert of Sahara will be reclaimed by the agency of the very trees which we are doing our best to eradicate irom their native habitat.

Mr Bosisto's investigations, as he described in the paper which he read before the Royal Society on Monday evening, have led him to form the following conclusions:—" That the desert scrub gums, after a winter of average rainfall, supply the air with a continuous and even quantity of aromatic vapour, and keep up a vigorous vitality throughout the summer; that a short season of rain, and a long dry summer, diminish the formation of oil, and so lessen the exhalation; but, on the other hand, the species tending seaward increase their quantity after a short winter." Thus it will be seen that, by a beautiful provision of nature, something like a constant and continuous supply of this healthgiving vapor is kept up, no matter what may be the fluctuations of the seasons. After entering into a calculation for the purpose of showing the enormous quantity of essential oils elaborated by the eucalyptus in a belt of country traversed by the hot winds, M. Bisisto proceeds to argue that the whole atmosphere of Australia must be more or less affected by the perpetual exhalation of these volatile substances. " From all that he could gather on the subject," he said, " he arrived at the conclusion that there was an active agency existing in Australian vegetation over that of other countries, the exhalation from which gave to the atmosphere an invigorating and healthy tone. After examining all the evidence, he came to the conclusion that the eucalyptus was a feverdestroying tree." In this opinion he is fully sustained by that of some of the iirst physicians and chemists in Europe, and it would be interesting to ascertain to what extent the introduction and growth in Victoria of zymotic diseases of a miasmatic type have been promoted and encouraged by the wholesale clearance of the indigenous timber which has taken place in and around our chief centres of population.