THE EUCALYPTUS IN THE FUTURE. 665 



growth is wonderful. Saplings fifty feet high, and but ten years old, 

 are not remarkable. It is declared that seed sown in Jamaica at an 

 elevation of 5,000 feet, in 1870, had in 1876 attained a growth of fifty 

 feet. We have with our own eyes witnessed throughout an entire 

 summer a growth of an inch a day. No one understood so well as 

 Baron von Muller the nature and capacities of the Eucalyptus. He 

 more than all others has made the world acquainted with it. With 

 him was a scientific faith that this was the world's tree of promise. 

 In this tree of Australia he saw the means with which to obliterate 

 from the hydrographic map the rainless zones, to clothe with wood 

 the desolate ranges of Tunis, Algeria, and Morocco, and render habi- 

 table parts of the Great Sahara, by indefinitely expanding the oases, 

 to restore fertility to the Holy Land, to give rain to the Asiatic 

 plateau, or the desert of Atacama, and furnish timber and fuel to 

 Natal and La Plata. 



None better than the baron, however, knew that, while able to 

 stand great heat, these rapidly-growing eucalypti cannot resist great 

 cold, and without these home conditions we must not expect of them 

 their home achievements. Even at home the tribe does its best with 

 its semi-tropical members. And there is a great range of variety un- 

 til we meet even the Alpine species, of slow growth and very modest 

 altitude. Skill and patience may do much ; but in our country, except 

 in a few favored spots, little can be hoped of the semi-tropical varieties 

 north of latitude 30, until acclimatization shall have been effected. 



But it is claimed for the eucalypts that their presence is hygienic, 

 or sanatory, especially in malarial regions. That the E. globulus has 

 earned by fair experiment its name of fever-tree, as a preventive, 

 seems now to be settled. Its rapid growth must make it a great 

 drainer of wet soils, while its marked terebinthine odor may have its 

 influence, and it is highly probable that the liberation of this essence 

 into the air stands connected with its generation of ozone. But, 

 whatever the sanatory activities of the eucalypt may be, the fact is 

 squarely settled that spots in Italy, uninhabitable because of malarial 

 fever, have been rendered tolerable by the planting of E. globulus, 

 and it is believed that a more plentiful planting would nearly if not 

 quite remove the difiiculty. A military post is mentioned in Algeria, 

 in which the garrison had to be changed every five days, such was 

 the virulence of the malaria. A plantation of eucalypts cleared the 

 miasma nearly away, and rendered unnecessary the frequent changes 

 of the garrison. In this case 60,000 trees were planted. 



But the eucalyptus has not a few medicinal virtues. Its oils and 

 essences are antiseptic. Diffused in the sick-room, they purify the air 

 and generate ozone. Already they have taken their places in the 

 materia medica as very important internal medicines. The leaves 

 contain the essence eucalyptol, and a resinous solid containing a bitter 

 principle not yet understood, and which seems to afford the antifebrile 



