1S8 EFFECTS OF FOSEST VEGETATION OX CLIMATE. 



lu a very iinportaut and valuable eommuuicatiou by Mr. 

 Joseph Bosisto, 31. P., one of the Commissioners of the Phila- 

 delphia Exhibition, to the Eoyal Society of Victoria, we find the 

 characteristics and sanitary value of the JEucalypti shown by 

 chemical analysis of their volatile products. 



The author says — " The Mallee country plays a very important 

 part in the climatic influences of Australia. # * * * * 

 The nightly and morning dews of the mallee country are frequent 

 in spring and summer. This is in part OTsHing to the suspension 

 of water in the air during the hot days from the river Murray 

 and its tributaries, as they pass for a considerable distance 

 through this scrub, but the greater amount of the dew moisture 

 is owing to the exhalation of the leases, for it must be remem- 

 bered that, although the surface soil is dry and hard, the roots 

 ofo down to the moist undersoil obtained from the salt-water 

 springs. During the severe droughts to which this country is 

 subject the trunks of these dwarf trees are full of moisture, but 

 so poor of sap constituents that in one of the species in par- 

 ticular, when the trunk is cut down close to the roots, and placed 

 in a bushman's panikin, a cool and refi'eshing draught of water 

 is obtained, to the great relief of a weaiy wanderer in this lone 

 and dreary scrub." 



Mr. Bosisto goes on to say that it is held, on the lowest calcu- 

 lation, that in New South ^^ales and South Austmlia the mallee 

 country is twenty times the area of similar country in Victoria, 

 and that '' 06,877,444,000 gallons of oil are held at one and the 

 same time in a belt of country over which the hot winds pass ; 

 and considerino; also that the same condition exists throuo^hout 

 the major part of Australia with the other JEucalypti as that 

 which exists in Victoria, we cannot arrive at any otlier conclusion 

 than that the whole atmosphere of Australia is more or less affected 

 by the perpetual exhalation of these volatile bodies." He quotes 

 the address delivered by Dr. Andrews, in December, 1844, before 

 the Eoyal Society of Edinburgh, in which he states that " volatile 

 oils, like phosphorus {i.e. in common with) have the power of 

 changing oxygen into ozone while they are slowly oxidizing." He 

 citss also Dr. Day, of Geeloug, whose researches on this subject are 

 Avell-known, and who has '" demonstrated that the eucalyptus oils 

 absorb atmospheric oxygen, transforming it into peroxide of 

 hydrogen." He concludes from the facts demonstrated in his essay 

 that " whatever change may take place in the condition of the 

 atmosphere, arising from the free and large supply of these 

 chemical bodies in the air, it is, from all known evidence, of an 

 invigorating and healthy jiature and character." "Death (he says) 

 lives where power lives imused, and were it not that such happy 

 and benign influences as those exerted by the eucalyptus vegetation 

 existed around us, indepe/i/lent of ourseJve.<i, we might mouni our 



