20 Is Uie Eucalyptus a Fever-destroying Tree ? 



hand, but am credibly informed that it is at the lowest cal- 

 culation 20 times the area of ours — we have 96,877,440,000 

 gallons of oil held at one and the same time in a belt of 

 country massed together, over which the hot winds pass ; and 

 considering also that the same condition exists throughout 

 the major part of Australia with the other eucalypts as that 

 which exists in Victoria, we cannot arrive at any other 

 conclusion than that the whole atmosphere of Australia is 

 more or less affected by the perpetual exhalation of these 

 volatile bodies. 



What then is the probable physical effect ? The elements 

 composing the volatile oils from the eucalypti are three — 

 O., H., and C. 



Dr. J. H. Gladstone, of London, gives the following 

 formula to the eucalyptus amygdalina — C 10 H 16 ; to some of 

 the others the like or a multiple of that ; and to eucalyptus 

 oleosa (mallee) C 10 H 16 O. 



The sp. grav. of these oils at 60° F. range between 0-881 

 to 0-923. 



Such volatile bodies when existing in the atmosphere are 

 so minute and so diffusive, that they may be expressed as 

 the fragrant breath of the tree ; requiring thousands of its 

 compound particles to form one minim. Under such a 

 condition, they are in a state of preparation for a change in 

 their molecular condition. The researches of Schonbein and 

 others relating to the change the oxygen of the atmosphere 

 undergoes by electricity and by other known oxidising 

 agents, suggested a similar province for the aroma of plants 

 and flowers ; and in an address delivered by Dr. Andrews 

 last December, before the Royal Society of Edinburgh, he 

 states that " volatile oils, like phosphorus, have the power 

 of changing oxygen into ozone while they are slowly 

 oxidising." 



Unless some such change took place in the air, the aroma 

 of the oils of the eucalypti would be always present, and to 

 such an extent as to become quite unpleasant. Ozone, or 

 whatever may be the active substance in the atmosphere, is 

 known to act in a similar manner on iodide of potassium 

 and some other chemicals, and Dr. Day, of Geelong, whose 

 researches on this subject are well known, has demonstrated 

 that the eucalyptus oils absorb atmospheric oxygen, trans- 

 forming it into peroxide of hydrogen.* 



* Dr. Day, of Geelong, recommends as an excellent and very agreeable 

 disinfectant, deal sawdust, mixed in the proportion of about one ounce of 



