EUCAL YPTUS. 139 



other works conducive to better sanitary conditions. 

 Drainage works, intensive cultivation, better human quar- 

 ters, better drinking water, etc., etc. 



In Southern California we have no endemic malarial 

 disease, unless there be mild forms in far interior points 

 where the nights for sufficiently long periods are warm 

 enough. We have consequently been unable to look over 

 the local field for the effects of Eucalyptus trees on 

 malaria. In Central California, however, it is claimed that 

 plantations of Eucalyptus globulus have diminished or 

 stopped malaria. Delano has been cited as a striking in- 

 stance of this. We know that a number of species, nota- 

 bly the fast growing ones, have a drainage power in them- 

 selves. This power is well recognized here and results in 

 the planting of Eucalyptus trees about cesspools and their 

 being cut down along orchard lines from which they draw 

 the moisture. Cesspools that overflowed and caused uneasi- 

 ness and care have been kept down or dry by Eucalyptus 

 trees. This is one way in which this tree might amelio- 

 rate malarial conditions. 



Another is by its essential oil contained in quantity in 

 the foliage of many of the species; these leaves contain an 

 oil, etc., that is, in concentrated form, fatal to all insect and 

 bacterial life. It occurred to me that the constantly falling 

 leaves from species highly charged with Eucalyptus oil 

 might disinfect the ground and ground water about them. 

 I have found but little encouragement for such an opinion 

 in my rather superficial experiments. 



Prof. A. J. McClatchie kindly examined several jars of 

 water into which leaves of Eucalyptus globulus were 

 placed at the Throop Polytechnic Institute. Ordinary bac- 

 teria were found by him in great quantity in the jars at 



