TWENTIETH ANNUAL REPORT 51 



PURIFICATION OF AIR IN BUILDINGS AT PARK. 



In an attempt to purify the foul air and eradicate animal 

 odors in the different buildings at the Park, your committee 

 authorized the installation of ozone machines. These machines 

 are operated by electricity and the consumption of current is 

 about the same as for one electric light bulb. The results have 

 been most gratifying. Nine machines have been installed 

 during 1915, at a cost of $75 each, chargeable against the Main- 

 tenance Fund. 



MEDICAL DEPARTMENT. 



The general health of the mammals has remained good 

 throughout the year, the deaths occurring principally among 

 the small mammals and South American monkeys. 



Except where an immediate autopsy was necessary to deter- 

 mine the cause of death in order to safeguard our collections, 

 all animals have been turned over to the Prosector's Department. 

 It has been necessary to destroy an increasing number of ani- 

 mals from our original stock on account of old age. During 

 the coming year it will be necessary to destroy a number of 

 animals whose usefulness as exhibition specimens is past, owing 

 to general debility resulting from old age. Many of these 

 animals were of adult age when received at the Park, and have 

 been on exhibition continuously for more than a dozen years. 

 With some of these animals, especially where the specimen is 

 rare, and difficult or impossible to replace, it is often difficult 

 to decide just when it has reached such a state of debility as 

 to justify its merciful destruction. 



The new Animal Hospital which has been greatly needed 

 for many years is now nearly completed, and should be ready 

 for service about March, 1916. This building will provide excel- 

 lent facilities for the isolation and treatment of medical and 

 surgical cases, and at the same time by the prompt removal 

 of suspicious cases of illness, reduce the danger to the healthy 

 animals from infectious diseases. 



FORESTRY DEPARTMENT. 



The usual amount of general maintenance work, such as 

 cleaning of walks, lawns and buildings, the collection and dis- 

 posal of garbage, refuse, manure and ashes, the general upkeep 



