Dr. N. L. Britton, Director-in-Chief. 



Sir: I have the honor to submit the following report 

 for the year 1909. 



No extensive changes have been made in the laboratories 

 or laboratory equipment during the past year. Necessary 

 supplies for student work conducted at the Garden have 

 been purchased from time to time but these have not 

 necessitated the expenditure of any large sum of money. 

 As a temporary arrangement, a corner in the chemical 

 laboratory has been used as a mounting room during the 



Dr. W. J. Gies, consulting chemist of the Garden, has 

 continued his weekly visits to the laboratories during the 

 year to supervise the work of students carrying on in- 

 vestigations of problems in biological chemistry. 



Insect Pests and Plant Diseases 



The regular spraying work for insect pests with scalecide 

 and whale-oil soap has been continued as usual. The 

 equipment for this work has been extended by the addition 

 of a spraying apparatus which will make it possible to reach 

 trees to a height of fifty feet. In addition to the remedies 

 mentioned above, arsenate of lead has been tried for biting 

 insects. The elm trees were sprayed once as a preventative 

 against the attacks of the elm leaf beetle. While it was 

 too late in the season to secure the best results, the remedy 

 seems to have been effective in destroying the insects and 

 an earlier application of this remedy another year will 

 doubtless yield very satisfactory results. 



The chestnut disease is prevalent as usual and no remedy 

 has been found for the disease. Numerous other fungous 

 diseases have been noted during the year but none of 

 sufficient importance to deserve special mention. 



