Issued October 25, 1912. 



U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF ENTOMOLOGY— BULLETIN 'No. 90. 



L. O. HOWARD, Entomologist and Chief of Bureau. 



HYDROCYANIC-ACID GAS FUMIGATION 

 IN CALIFORNIA. 



I. FUMIGATION OF CITRUS TREES. 



By R. S. WO GLUM, M. S. A., Special Field Agent. 



II. THE VALUE OF SODIUM CYANID FOR FUMIGATION PURPOSES. 



By R. S. WOGLUM, M. S. A., Special Field Agent. 



III. CHEMISTRY OF FUMIGATION WITH HYDROCYANIC-ACID GAS. 



By C. C. McDONNELL, Chief, Insecticide and Fungicide Laboratory, 

 Miscellaneous Division, Bureau of Chemistry. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 



1912. 



