112 HYDRO CYANIC -ACID GAS FUMIGATION IN CALIFORNIA. 



Page. 



Scale, black, climatic conditions most favorable 76 



enemy of citrus fruits in California 7, 8-9 



fumigation : 59-60 



dosages with potassium c yanid 59-60 



sodium cyanid 89 



introduction of parasite. Scutellista cyanea, into California 2 



cottony-cushion. (See Icerya purchasi.) 



insects affecting citrus, effect of climatic conditions thereon 76-77 



fumigation dosages with sodium cyanid 89-90 



purple, climatic conditions most favorable 76 



enemy of citrus fruits in California 7,8 



fumigation, difficulty of destroying scale on fruit 56-57 



dosages with potassium cyanid 55-56 



sodium cyanid 89 



length of exposure 55 



two successive treatments 57 



red, climatic conditions most favorable 76 



enemy of citrus fruits in California 7, 9 



fumigation 57-58 



dosages with potassium cyanid 58 



sodium cyanid 89 



San Jose, fumigation of trees therefor 1 



yellow, climatic conditions most favorable 76 



enemy of citrus fruits in California 10 



fumigation 60-61 



dosages with potassium cyanid 60-61 



sodium cyanid 89 



Schinus molle, food plant of black scale \ 78 



Scutellista cyanea, drawback to fumigation against black scale 60 



effectiveness against black scale on pepper tree (Schinus 



molle) 78 



effect of fumigation thereon • 77-7 S 



parasite of black scale Saissetia oleii). introduction into 



California 2 



Sodium chlorid, action during generation of hydiocyanic-acid gas 87-88 



effect of presence in cyanids on yield of hydrocyanic-acid gas 



in fumigations 49-50, 87-88, 99-102 



cyanid. (See Cyanid of sodiuir-. 



nitrate, effect of presence in cyanids on yield of hydrocyanic-acid gas 



in fumigations 103 



Sooty-mold fungus. (See Fungus, sooty mold.) 



Stored products, fumigation 2 



Sulphuric acid, action on hydrocyanic acid 97-98 



analyses of samples used for production of hydrocyanic-acid 



gas 91-92 



cost 79 



in fumigation 41-43 



amount necessary 42—13 



proportion with potassium cyanid for best yield of hydrocyanic- 

 acid gas 93 



sodium cyanid for best yield of hydrocyanic- 

 acid ga ? 85. 93-96 



Supply cart for fumigation, cost 79 



equipment 22-23 



