112 HYDKOCYAXIC-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 cyanid 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 77-78 



parasite of black scale (Saissetia olese), introduction into 



California 2 



Sodium chlorid, action during generation of hydrocyanic-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 sodium.) 



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 42-43 



proportion with potassium cyanid for best yield of hydrocyanic- 

 acid gas .' 93 



sodium cyanid for best yield of hydrocyanic- 

 acid gas 85, 93-96 



