112 HYDEOCYANIC-ACID GAS FUMIGATION IX 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 leery a 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 
