INDEX. 
Page. 
Acids, mineral, action on cyanids and hydrocyanic acid 96-99 
Ammonia formed by decomposition of cyanid 102-103 
Ammonium sulphate, residue from decomposition of cyanid 102-103 
Bordeaux-distillate emulsion, injury through fumigation to trees sprayed there- 
with 72-73 
Cactus. (See Opuntia engelmanni.) 
Carboy with handles to facilitate pouring acid in fumigation 25, 26 
Cart. (See Supply cart.) 
Chart for dosage (see also Dosage schedule). 
how to use it 34-37 
Chemicals in fumigation 40-51 
amount in very small dosages 48 
mixing 48-49 
most economical proportion 47-48 
proportion when sodium cyanid is used 85 
Chemistry of fumigation with hydrocyanic -acid gas 91-105 
summary 104-105 
Chrysomphalus aurantii. (See Scale, red.) 
citrinus. (See Scale, yellow.) 
Citrus fruits, insect enemies in California 7-10 
orchards in California, extent and character 6-7 
trees, fumigated, appearance 73 
presence of old scales thereon 74 
fumigation. (See Fumigation of citrus trees.) 
greater susceptibility of some varieties than others to injury from 
fumigation 67 
gum disease. 66 
sprayed, injury to those fumigated 72-73 
unhealthy, effects of fumigation thereon 66-67 
Climatic conditions (see also Meteorological elements) . 
effect on scale insects of citrus 76-77 
Coccinella calif ornica, effect of fumigation thereon 77 
Coccinellidse. (See Ladybirds.) 
Cold, effects in fumigation of citrus trees 70-71 
Cyanid, " American, ' ' not potassium cyanid but sodium cyanid 84 
ammonia formed by its decomposition 102-103 
" German " 84 
of potassium, analyses of samples used for production of hydrocyanic- 
acid gas 92-93 
comparison with sodium cyanid for general fumigation. . 90 
cost 79 
dosages of sodium cyanid in comparison with dosages of 
former 88-89 
in fumigation 40-41 
proportion for best yield of hydrocyanic-acid gas 93 
strength of sodium cyanid expressed in terms thereof. . 85 
107 
