JULY. Illuminating Power Amount of Impurity. in Standard Sperm Candles. Sulphuretted Ammonia per 100 Sulphur per Hydrogen. feet, grains. 100 feet, grains. 1 18.6 None 0.8 16.4 2 17.6 „ 1.2 19.2 3 ... „ 0.0 19.1 4 ... „ 1.2 19.6 6 ... „ 0.0 20.4 7 17.6 „ 0.8 20.1 8 17.6 „ 0.8 20.2 9 17.4 „ 1.0 20.2 10 17.4 „ 1.0 20.3 11 17.3 „ 0.0 19.3 13 17.5 „ 1.8 19.6 14 17.3 „ 1.0 20.3 15 17.5 „ 0.0 20.5 16 16.6 „ 0.0 19.5 17 16.6 „ 1.0 19.4 18 16.7 „ 0.6 19.4 20 16.9 „ 0.2 19.4 21 16.8 „ 0.0 16.0 22 17.0 „ 0.0 14.4 23 17.2 „ 0.0 16.0 24 Not received 25 16.8 „ 0.0 16.5 27 16.7 „ 0.0 16.0 28 16.7 „ 0.0 16.3 29 16.5 „ 0.4 16.2 30 16.6 „ 0.6 26.4