272 HORTICULTURIST'S RULE-BOOK. 



Soluble phosphoric acid 1.54 Organic nitrogen . . 0.86 



Reverted phosphoric acid 5.92 Nitrogen as nitric acid 0.33 



Insoluble phosphoric acid 10.99 Insoluble matter . . 13.64 



Potassium oxide ... 3.46 



36. Oak-Leaves. 



Moisture at 100 C. . 9.601 Potassium oxide . . . 0.549 



Organic matter . . . 83.360 Phosphoric acid . . . 0.058 



Mineral matter . . . 6.840 Nitrogen . . . . . 0.930 



Ferric oxide .... 0.027 Soluble silica .... 0.018 



Calcium oxide . . . 0.548 Insoluble silica . . . 4.333 

 Magnesium oxide . . 0.267 



37. Seaweed. (Two samples.) 



i. ii. 



Moisture at 100 C 12.05 14.96 



Nitrogen 1.66 1.28 



Phosphoric acid 0.44 0.17 



Potassium oxide 3.81 0.36 



Calcium oxide . . 2.73 3.86 



Magnesium oxide 1.48 1.30 



Sodium oxide 11.75 8.40 



Chlorine 6.40 5.28 



Insoluble matter 7.73 0.78 



38. Tobacco-Stems. 

 Water 13.47 



Organic and volatile matters (containing nitrogen 1.93) . 70.85 



Ash (containing phosphoric acid .53) 15.68 



100.00 

 39. Dissolved Bone-Black. 



This material is a superphosphate prepared by treating refuse 

 bone-black from sugar refineries with oil of vitriol, which ren- 

 ders nearly all the phosphoric acid soluble in water. 



Soluble phosphoric acid 14.55 



Reverted phosphoric acid 2.39 



Insoluble phosphoric acid 0.20 



