302 . INDEX. 



Page. 

 Oak family of plants, ....... . . . . 50, 51 



Oats, climate and soils for, . . - 169, 170 



Oats, cultivation of, .. . . 169, 170, 254 



Oil of vitriol, formation of, .-. . . . 8 



Onion maggot and fly, 226 



Open drains, objections to, . . . . 137 



Opposite electricities, . . ...... . . . 74 



Orchis family of plants, .......... 54 



Ores, elements in form of, . . . . . . . 74 



Organic manures, division of, . 107, 108 



Organs of plants, 45, 46, 47 



Original types, modification of, 150, 151 



Osiers, cultivation of, . . . . 196, 197 



Osmotic action, . : . 18, 58, 72 



Ox and horse labor, ........ . . 238 



Oxalic acid in sorrel, . . . . 66 



Oxidation or rusting, . ...-._* . . . 7 



Oxides, how formed, ...... .~ ... 7 



Oxygen, action of, 90 



Oyster-shells, value of, . . . . .. . 101 



Parsnips, deep ploughing for, . . 143, 186, 214 



Pasturage, mixture of grasses for, 135, 189, 190, 191 



Pea culture and varieties of the, 175, 176 



Pea weevil, remedy against the, . . . 176 



Pears, time to gather, . ... . . 252 



Peat, mode of using, . . . . . . . V . 125, 126 



Petal of the flower, . . . . . . .;. .. . - 46 



Phenomena of the atmosphere, . . . . . . 31 



Phosphate of lime, ........... 61 



Phosphates in plants, . . . . * . . . . . 65 



Phosphorus, appearance of, . . . . 61 



Pine family of plants, ......... . 54 



Plaster of Paris, ......... 15,96,102,117 



Planting, depth of, . . . . 154, 162 



Planting, time of, 153, 162 



Planting trees, effect on climate of, 95 



Plant lice on wheat, . , . . . . . . . . 231 



Plants, absorption and exhalation of, 40,146 



Plants, d-v-l&amp;lt;,i,inent of, . - . . 50,147,177,213 



Plants, origin of, . . . .... . . . 147, 149, 150 



Plough, use of the, . 142, 155, 159, 162 



Plough the subsoil, 143, 144 



Ploughing, operation of, 130, 131, 132, 143, 144, 159, 184 



Plumule of the plant 48, 49 



