264 



CASSELL'S POPULAR GAEDENING. 



Crab, Gloria Mrindi, Hambledon Deux Ans, Hoary 

 Morning, London Pippin, Lord Derby, Norfolk 

 Bearer, Golden Keinette, Nonsuch, Koyal KuBset, 

 Small's Admirable, Striped Beaufin, Tower of Glam- 

 mis, Waltham Abbey Seedling, Wormsly Pippin, 

 Winter Majetin, Eymer. 



Apples for "Warm Iiocalities. — Dessert. — 

 Devonshire Quarrenden, American Mother Apple, 

 Cox's Golden Drop, Cornish Aromatic, Golden 

 Reinette, Margil, Melon Apple, Pitmaston Non- 

 pareil, Eibston Pippin, Ashmead's- Kernel, Claygate 

 Pearmain, Cornish GUliflower, Court Pendu Plat, 

 D'Arcy Spice, Lamb Abbey Pearmain, Golden 

 Harvey, Golden Pippin, Sam Young. Kitchen. — 

 Lord Suffield, Cellini, Cox's Pomona, Emperor 

 Alexander, Lemon Pippin, Lord Derby, Mere de 

 Menage, CalviUe Blanche d'Hiver, Waltham Abbey 

 Seedling, AHriston, Brabant BeUefleur, Lane's 

 Prince Albert, Royal Russet. 



Apples for Cooler Localities and Scot- 

 land. — Dessert. — King of the Pippins, Oslin, Ravel- 

 ston. Red and Yellow Ligestre, Cockle Pippin, 

 Court of Wick, Court Pendu Plat, Golden Reinette, 

 Red Astraohan, White Paradise, Sykehouse's Russet, 

 Nonsuch. Kitchen. — Tower of Glammis, Warner's 

 King, Yorkshire Greening, Keswick Codlin, Bed- 

 fordshire Foundling, Brabant BeUefleur, Manks' 

 Codlin, Dutch Codlin, Hawthomden, Rymer, Royal 

 Russet, Nelson Codlin. 



MANITEING IN THEOET AND 

 PEACTICE. 



Bt JOHir J. Willis. 



NITRATES AS FLANT-FOOD. 



ALTHOUGH plants are unable to assimilate the 

 free nitrogen of the air, experiments demon- 

 strating the fact that nitric acid is capable of per- 

 iectly supplying vegetation with nitrogen have been 

 carried out by Boussingault. 



Two seeds of a dwarf Sunflower {Belianthm argo- 

 phyllm), -were planted in each of three pots, the soil 

 of -which, consisting of a mixture of brickdust and 

 sand, was freed from aU nitrogenous compounds by 

 ignition and washing with distilled water. To the 

 soU of pot A, Fig. 7, nothing was added save the 

 two seeds and distilled water, with -which all the 

 plants were watered from time to time. With the 

 soU of pot B were incorporated small quantities of 

 phosphate of lime and bicarbonate of potash, in 

 •order that the plants growing in it might have a 

 soluble mineral supply. Finally, the soil of pot c 



received the same mineral manures as pot b, and, in 

 addition, a small quantity of potassium nitrate (salt- 

 petre). 



The seeds were sown on the 5th of July, and on 

 the 30th of September the plants had attained the 

 relative size and appearance seen in the diagrams, 

 where they are represented in one-eighth of their 

 natural dimensions. 



Nothing can be more striking than the influence 

 of the nitrate on the growth of plants, as exhi- 

 bited in this experiment. The plants A and b arc 

 mere dwarfs, although both carry small and imper- 

 fectly developed flowers. The plant c, on the con- 

 trary, is scarcely smaller than the same kind of plant 

 would "be when grown under the best conditions of 

 garden culture. 



We gather from Boussingault's experiments, as 

 from those of Lawes and Gilbert, that without some 

 compound of nitrogen in the soil, however much 

 there may be in the atmosphere, vegetation cannot 

 attain any considerable luxuriance, notwithstanding 

 all requisite ash constituents are present in abun- 

 dance. 



The plants suppKed with nitrate of potash as- 

 similated sixty-six times as much nitrogen from the 

 manure as was acquired by a and b from external 

 sources. 



The Soil as a Source of Plant-food.— 



The next question to consider is the amount of plant- 

 food contributed natui'aUy by the soil itself in a 

 virgin state. 



We learn by the study of geology that the earth 

 upon which we live has passed through great 

 changes, extending over vast periods of time. 

 All soils have been produced by the disintegration 

 of rocks, which, through the influence of rain, frost, 

 and air, have gradually crumbled to pieces. The 

 diversity of soils greatly depends upon the character 

 of the primitive rock from which they have been 

 derived. SmaU particles of pulverised rock, by the 

 help of living animals and of vegetable gro-wth, 

 have been broken down into continually smaller 

 fragments, and lastly into a dust-like powder; 

 and this substance, when mixed -with decay- 

 ing animal and vegetable mctter, forms a soil 

 capable of growing plants. The elements taken 

 from the soU. in its virgin condition were returned 

 to it on the decay of the plants which it had 

 nourished, or on the death of the animals which fed 

 upon the plants produced. 



Each year, as time went on, a certain portion of 

 the vegetable growth died, leaves and branches fell, 

 and portions of the roots decayed, causing the sur- 

 face soil to become rich in carbon and nitrogen. The 

 atmosphere of the soil, which at first difeered but 



