80 ODOROGRAPHIA. 
has not been cropped or manured for many years, one part of peat- 
earth such as is used for growing heaths, one part of rotted hot- 
bed dung, and one part of rotted leaves of trees, mixed well together. 
Though orange-trees grow exceedingly well in large boxes in a 
conservatory, yet to produce the finest crop of fruit they should 
be planted in the ground against the back wall of a narrow house, 
and treated like peach-trees. In this way they may be propagated 
quickest from cuttings of strong young shoots or pieces of two- 
year-old wood from 10 inches to 2 feet in length, covering with a 
hand-glass and giving a gentle bottom heat. They will strike in 
seven weeks or two months. The citron is the most easily struck 
and the freest grower. Budding and grafting seedlings or cuttings 
grown in England under glass or in warm climates in the open air 
may be performed at any time when the sap is in motion. Trees 
raised from seed and grafted in England are found to bear the 
cold better than imported trees. 
Gallesio, in his ‘ Traité du genre Citrus,’ has given a synopsis 
of the forty principal sorts cultivated in Italy. In the ‘ Histoire 
Naturelle des Orangers,’ by Risso, of Nice, and Poiteau, of Ver- 
sailles, 169 sorts are described, and 105 of them figured ; they 
detail 4.2 sorts of sweet orange, 32 sorts of bitter and sour orange, 
5 bergamots, 8 limes, 6 shaddocks, 46 lemons, 17 citrons, and 12 
other sorts. A great number of hybrids produced by accidental 
cross-fertilization are known, and details of very curious hybrids 
produced experimentally are described by Gallesio in his ‘ Storia 
della Riproduzione Vegetale’ (Pisa, 1816). 
The essential oils of each variety of Citrus vary in perfume, and 
the products of the flower, leaf, and fruit of the same tree varies. 
The oil distilled from the fresh flowers, termed Neroli or Oleum 
Neroli, is much esteemed for its delicate perfume. Oil of Neroli 
being so valuable when pure, and so difficult to obtain pure, the 
following extracts, from so high an authority as Flickiger and 
Hanbury’s ‘ Histoire des Drogues,’ may be translated with ad- 
vantage :—“‘ The Neroli of Citrus aurantium, var. Bigaradier, is 
slightly brown in colour, bitter in taste, and neutral to litmus. 
The specific gravity of a pure sample obtained from Mr. Warrick, 
of Nice, was found to be 0°889 at 11°C. Mixed with alcohol it 
presents a brilliant violet fluorescence, quite distinct from the blue 
fluorescence of a solution of quinine. This phenomenon is very 
evident when a little spirit of wine is poured on the surface of the 
