THE CITRINE ODOURS. 79 
is about 68° to 78° F. Under 60° F. the flowers are blighted. 
An ordinary tree in America is said to yield from 2 to 10 lbs. of 
flowers, generally about 7 lbs. ; they are often collected on canvas 
cloths spread under the trees. The most fragrant flowers are 
those which fall in the early morning. Orange-flowers produced 
in the extreme southern borders are believed to possess a stronger 
odour and more oil; the difference is accounted for in this 
manner :—“ In the tropics the trees do not begin to bear very 
much until about twenty years old, while in this country they 
begin at about seven; the development is more rapid, the tree 
more vigorous, and it is reasonable to suppose a better development 
of odour in the flower.’? The writer in the Journal above referred 
to states that “the flowers are more fragrant, and the fruit more 
juicy, but not so sweet as in some other countries ;” further, that 
“ collected flowers placed in the direct sunlight lose all their odour 
in the course of two days, in diffused daylight they retain it for at 
least three days, and, in a dark humid atmosphere, the odour is 
quite distinct after one week. When bruised they lose their odour 
in half the time stated. The flowers hermetically sealed up in 
tin canisters are known to have retained their odour unimpaired 
for nine months.” 
All the sorts of Citrus may be propagated by seeds, cuttings, 
layers, and grafting. The object of raismmg plants from seed is 
either to obtain new varieties or stocks for grafting. Shaddock 
stocks are the strongest, and next to these the citron. At Genoa 
and Florence citrus trees are grown in a strong yellow clay, which 
is richly manured, a soil which is considered by the first Italian 
gardeners as the most suitable. For growing citrus trees in boxes, 
the French gardeners recommend a fresh lozm containing a third 
of clay, a third of sand, and a third of vegetable matter, which has 
lain a long while in a heap. An equal bulk of half-rotten cow- 
dung to be then added and the whole allowed to remain till the 
next year, when it is to be twice turned over. The succeeding 
year it is to be mixed with one half its bulk of decomposed horse- 
dung, and turned over two or three times. The winter before 
using it is to be further enriched with a twelfth part of sheep-dung, 
a twentieth of pigeon-dung, and a twentieth of dried night-soil. 
The compost recommended by Henderson, an English culti- 
vator, consists of one part of light brown mould from ground that 
