230 “SCIENCE OF THE STUDY OF TREES, . PART II ; 
4. Denmark. 5.Sweden and Norway. 6. Russiaand Poland. 
7. Switzerland. _ 8. Italy, Greece, Spain, and Portugal. 
b. America. 1. North America. 2. Mexico. 3. South America. 
c. Asia. 1. Asia Minor. 2. India. 3. China. 4. Japan. 
d. Australia and Polynesia. 1. Van Diemen’s Land. 2. New South 
Wales. 3. New Zealand. 
B. Commercial Statistics. Trees and shrubs are objects of commerce: in 
their young state, as plants ; and in their more matured state, as timber, 
fencewood, fuel, bark, leaves, fruit, seeds, &c. 
a. Nursery Commerce, domestic and foreign. Some trees and shrubs, 
from being in little demand, are scarcely known out of private gar- 
dens, or public botanical establishments; others are cultivated in the 
nurseries, some very generally, and others only partially. Under 
the head of Commercial Statistics, we shall notice whether the spe- 
cies is cultivated only in some nurseries, or generally ; and we shall 
give the prices of plants of the smallest size fit for transplanting, and 
also of seeds when they are to be procured : in London ; in the exten- 
sive nurseries of Messrs. Baumann at Bollwyller on the Rhine, as a 
situation central for France, Germany, Switzerland, and Italy; and 
in New York, as a central situation for North America. 
b. General Commerce, domestic and foreign. Under this head it will be 
our object to notice such trees, or their products, as are in general 
transfer in the internal commerce of the country; and such, also, as 
are exported or imported. Some woods, as the pine, fir, oak, elm, 
&c., are in general commerce; and so, also, are some other products, 
such as oak bark; but the timber of the spindle tree and the labur- 
num, the inner bark of the holly, and the flowers of the elder bush, 
enter into the commerce only of particular places. What we shall 
state respecting either the foreign or domestic commerce of trees 
and shrubs, will be limited to what relates to the trees and shrubs of 
temperate climates ; that is, to those species which are described in 
this work. 
Such is the beau idéal of the desiderata which we intend to keep in view, 
when describing each species ; but we by no means bind ourselves to have, 
in our descriptions, a separate heading for each of the paragraphs in this 
Chapter ; on the contrary, it will generally be found, that all that we have to 
say respecting each species will be included in the paragraphs entitled, Iden- 
tification, Synonymes, Derivation, Engravings, Specific Character, Varieties, 
Description, Geography, History, Properties and Uses, Soil and Situation, 
Propagation and Culture, Accidents and Diseases, and Statistics. 
All the matter included under the first four headings, as being of less inte- 
rest to the general reader, we have placed in small type, in order that it md 
occupy but little space, and be easily passed over by those who do not wis 
to read it. We have also placed in small type the whole of the matter re- 
lating to species which have not been seen by us; and also to those which are 
only half-hardy, and require either to be planted against a conservative wall, 
or otherwise to receive some kind of protection during the most severe 
weather in winter. We have done this, though we consider what relates to 
the species which require some protection, as likely to prove one of the most 
interesting parts of our work to many gardeners and amateurs (for what 
would the enjoyments of gardening be, without the elegant cares of exotic 
culture ?), in order that those who take an interest only in hardy trees and 
shrubs may distinguish, at a glance, what belongs to them. 
