MEDICAL AND CECONOMICAL BOTANY. 
HE Vegetable Kingdom contains, among a large quantity of plants 
of no known importance to man, various useful species employed in 
medicine, the arts, or in the many branches of domestie economy. 
The principal part of those which can be brought by teachers in Europe 
under the notice of students, or which, from their great importance, deserve 
to be among the earliest subjects of study, are mentioned in the following 
pages, where they are arranged in the manner proposed in the ‘** Vegetable 
Kingdom”’ of the author, with the sequence of matter departed from in a 
few instances, when it was believed that the convenience of younger students 
would be consulted by doing so. The author trusts that this selection will 
be found to have been made in such a way that all teachers who possess 
reasonably extensive means of illustrating their lectures, and all Botanic 
Gardens, may furnish the larger part of the species which are mentioned. 
A small selection was indispensable; firstly, because a greater work would 
have been beyond the reach of the majority of purchasers; and secondly, 
because experience shews us that those who have to study a science of 
observation, such as Botany, require to concentrate their attention, in - 
first instance, upon a limited number of objects. 
In the work above referred to, the Vegetable Kingdom is, in the first 
place, divided into Classes; these are subdivided into Sub-classes, which are 
themselves broken up into Alliances ; beneath the Alliances are placed the 
Natural Orders, under which are disposed those final subdivisions termed 
Genera. 
Therefore, genera are groups of species; orders are groups of genera; 
alliances are groups of orders ; sub-classes, when they are employed, are 
groups of alliances, and classes are assemblages of sub-classes (if present), 
or of alliances, or, in some instances, of orders only. Thus we have— 
1. CLASSES. 
2. Sub-classes, 
3. ALLIANCES. 
4. Orvers, 
5, GENERA. 
6. Species. — 
In the following pages the heading of each of these subdivisions is : 
nted i in the type just employed. 
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