18 



HORTUS SiCCUS. After having collected as good a specimen as 

 possible of the plant, lay it flat, disposing of it in the best man- 

 ner, betwixt sheets of white paper, so that the flowers and leaves 

 do not interfere with each other : put this on a quire of blotting 

 paper, and also a quire over it, and then apply a weight on the 

 top books answer this purpose very well. The next day put dry 

 blotting paper as before, first opening the sheet of paper, and 

 making any alterations in the disposition of parts. Dried speci- 

 mens are to be fixed into slips of paper or glued with common 

 glue. These should be kept in shelves or drawers. To prevent 

 the depredation of insects, Dr. Smith recommends a solution of 

 corrosive sublimate (muriate of mercury,) in some spirits of wine, 

 with which the plants are, when dry, to be gently moistened. 



IMPERFECT PLANTS. Apparently defective in one or other of 

 the more conspicuous parts or organs, whether conservative 

 or reproductive, are denominated imperfect, and are called 

 Cryptogamous, because their organs of fructification are not yet 

 detected, or are so minute as to require the aid of a microscope 

 to render 'them visible, as in the Filices, Musci, Hepaticee, Algae, 

 Lichens, and Fungi. 



IMPROVEMENT OP SOILS. Soils may be rendered more fit for 

 answering the purposes of vegetation by pulverization, by con- 

 solidation, by exposure to the atmosphere, by an alteration of 

 their constituent parts, by changing their condition with respect 

 to water, by changing their position with respect to atmospheri- 

 cal influence, and by a change of the kind of plants cultivated. 

 AH these improvements are independently of the application of 

 manure. The fibres of roots take up the extract of the soil by 

 intro-susception : the quantity taken up therefore will not depend 

 alone on the quantity in the soil, but on the number of the 

 absorbing fibres. The more the soil is pulverized, the more these 

 fibres are increased : and the more extract is absorbed, the more 

 vigorous does the plant become. Pulverization, therefore, is not 

 only advantageous, previous to planting or sowing, but also during 

 the progress of vegetation, when applied in the intervals between 

 the plants. In this last case it operates also in the way of 

 pruning, and by the cutting off the extending fibres, causes them 



