INTEODTJCTION. 



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If the specimen is very busliy, some branches must be thinned out, but 

 always so as to show where tlie brancli has been. 



If any part, such as tlie head of a thistle, the stem of a broomrape, or 

 the bulb of a lily, be very thick, a portion of what is to be the under side of 

 the specimen, may be shced oiF. Some thick specimens may be split from 

 top to bottom before drying. 



If the specimen be succulent or tenacious of life, such as a sedum or an 

 orchis, it may be dipped in boiling water, all but the flowers. This will kUl 

 the plant at once, and enable it to be dried rapidly, losing less of its colour 

 or foliage than would otherwise be the case. Dipping in boiling water is 

 also useful in the case of heaths and other plants which are apt to shed their 

 leaves during the process of drying. 



The number of sheets of paper to be placed between each specimen, or 

 Bheet of specimens, will depend on the one hand on the thickness and hu- 

 midity of the specimens, on the other hand, on the quantity and quality of 

 the paper one has at command. The more and the better the paper is, the 

 less frequently will it be necessary to change it, and the sooner the plants 

 will dry. The best paper now made m England is Bentall's. On the Con- 

 tinent the common unsized grey paper is to be had very much cheaper. 



Care must be taken that the paper used is well dried. It it be likewise 

 hot, all the better; but it must then be very dry; and wet plants put into 

 hot paper will require changing very soon, to prevent their turning black, 

 for hot damp, without ventilation, produces rapid fermentation. 



For pressing plants, various more or less complicated and costly pi-esses 

 are made. Kone is better than a paii" of boards the size of the paper, and 

 a stone or heavy books or other weight upon them if at home, or a pair of 

 strong leather straps round them if travelling. Each of these boards shoidd 

 be double, that is, made of two layers of thin boards, tlie opposite way of 

 the grain, and joined together by a row of clenched brads round the edge, 

 without glue. Such boards, in deal rather less than half an inch thick (each, 

 layer about 2^ Hues), will be found Uglit and durable. 



It is useful also to have extra boards or pasteboards the size of the paper, 

 to separate thick plants from thin ones, wet ones ft-om those nearly dry, etc. 

 If some of these intermediate boards be made of two layers of narrow strips, 

 crossing each other at right angles, with inteiTals between the strips of each 

 layer, the ventilation produced will much accelerate the drying, without 

 frequent changing. Such an apparatus as described and figured in the 

 ' Gardeners' Chronicle,' 1852, p. 164, admirable for home use, is, however, 

 rather bulky for travelling. 



The more frequently the plants are changed into dry paper the better. 

 Excepting for very still' or woody plants, the fu-st pressure should be light,. 

 and the first changing, if possible, after a few hours. Then, or at the second 

 changing, when the specimens wUl have lost their elasticity, but wiU not 

 yet have dried stiif, will be the time for putting right any part of the speci- 

 men which may have taken a wrong fold or a bad direction. After this the 

 pressure may be gradually mcreased, and the plants left from one to several 

 days without changing. The exact amount of pressure cannot be given, as 

 it will depend on the consistence of the specimens and the amount of paper.' 

 It must only be borne in mind that too much pressure crushes the delicate 

 parts, too little allows them to shrivel, in both cases interfering with their 

 future examination. 



The most convenient specimens wdl always be made, if the drying paper 

 ia the same size as that of the herbariiun in which they are to be keptv 



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