COLLECTION, PRESERVATION, USES, ETC. 31 



as are used by cabinet-makers, and should be at least 

 six inches long, so that several pairs of boards with spe- 

 cimens and rags may be pressed at once. 



Various other modes of applying pressure will readily 

 suggest themselves, such as books, weights, a table- 

 cloth press, or such other means as may be within reach. 

 The thin boards and a good supply of cotton or linen 

 rags, no matter how well worn, to fit them, are all the 

 apparatus absolutely indispensable. Whenever practi- 

 cable, only one layer of specimens should be pressed 

 between each pair of boards. Thus a pile for pressing 

 should be formed in this sequence : — a board, a rag, a 

 series of specimens sufficient to cover the rag without 

 overlapping each other or the edges of the board, another 

 rag, another board, and so on. If the specimens be 

 thick and retain much moisture, a sheet or two of 

 white blotting-paper may be added between the board 

 and the rag, but no coarse or coloured paper that might 

 indent or stain the laying-out paper, or destroy the tex- 

 ture of the specimens, must be used for this purpose. 



In this mode, a day or two will suffice to dry the spe- 

 cimens enough to permit them to be transferred to some 

 old heavy book to be finished off. As a rule, it is de- 

 sirable to change the rags once or twice during the pro- 

 cess of pressing ; but this cannot always be done without 

 disturbing the arrangement of the plant, and when there 

 is any symptom that this will be the case, it is better to 

 let the rags remain until the specimens be dry. If all 

 the specimens between each pair of boards be of nearly 

 uniform thickness, and be placed so that their branches 

 lie in the same direction, they will dry more evenly, and 

 there will be less risk of disturbing them when removing 

 the rags, which should always be stripped off gently, 

 comrnencinsr from the root. 



