134 WILD FLOWER PRESERVATION 



ing to the weights. In later changes of driers 

 it will often not be necessary to open the 

 folders at all. 



All damp papers should be dried at once, 

 either in the sun or by a fire; and when dry 

 they should be shaken free from any dust and 

 put away in a drawer for future use. 



Some plants require many changes before 

 they are fit to leave the press, while others 

 are ready for mounting after the third or 

 fourth change. They may be tested by lightly 

 touching with the back of the hand. I once 

 mounted a Parsnip when its umbel was slightly 

 damp. The stem and leaves were perfectly 

 dry, and I thought the clustered flowers might 

 be left to finish off in the herbarium. A fort- 

 night later I had occasion to look at this plant. 

 The Parsnip flowers had changed their yellow 

 for a bright grass-green, and over the whole 

 cluster a fine crop of mildew had grown up ! 



Many botanists now use, in place of one of 

 the driers over each specimen, a sheet of corru- 

 gated board. The effect of this is to ventilate 

 the pile of plants and if the press can be put 

 in a dry place in the sun or in a current of 



