IJ2 THE PLANT WORLD. 



when the plants are thus mounted they are mounted to stay, and can 

 never be taken from the sheets and their undersides examined. If 

 we had to deal with specimens made in the old way, with every leaf 

 and flower carefully pressed with the same side up, this objection 

 would have some weight, but as plants are now pressed there are 

 always leaves enough showing the undersides, and flowers enough to 

 show all parts, making it unnecessary to remove plants from the 

 sheets. 



The first attempts at gluing plants were made with glue such as 

 cabinet-makers use. It was applied hot with a brush, and besides 

 being a tedious method, frequently wrinkled or discolored the mount- 

 ing paper. The kind now used is the prepared liquid glue, which is 

 quite satisfactory. It may be bought at any hardware store. In 

 mounting plants by the new method, all that one needs besides the 

 glue is a stock of driers, some collecting sheets and a sponge. After 

 the label has been pasted upon the sheet to be used in mounting, the 

 operation proceeds as follows: Having spread a little of the glue very 

 thinly on a piece of paste-board or old newspaper, two driers are laid 

 upon the table and on them the mounting sheet. The plant is laid 

 down in the glue and at once taken up and transferred to the mount- 

 ing sheet. It is then covered with a sheet of thin white paper, such 

 as a collecting sheet, two more driers are put upon it and it is finished. 

 The operation is repeated with other plants, which are piled up one 

 above another with driers between as in pressing plants. When about 

 six plants have been treated thus, the pile is put under about twenty 

 pounds pressure while another half-dozen are being mounted. After 

 this the thin sheets covering the first mounted specitnens are turned 

 over, to prevent any glue which may have got on the upper surface of 

 the plant from sticking them together. The pile may then be set 

 away under pressure for a day or two for the glue to dry. 



A few minutes' practice will enable any one to satisfactorily mount 

 plants in this manner. Two hundred plants in seven hours is a fair 

 average. If the glue is too thick, it may be thinned with a little 

 vinegar. It is not intended that every part of the under surface shall 

 be covered with glue. On the contrary, if a plant is laid loosely on 

 the sheet, it will be seen that it touches it at comparatively few points. 

 If these are covered with glue, it will be sufficient. Heavy stems 

 should, of course, have the greatest amount of glue. If the plant 

 takes up too much glue when dipped into it, the excess may be taken 

 off by laying the plant with glued side down on a piece of newspaper. 

 Repeat this until enough has been removed. The sponge is kept wet, 

 near at hand, for taking glue from the operator's fingers and from the 

 upper surface of the plants, 



