Part 1 



Preservation of Natural Color in Plant 

 Specimens Mounted in Plastic Plates 



The process (25) 1 described in part 1, which includes fixing of natural 

 :olors 2 and mounting; of pressed specimens in plastic plates, is adapted 

 specially to plant foliage , sections , and flowers , preserved specimens of 

 vhich are shown in plate 1 . 



EQUIPMENT AND SUPPLIES 



The essential items of equipment and the principal supplies needed 

 or the preparation of specimens by this method are listed below. The 

 quantities indicated are based on the initial needs of one or two workers 

 ind should be Increased proportionately when additional persons are 

 ;o undertake the work. Electrical equipment, including lights and 

 switches, used in rooms where flammable substances or their vapors 

 nay accumulate should be of the type approved under Article 500 of 

 he National Eiectric Code. 



Equipment 



[Ite.ms followed by an asterisk (*) are not essential, but will be found 

 helpful, especially when the work is done on an extensive scale.] 



Description Number 



electric refrigerator (large or medium size) 1. 



Electric hot pla?e (adjustable temperature) * 1. 



I Heated mounting table, comprising an electrically heated water bath, or 



equivalent, covered with a smooth metal or glass plate, approximately 



18 inches by 7-2 inches (thermostatic control not necessary) 1. 



Electrically netted squeegee (small photoprint sealer or equivalent ) 1 . 



' Thermometer, ^50° C 1. 



Laboratory balance, 0.1 gm. to 1,500 gm.* _- 1. 



Hydrogen-ion ( omparator, pH range approximately 2.5 to 9.0* 1 . 



Rectangular glass or enamel ware dishes with covers, 3 inches by 7 inches 



by 3 inches, or larger 15. 



Glass (or plastic) grids or strips to serve as hold-downs in the rectangular 



dishes 15. 



Glass funnels (or thistle tubes) approximately 1 l A inches in diameter 20. 



Glass jars , 4-oi»nce . with mouths approximately 1 % inches in diameter. _ 20. 



Glass jars, 12-ounce or 16-ounce 25. 



Clip-board, approximately 10 inches by 16 inches, provided with a 



hinged arm, for use as a layout frame* •> 1 . 



Plant press, strap type, with double faced corrugated paperboard 



ventilating spacers 2. 



Trays (plastic, metal, or wood), approximately 12 inches b}~ 18 inches by 



% inch 20 or more. 



1 Italic numbers in parentheses refer to Literature Cited, p. 71. 



2 The basic process for preserving the natural color in plant specimens as described 

 herein is covered by a patent issued to Fessenden (.25) which stipulates that the United 

 States Government may use the process royalty-free for Government purposes. While 

 all rights under the patent, other than those granted to the United States Government, 

 are retained by the patentee, he has given his consent to the use of the patented process, 

 as well as the modifications described herein, for educational and other nonprofit 

 purposes. 



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