OCR Text |
Show Preserve Plants and Insects in Their Natural Colors Two methods of preserving indefinitely indef-initely in their natural colors such agricultural specimens as leaves, flowers, fruits, seeds, insects, and other biological material have been developed by chemists of the United States department of agriculture. The processes, while supplementing each other, have different fields of application one for dried and the other for fresh material. In the method studied by Dr. Charles E. Sando, specimens are suspended and embedded in metha-crylate, metha-crylate, a crystal-clear plastic similar sim-ilar to materials used in making nonshatterable airplane windows. In this process, the specimens must be dehydrated or dried out to prevent pre-vent moisture from clouding the glass-like plastic material. They may be air-dried or dehydrated by-use by-use of alcohol or ether. Corn and other grains or seeds, insects, or anything that does not lose its color or shape with drying, may be preserved by this nt-thod, possibly only under controlled laboratory lab-oratory conditions. Once the plastic plas-tic sets it can be machined and polished pol-ished to a high luster so that the specimen may be viewed from any angle without distortion. The larg est mount prepared so far is an ear of hybrid corn. The other method, developed by G. R. Fessenden, is a chemical process for treating fresh plant material ma-terial in such a way as to toughen the tissues and set the natural color. col-or. The natural beauty of flowers, or the exact appearance of either healthy or diseased leaves, can be preserved by immersion in specially special-ly formulated water - removing syrups. Each plant species requires an individual treatment which has to be worked out from seven general gen-eral types of formulas. The old method of preserving botanical specimens pressing and drying was unsatisfactory because of loss of color and the fact they were easily destroyed by handling or by insects or mold. Specimens preserved by this new method are scaled between sheets of cellulose film so as to be protected from damage. Due to the expected permanence of specimens preserved by either method, excellent records of both healthy and abnormal plants and ir-sects ir-sects may be made available for scientific research, study, and exhibition. |