"PEELED" COAL OPENS FIELD FOR MICROSCOPE

Through the use of a new microscope technique, scientists may now study fossilized plants under a tremendous magnification. Under the new method it is possible to magnify a cross-section less than one twenty-five thousandth of an inch thick to 500 diameters.

Cell Construction

Previously, the cross-sections taken were much thicker and darker and could not be magnified beyond 60 diameters. The new process, perfected by William Darrah, instructor in Botany, reveals the cellular construction of fossils with heretofore unequalled clearness.

New Field Open

One of the most important fields opened up by the new technique is the detailed study of the plant life involved in the formation of anthracite coal and petrified woods. Never before have botanists been able to secure satisfactory microscopic specimens from these hard rocks. Mr. Darrah has succeeded in making fossil peals of both coal and petrified woods, among them specimens containing the remains of pollen grains more than 200,000,000 years old from a coal deposit in Illinois.

The Process

The process is a simple one. First the fossil area in the rock is polished with an abrasive wheel. The area is then treated with acid, and coated with a special nitro-cellulose solution. When this has dried, forming a tough film, it is 'peeled' off and retains a carbonized impression of every detail. It is estimated that 500 specimens can be made from a fossil an inch thick. The specimens can be made very cheaply and are indestructible under ordinary handling.