Simplified Cross Section Slicer.-DR. J. I. HARDY, senior fiber technologist of the Bureau of Animal Industry, has invented a small mechanical device which makes possible the rapid cross sectioning and clear study of the structure of hair, wool, mohair, fur, silk, cotton and other fibers, both natural and artificial.
The new discovery enables the preparation of very thin cross sections ready for examination within ten minutes, whereas in the past it required several hours to obtain them.
Sections, one-ten thousandth of an inch, can be cut without injury to the delicate internal structure.
Moreover, such thin cross sections, even of seemingly opaque fibers, are sufficiently transparent for microscopic study.
Dr. Hardy has applied for a public patent on his device, which is about 3 inches in length and consists of three metal parts.
A thin piece of metal contains a slot 0.0085 of an inch wide. A second thin flat piece of metal slides parallel to the first and pushes a short metal guide down the slot, pressing the fibers tightly together in a vertical position.
The third part contains a small metal plunger on the end of a supporting screw for pushing the fibers ever so slightly through the slot.
After the fibers are inserted and firmly secured in the slot, they are cut off on both sides of the holder with a safety razor blade.
The plunger is then used to push the fibers from one side to the other according to the thickness of the cross section desired.
A drop of celluloid is put on the projecting ends and this dries quickly without soaking into the fibers.
The celluloid and fiber ends are cut off by the blade and the thin celluloid slice carrying the tiny disks of fibers is ready to be mounted on the microscope slide.
Many practical applications are forecast for this device.
Information on the types of hair and fibers in various furs, fabrics, and industrial products can be supplied quickly and accurately. The invention should be valuable in livestock breeding by aiding stockmen in the development of animals with hair, wool, mohair, etc., of a kind in greatest demand in industry.
It is particularly believed the new instrument will have far-reaching possibilities in the detection of crime.
Cross sections of fiber clues may be studied directly through a microscope or by making microphotographs which may be filed away for further reference or sent to any part of the world for comparative study.
C.