ELECTRON BEAM

Wairarapa Times-Age, 24 March 1942, Page 4

ELECTRON BEAM

TOOL FOR SCIENTISTS NEW MICROSCOPIC WORLD. SENSATIONAL DISCOVERIES. An ordinary microscope with glass lenses has limitations imposed by light, Light is a wave motion in the ether, if you still believe in that hypothetical medium. The waves measure a thousandth of a millimetre from crest to crest. Anything smaller than a wave length is simply drowned in light. Just as a rowboat is lost to view in the trough Of two big waves, sO a submicroscopic particle is lost to view in light. : The best microscope cannot magnify more than about 2500 diameters. Something much finer than light is needed to magnify ten, fifty, a hundred thousand times. The electron beam is something finer. What all this means may, be gathered from the fact that if a human hair were magnified 45,000. times it would have an apparent diameter of ten feet.

The electrons get sufficient speed to penetrate the object to be studied. That object is only one one-hundred-thou-sandth of an inch thick. The “lenses’’ are niagnetic coils which focus the electron rays. The image is either observed directly on a fluorescent screen or. photographed. Magnifications of 100,000 diameters are possible. DISEASES SOON ATTACKED. New facts are being gathered with the aid of the electron microscope, but as yet scientists find it hard to interpret them. As might be expected, the diseases ' were soon attacked. It was found that the streptococcus hemolyticus, a micro-organism which dissolves blood corpuscles, is literally encased in stout armour. Outer protective shells have also been found in pneumococci and typhoid bacilli, which helps to explain why they are so difficult to kill. The virus of the tobacco mosaic disease, invisible in the ordiriary microscope, turns out to contain rod-shaped bodies. The viruses of the diseases known as “tomato bushy stunt” and “tobacco necrosis” are spherical. It is now possible to study in detail how these virus bodies congregate, as well as the action of chemicals and antibodies on them. Dr. Frances Seymour has used the electron microscope to reveal curious bulges and hairs on human spermatozoa. CHALK STRUCTURES SHOWN. Electron micrographs show that precipitated chalk, jnagnified 36,000 times, is made up of tiny elongated prisms massed together to form groups with very porous internal structures and rough surfaces. Two type's of bacteria (Eberthella typhosa and coliform bacteria) are equipped with long, tubelike arms, called flagella, which act as propellers. Soap is composed of twisted fibres. When the electron microscope is turned on a mosquito, “breathing tubes” branching out to all parts of the organism stand out. Tire tubes are veritable “windpipes.” There are spiral thickenings or tiny hoops that line and reinforce the wall. The hoops are only one fifty-thousandth of an inch wide, which explains why they have not hitherto been seen. Within the tubes are spines only a quarter of . a millionth of an inch in length. It looks very much as if the s'ehsational discoveries made by Pasteur and Koch in their day will be matched by electron microscopists.