Radio age research, manufacturing, communications, broadcasting, television (1941)

MICROSCOPE AIDS DENTISTRY RCA Electron Instrument Reoeals Details of Teeth Never Seen Before Society Elects Hillier President. Banco Secretary-Treasurer. tj^ LECTRON microscopes devel- u oped by the Radio Corporation of America and now used exten- sively in the war effort have opened man\' new possibilities for civilian application after military pressure diminishes, according to papers presented at the November meeting of the Electron Microscope Society of America in Chicago. Attending the three-day conference were elec- t r o n microscopists representing more than a score of leading college and industrial laboratories. Dr. James Hillier, of RCA Laboratories, Princeton, N. J. was elected Presi- dent, and M. C. Banca, of the RCA Victor Division, was re-elected Sec- retary-Treasurer of the Society. It was disclosed that the electron microscope, by means of which ;i tooth area one-tenth the width of a toothbrush bristle can be photo- graphed and studied, holds far- reaching prospects for dentistry. Dr. C. H. Gerould. research engi- neer with the Dow Chemical Com- pany, Midland. Mich., explained it this wax': "It is as tlmugli the dark- ened lal)oratories of denial techni- cians suddenly were Hooded with light. With the electron microscope, tooth structures whose very exist- ence had been iTi doubt can be seen, measured and examined." One of the examples cited 1)\ iJr. Gerould were tiny canals within teeth. Micrographs obtained with an RCA electron microscope, he said, revealed each human tooth to contain 50,000 miles of these canals, which no eye had ever seen. He showed pictures of a cross-section area of a tooth, magnified 5,300 times, in which the openings ap- peared as huge craters. The increased knowledge of tooth structures and the greater oppor- tunity for earlier detection of dis- eases of the teeth which the elec- tron microscope has made possible should, in Dr. Gerould's opinion, help dental researchers in the fur- ther development of methods of tooth ju-esei-vation. "Preliminary work on tooth structures," he said, "has indicated that the electron microscope can be used successfully towards giving the dental research worker a new- tool for api)lication in his field." The micrographs, shown by Dr. Gerould at the meeting, were all stereoscojiic views, showing three dimensions. So exact is the opera- tion, it was explained, that a mag- nified image can be adjusted to within one-sixteenth of an inch at 20,000 diameters. This corresponds to the actual movement of the speci- men to an accuracy of three one- millionths of an inch. A square area RCA ELECTRON MICROSCOPES, LIKE THIS COMPACT DESK MODEL, ARE EXPECTED TO OPEN MANY NEW POSSIBUJTIES FOR CIVILIAN APPLICATION EARLY IN THE POSTWAR YEARS. ■J 1000 of an inch on the side, when magnified 20,000 times, becomes 40 inches on a side. To complete a mosaic it would require 400 regular 2" X 2" micrographs and were these enlarged to 100,000 times, it would re(|uire i)hotographic paper sufli- cient to cover an area one-ipiarter of an acre in size. Perry C. Smith, Manager of the Electron Microscope Section of RCA, reported that thousands of micrographs had been made since August, 1941, when a sjiecial group was organized at the RCA Victor Division to handle advanced work, production and design of RCA's electron microscopes. He and his assistant. Dr. Robert G. Picard, de- scribed in a paper the two latest RCA electron microscopes. The models represented four years of intensive research and engineering by Dr. V. K. Zworykin, Associate Research Director of RCA Labora- tories, Dr. Hillier and Mr. Smith. One of the instruments is a stream- lined version of the electron micro- scope now being utilized in wartime research by large medical, indus- trial and university laboratories. The other is a console model for the nation's disease fighters, food proc- essors and industrial research men working in smaller laboratories. A revelation which attracted wide interest at the conference dealt with our future wearing apparel. Post- war pants may not bag at the knees so quickly or post-war shirts clutch so tightly at the neck: woolen sweaters may come out of the washer the same size as when they went in. These prospects came from studies made with the RCA electron microscope by D. H. Reynolds and J. A. Rich of the Monsanto Chem- ical Co., Dayton, Ohio. These experts explained that the microscope permitted such detailed examination of the fibers of clothing materials that the effect on these materials of water and other sub- stances could be accurately deter- mined. It was found that treating the fibers with certain types of [RADIO AGE 16]