America would not have developed the atomic bomb or radar if the current government recreations on visas for foreign students had been in effect in 1942, the Dean of the Division of Applied Science School told a meeting of the American Physical Society yesterday afternoon in Sanders Theatre.

Dean John H. Van Vleck, who is also retiring president of the Society, surprised the assembled scientists, who were led by his title. "Two Barrier Phenomena."-to believe that the talk would be scientific.

Citing resolutions adopted by the Council of the Society. Van Vieck said that such policies have seriously hindered the international spread of ideas. Scientific meetings scheduled for the United States have been forced to assemble abroad, because so many of their members could not gain entrance to this country.

Security Unaided

These policies have not contributed a single bit to the strengthening of American security, he said, for all the meetings were to be open.

"We spend millions of Marshall Plan aid, and then delivery the benefits by a woodenly administered immigration police." he said.

"Classified information in the hands of an enemy is obviously a danger." he continued. "but I cannot see the Danger of letting casual visitors into the country."

"The moment we start guarding our tooth bushes with the same real with which we guard on wings. We will have certainly lose less toothbrushes, but almost as certainly more diamonds."

The second barrier discussed by Van Vleck was of a scientific nature. The inversion Spectrum of Ammonia."

Van Vleck's address was followed by the presentation of the Oersted Medal of the American Association of Physics Teachers to R. M. Sulton. Chairman of the Physics department at Hartford College the award annually goes to a leading teacher of physics.

After the presentation. Edward M. Purcell professor of Physics delivered the Richtmyer Memorial Lecture, speaking on under magnetism, the field for which he won this year's Nobel Prize

Final sessions of the Society's Convention will be held today.