Springfield, Mass., June 16, 1906.
To the Editor:
—At the Boston session of the American Medical Association one of the things that struck me very forcibly was the number of good exhibits of x-ray apparatus made almost useless through inferior tubes. Apparatus that per se seemed powerful enough, developed no clear-cut image on the screen. In many instances complicated foreign tubes were being exploited. These were expensive and seemed to me only remarkable for the amount of inverse discharge they recorded. I have for some time been using Green and Bauer American-made tubes and find them much better than the imported Gundelach tubes I formerly employed. Why go past a good American product for an inferior foreign make? I agree very heartily with Dr. Piffard in his paper concerning the value of tubes that these (tube No. 2 being G. & B.) are remarkable not only as to lack