Gross and microscopic studies of the auriculoventricular conduction system were performed in 60 human hearts. A unique technic is introduced which will produce a photographic. record of undistorted serial sections through a block containing the auriculoventricular node, auriculoventricular bundle and branches. By projecting the completed film as a motion picture, the course and changing relatio...

IN this outstanding 2"x2" Slide Projector, Bausch & Lomb has utilized the experience gained in manufacturing motion picture optical systems to give the user screen images of professional quality from black and white or color slides. Despite the exceptional brilliance of the screen images, slide temperature is kept within safe limits for all normal projection. The Bausch & Lomb 2"x2" Slide Proje...