Lynn Poole shows William Harvey's 1628 book "Anatomical studies on the motion of the heart and blood", which proved that blood circulates in the body. Mr. Poole then introduces an animated film by Prof. Winifred Cullis, distributed by United World Films, which gives an explanation of the complete heart cycle and blood circulation. It also includes a demonstration of a sphygmograph to record pulse rates before and after exercise. After the film, Dr. Van Slyke discusses the common causes of heart disease and illustrates each using slides.