On the mechanism of the physiological action of the cathartics

** "On the Mechanism of the Physiological Action of the Cathartics" by John Bruce MacCallum is a scientific work from the early 1900s that studies how saline purgatives work in the body. It investigates and clarifies how these purgatives impact the movement and secretions we find in the intestines. MacCallum summarizes his earlier studies and then goes on to establish a premise for his scientific writing, which consists of summarizing earlier work and introducing new experimental findings measuring the physiological effect of different salts on the intestine. By exploring the effects of different salts, his knowledge of physiology becomes obvious. The initial portion of the document gives an introduction to the life of MacCallum and illustrates how he became an expert in the field of the effects of cathartics. **