"One hundred years ago, juvenile diabetes was a death sentence for millions of people around the world, most of them children. This book tells the story the discovery of insulin, a treatment for this disease and one of the most impactful milestones in medical science. Frederick Banting was a young doctor who was haunted by the memories of the diabetic children he'd treated at Toronto's Hospital for Sick Children. One night, though, he was struck by inspiration--would it be possible to isolate the mysterious secretions of the pancreas (what we now call insulin) and use this substance to treat diabetes? In May 1921, the University of Toronto gave Banting a small lab and a student assistant, Charles Best, to work through Banting's hypothesis. Their test subjects were street dogs--a fact that pained Banting, who had a deep fondness for animals. Banting and Best took exceptional care of the dogs, and Banting ended up giving one the dogs a name -- Marjorie. And when Marjorie--whose pancreas had been replaced by insulin injections--lived 70 days, the experiment was deemed a success. The next step was to try the treatment on a dying child. The effects of insulin on the first human diabetic patient were deemed practically miraculous. However, many dogs did die for this to happen, including Marjorie, whom Banting described as "the most important dog in the world." The back matter includes an Author's Note that provides more information about the disease, as well as about Banting, Best and the insulin dogs. Another section addresses the ethical dilemma of using animals in medical research."--