Book is a classic frequently referred to in many other books on energy medicine. Burr was a professor at Yale who did experiments in the 1970s and was able to detect electrical fields around plants and animals, which he called the "l-field" or "life field." This book appears to be a summary of his findings and their implications, written for the lay person, followed by the technical results of his experiments for those who may wish to read his methodology for himself and possibly repeat it.