The science of medicine has for thousands of years to some extent depended upon finding out the complaints of the body by its rhythm and by the breath. Ancient medicine knew that health depends upon vibrations, and now again a time is coming when in the Western world physicians are striving to find out the law of vibrations upon which man's health depends. But man, absorbed in the material life, goes so far and no further. The mystery of vibrations does not concern the material plane only: it goes still farther.