A level look at the sea inside us, the more than 60% fluid content (and its contents) of the human body and its effects on health and behavior. During a cholera plague early in the 19th century a Dr. Latta discovered the virtue of injecting fluid--a finding ignored for many years later. Dr. Snively here discusses the current knowns about fluid retention and regulation (kidneys, glands, lungs); about salt or sodium which can be intoxicating (if too little) or toxic (if too much); potassium; calcium; phosphorus; magnesium the ""starter fluid""; the various nutrients, vitamins and microminerals. Then there are the inner tides and rhythms which account for say shock and seemingly have a bearing on emotional illness. Throughout there are remedial revelations: milk is not the complete food. And although the subject might sound limiting, many aspects of health and ill health are involved. For the popular science-minded and not over the head of anyone.