present in a man's body; so. is phosphorus in his bones, blood and brain : hydrogen is in all the fluids, and in some of tbe solids ; carbon is In all the secretions nnd excretions : iron is an essentia] of the blood; soda is in his muscles: silex is found in the hair and nails; magnesia exists in blood and brain ; lime is abundant in the liones; albumen and fibrin, and sulphur