THE USE AND ABUSE OF FOOD. 341 



But we have to consider the other mineral constituents of 

 the system. 



If I were to run through the list of all the minerals which 

 exist within the body, I should weary the patience of the 

 reader, and perhaps not add very much to the clearness of 

 his ideas respecting the constitution of the human frame. 

 Let it suffice to state generally that, according to the calcu- 

 lations of physiologists, a human body weighing 154 pounds 

 contains about 17^ pounds of mineral matter; and that the 

 most important mineral compounds existing within the body 

 are those which contain lime, soda, and potash. Without 

 pretending to any strictly scientific accuracy in the classifica- 

 tion, we may say that the lime is principally found in the 

 bones, the soda in the blood, the potash in the muscles ; and 

 according as one or other of these important constituents is 

 wanting in our food, so will the corresponding portions of the 

 frame be found to suffer. 



We have a familiar illustration of the effects of unduly 

 diminishing the supply of the mineral constituents of the 

 body in the ravages which scurvy has worked amongst the 

 crews of ships which have remained for a long period ill- 

 supplied with fresh vegetables. Here it is chiefly the want 

 of potash in the food which causes the mischief. An interest- 

 ing instance of the rapid almost startling effects of food 

 containing potash, in the cure of men stricken by scurvy, 

 is related by Dana. The crew of a ship which had been 

 several months at sea, but was now nearing the land, were 

 prostrated by the ravages of scurvy. Nearly all seemed hope- 

 lessly ill. One young lad was apparently dying, the livid 

 spots which were spreading over his limbs seeming to betoken 

 his rapidly approaching end. At this moment a ship ap- 

 peared in view which had but lately left the land, and was 

 laden with fresh vegetables. Before long large quantities of 

 the life-bearing food had been transferred to the decks of the 

 other ship. The instincts of life taught the poor scurvy- 

 stricken wretches to choose the vegetable which of all others 

 was best suited to supply the want under which their frames 



