Potassium salts are as essential to the nutrition of the body as salts of sodium, and are probably in great measure able to replace them, but our knowledge on this point is not in a very advanced state. Bunge, who is at present engaged in research on the subject, gives a table of the proportion of sodium to potassium in certain foods.

To one equivalent of sodium there is -

In yolk of egg........

1 equivalent of potassium

,, milk.........

0.8 to 6 equivalents ,,

,, veal.............

4 „ ,,

,, wheat..........

12 ,, 23 „ ,,

,, potatoes..........

31 „ 42 „ ,,

,, peas...........

44 „ 50 „ ,,

There is a fairly prevalent belief that it is unwise to include too much potash in our diet because of its depressant effect. Whatever truth there may be in this belief, it must surely be confined to its employment as a drug, and we know that in large doses potassium salts are pure protoplasmic poisons, specially acting upon the more highly organised nerve centres and the heart muscle. But there is no evidence that such foods as beans, peas, lentils, and potatoes in moderation act in a deleterious capacity because of their potash content.