The old Dutch law condemned criminals to a diet of unsalted food, the effects being said to be those of the severest physical torture.

Years ago an experiment tried near Paris demonstrated the necessity of its use.

A number of cattle were fed without the ration of salt; an equal number received it regularly.

At the end of a specified time, the unsalted animals were found rough of coat, the hair falling off in spots, the eyes wild, and the flesh hardly half the amount of those naturally fed.
A class of extreme Grahamites in this country decry the use of salt, as well as of any form of animal food; and I may add that the expression of their thought in both written and spoken speech is as savorless as their diet.
Salt exists, as we have already found, in the blood: the craving for it is a universal instinct, even buffaloes making long journeys across the plains to the salt-licks; and its use not only gives character to insipid food, but increases the flow of the gastric juice.
Black pepper, if used profusely as is often done in American cooking, becomes an irritant, and produces indigestion.

Red pepper, or cayenne, on the contrary, is a useful stimulant at times; but, as with mustard, any over-use irritates the lining of the stomach.
So with spices and sweet herbs.