The stimulation produced by tea and coffee is in some respects like that of alcohol. The heart is stimulated and the blood pressure rises. The kidneys are strongly affected in those unaccustomed to the drug, but this ceases after a week or more of use. Their chief effect is on the brain and nervous system.
Many have boasted that they can take of what they call the good things of life to their full, without any bad effect, and looking over a few years, or even many years, it seems a fact. Some of us have known of such men, who have been esteemed for their joviality and good nature, who have suddenly broken down at what should have been a hearty middle life. On the other hand there are men who were badly equipped for the battle of life, with indifferent constitutions, who never had the buoyancy and overflow of animal spirits, but who with care have long outlived all their formerly more robust but careless companions.
Simple versus Highly-flavoured Foods.—It is very difficult to decide to what extent condiments and flavourings should be used. These have stimulating properties, although differing from the more complex properties of alcohol and the alkaloids. The great differences in the dietetic practices of nations does not appear to be in conformity with any general rule. It varies with opportunity, climate and national temperament; though doubtless the national temperament is often due in part to the dietetic habits. Some races are content with the simplest foods, large numbers subsist chiefly on rice, others on the richer cereals, wheat, oatmeal, etc., and fruit. On the other hand there are races who enjoy stronger flavoured food, including such things as garlic, curry, pickles, pepper, strong cheese, meat extracts, rancid fats, dried and smoked fish, high game or still more decomposed flesh, offal and various disgusting things. The Greenlanders will eat with the keenest appetite, the half-frozen, half-putrid head and fins of the seal, after it has been preserved under the grass of summer.