"It is true, says Liebeg, that thousands have lived without a knowledge of tea and coffee; and daily experience teaches us that, under certain circumstances, they may be dispensed with without disadvantage to the merely animal functions, but it is an error, certainly, to conclude from this that they may be altogether dispensed with in reference to their effects; and It is a question whether, if we had no tea and no coffee, the popular instinct would not seek for and discover the means of replacing them."