105     Latterly it has been the habit to entrust the proving of medicines to unknown persons at a distance, who were paid for their work, and the formation so obtained was printed. But by so doing, the work which is of all others the most important, which is to form the basis of the only true healing art, and which demands the greatest moral certainty and trustworthiness, seems to me, I regret to say, to become doubtful and uncertain in its results and to lose all value.