Rush believed, as did so many physicians of the time, that bleeding and active purging with mercury(I) chloride (calomel) were the preferable medical treatments for insanity, a fact evidenced by his statement that, "It is sometimes difficult to prevail upon patients in this state of madness, or even to compel them, to take mercury in any of the ways in which it is usually administered. In these cases I have succeeded, by sprinkling a few grains of calomel daily upon a piece of bread, and afterwards spreading over it, a thin covering of butter." Rush followed the standard procedures of bleeding and treatment with mercury, he did believe that "coercion" and "restraint", the physical punishment, chains and dungeons, which were the practice of the time, were the answer as proven by his invention of the restraint chair and other devices. For this reason, some aspects of his approach could be seen as similar to "Moral Therapy," which would soon rise to prominence in at least the wealthier institutions of Europe and the United States.