But among the new things which the people were to try in that century was one which led to most beneficient results. For many generations the great scourge of Europe was the smallpox. Often the disease was as violent as the plague (S474), and carried off nearly as many victims. Medical art, seemed powerless to deal with it, and even in years of ordinary health in England about one person out of ten died of this loathsome pestilence. In the early part of George I's reign, Lady Mary Montagu, then traveling to Turkey, wrote that the Turks were in the habit of inoculating their children for the disease, which rendered it much milder and less fatal, and that she was about to try the experiment on her own son. Later, Lady Montagu returned to England, and through her influence and example the practice was introduced there, 1721. It was tried first on five criminals in Newgate who had been sentenced to the gallows, but were promised their freedom if they would consent to the operation. As it proved a complete success, the Princess of Wales, with the King's consent, caused it to be tried on her daughter, with equally good results. The medical profession, however, generally refused to sanction the practice, and the clergy in many cases preached against it as an "invention of Satan, intended to counteract the purposes of an all-wise Providence." But through the perseverance and good sense of Lady Montagu, with a few others, the new practice gradually gained ground. Subsequently Dr. Jenner began to make experiments of a different kind, which led, late in the century (1796-1798), to the discovery of vaccination, by which millions of lives have been saved; this, and the discovery of the use of ether in our own time (S615), may justly be called two of the greatest triumphs of the art of medicine. 538. How Sir Robert Walpole governed. We have seen that Sir Robert Walpole (S534) became the first Prime Minister in 1721, and that he continued in office as head of the Cabinet, or Government, until near the middle of the next reign. He was an able financier, and succeeded in reducing the National Debt (S503). He believed in keeping the country out of war, and also, as we have seen, out of "bubble speculation" (S536). Finally, he was determined at all cost to maintain the Whig party in power, and the Protestant Hanoverian sovereigns on the throne (SS515, 532).