Cod livers were given then as cod-liver oil is given now, "to restore them that have melted their Grease." A favorite prescription was "Rulandus, his Balsam which tho' it smel not wel" was properly powerful, and could be gotten down if carefully hidden in "poudered shuger." Cotton Mather, who tried his skilful hand at writing upon almost every grave and weighty subject, composed a book of medical advice called the "Angel of Bethesda." It was written when he was sixty years of age, but was never printed; the manuscript is preserved in the library of the American Antiquarian Society at Worcester. It begins characteristically with a sermon, and is fantastically peppered with pompous scriptural and classical quotations, as was the Mather wont. The ingredients of the prescriptions are vile beyond belief, though, as Mather said in one of his letters, they are "powerful and parable physicks," which are two desirable qualities or attributes of any physic. The book gives an interesting account of Mather's share in that great colonial revolution in medicine--the introduction of the custom of inoculation for the small-pox. His friend, Dr. Zabdiel Boylston, of Boston, was the first physician to inaugurate this great step by inoculating his own son--a child six years old. Deep was the horror and aversion felt by the colonial public toward both the practice and practitioners of this daring innovation, and fiercely and malignantly was it opposed; but its success soon conquered opposition, and also that fell disease, which six times within a hundred years had devastated New England, bringing death, disfigurement, and business misfortunes to the colonists. So universal was the branding produced by this scourge that scarcely an advertisement containing any personal description appears in any colonial print, without containing the words, pock-fretten, pock-marked, pock-pitted, or pock-broken.