James studied at Oxford and was granted his M.D. from Cambridge by royal mandate in 1728. He settled in London after practicing at Sheffield, Lichfield, and Birmingham. A successful physician, he became quite wealthy and famous when his “fever powder” became the most popular nostrum of the day. The chief ingredients were lime phosphate and antimony oxide and the medicine was used as an emetic, purgative, diaphoretic, or alterative depending on the dose and condition of the patient. James authored a number of books but the present work is the one for which he is best remembered.
It remains the largest, most exhaustive, and most erudite English language medical dictionary written before the nineteenth century. It was published in weekly installments beginning in 1742 and ending in August of 1745. Although never identified or acknowledged by name, there is ample evidence that Samuel Johnson, a close friend and student of James, contributed to the dictionary.
It is interesting that James includes a detailed entry on the unicorn horn (shown here) at a time when most scientists had begun to doubt its existence.