a town of the Netherlands, in the province of Liege and arrondissement of Verviers. It is one of the oldest, and was the most frequented, of the continental watering places. Its name has become generic for similar springs. It is situated in a narrow valley watered by a rapid and clear brook. The town consists of detached houses of all sizes, appropriate to the circumstances of the several classes of visitors.

The most remarkable waters are, 1. The Pouhon, situated in the middle of the town, which is more strongly impregnated with steel than the others; 2. The Sauveniere, a mile and a half east from it; 3. Grosbeck, near to the Sauveniere; 4. Tonnelot, situated a little to the left of the road which leads to the Sauveniere; 5. Geronstere, two miles south from Spa; 6. Wartroze, near to the Tonnelot; 7. Sarts or Niveset, in the district of Sarts; 8. Chevran or Bru, in the principality of Slavelot; 9. Couve; 10. Beverse; 11. Sige; 12. Geremont. These four last are near Malmedy.

Dr Brownriggs was the first person who discovered that carbonic acid gas forms a principal ingredient in the composition of the Spa waters, and actually separated a quantity of this elastic fluid, by exposing it to different degrees of heat from 110° to 170° of Fahrenheit. From twenty ounces seven drams and fourteen grains apothecaries' weight of the Pouhon water, he obtained eight ounces two drams and fifty grains.

The Spa waters are diuretic, and sometimes purgative. They exhilarate the spirits; and are more cooling, and allay thirst more effectually, than common water. They are found beneficial in cases of weakness and relaxation, either partial or universal; in nervous disorders; in obstructions of the liver and spleen; in cases where the blood is too thin and putrescent; in cases of excessive discharges proceeding from weakness; in the gravel and stone; and in most cases where a strengthening remedy is wanted. But they are hurtful in confirmed obstructions attended with fever, where there is no free outlet to the matter, as in ulcerations of the lungs. They are also injurious to bilious and plethoric constitutions, when used before the body is cooled by proper evacuations.

Spa was more fashionable formerly than it is at present. There are in it manufactures of iron, wood, and gilt toys. The resident inhabitants are about 3300.