Acupuncture has been practiced in China for more than 2 000 years, but its using Western world is still very new. Several hospitals in the United States are now experimenting with acupuncture as a way of treating pain. An American journalist who stood beside a patient during an operation in Shanghai recently described the process and its effects. To keep the patient from feeling pain during the operation, four needles were used, each about an inch and a half long. Two needles were inserted under the skin on each side of the patients neck. The tops of the needles were attached to wires which led to a small electrical device. Throughout the operation the patient talked calmly to those standing around him, insisting that he felt perfectly normal. How docs acupuncture work? How is it able to keep a patient from feeling pain? No very satisfactory answer has been given, hut there are at least three theories. Some doctors believe that acupuncture somehow produces an effect upon the central nervous system. Others believe that acupuncture produces a chemical change in the bodys fluids. Still another theory is that the needles make contact with an unknown system of energy in the body which travels along certain routes under the skin. The true explanation may he one of these or a combination of more than one. Or it may be something entirely different. How long has acupuncture been practiced in China?