Description: Segment 1 A map of South America is shown, with the locations of curare, a crude extract from the bark and stems of certain plants. Curare paste is shown. The intertitles explain that one of the active constituents of tube-curare has been isolated as a chloride (drug name D-tubocurarine). The chemical structure of this is shown, as well as the powder form and the drug. An experiment is carried out using a rat diaphragm to show how the drug works. The rat's diaphragm is removed and immersed in Ringer-Locke solution. It is electrically stimulated to make the muscle contract. Curare is applied to the nerve. Then neostigmine is added. The effects of the drugs are recorded and explained by the intertitles. An animation shows how d-tubocurarine works. An animation shows how the antidote, neostigmine, works. Time start: 00:00:00:00 Time end: 00:07:32:19 Length: 00:07:32:19 Segment 2 The intertitles explain what muscles are affected by d-tubocurarine. A male volunteer is injected with the drug and the effects are observed and explained using intertitles. The patient is made to stand and clearly has difficulty. Next, the clinical uses are discussed. Electrical shock therapy on a female patient on a bed is shown. First, it is shown without the use of d-tubocurarine. Her arms stretch out involuntarily a doctor holds her feet. Treatment is shown again on the same patient this time the patient receives d-tubocurarine. It blocks muscle response to nerve stimulation. An animation shows how it works. Time start: 00:07:32:19 Time end: 00:16:13:11 Length: 00:08:40:17 Segment 3 The intertitles and animations explain how d-tubocurarine aids anaesthesia. Another use for the drug is shown during an operation for stomach cancer. The male patient is anaesthetised. D-tubocurarine is injected. The abdomen relaxes fully. The operation is successful and the patient is shown ten days later, sitting up in bed and smoking. Time start: 00:16:13:11 Time end: 00:23:26:03 Length: 00:07:12:17