A liquid-drop generator providing discrete stringerless drops of simulantsor use in testing chemical warfare detectors. The generator system is provided with two syringes in which one contains a highly viscous, non-newtonian liquid and the other contains water. The two syringes communicate with a capillary. When a pendant drop of non-newtonian liquid is formed on the terminal end of the capillary, the ejection of water or air into the capillary frees a discrete stringerless droplet from the terminal end thereof.