Abstract: A method and device for testing a liquid such as urine for obtaining at least qualitative, but also quantitative, if desired, information in connection with a substance which may be present in the liquid. A reference body and at least one test body are dipped into and removed from the liquid which is to be tested, a suitable means being connected with the bodies to facilitate the dipping thereof into and the removal thereof from the liquid. The test body is capable of giving a color indication in connection with the substance while the reference body has characteristics substantially identical with those of the test cody except that the reference body is incapable of giving a color indication in connection with the substance. Thus, after removal of the bodies from the liquid the reflectivities thereof may be compared so as to give at least a qualitative, but also a quantitative, if desired, indication of the substance in connection with the liquid which is tested.