Der Werth und die Geltung eines jeden Experimentes wird durch die Tauglichkeit der dazu benützten Hilfsmittel, sowie durch die zweckmässige Anwendung derselben bedingt.
The value and validity of any experiment are conditioned by the suitability of the means used for it, as well as by the appropriate application of the same.
means = Hilfsmittel Hilfsmittel is a very general term, including virtually anything used for a particular purpose, so both instruments, materials and sources of information. Bateson translates “material”, we follow Sherwood in our translation. A modern, and perhaps slightly anachronistic, equivalent would be “materials and methods”.