Hass v. Marshall

Per Curiam,

So far as the tests made by the rejected witness were concerned, they might have been admitted in evidence, for they were facts of which any one who had sufficient knowledge of them might have testified. But it does not follow that the person observing or making them was an expert chemist. Before anyone is allowed to testify to the character of a substance, he certainly ought to be required to have some knowledge of its constituents and be able to tell what is its legitimate constitution, otherwise he cannot intelligently pronounce upon its adulteration. It follows, that the witness proposed as an expert, not being so qualified, was properly rejected.

The judgment is affirmed.