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Graphs of precipitin reactions illustrating effects of formalin on antigenicity and reactivity of the extracts.

The precipitin test depends on a somewhat analogous reaction.

Some precipitin tests and preliminary remarks on the systematic relationships of four South American families of frogs.

No white precipitin, as it is called, would form.

The precipitin reaction is the most successful of the serological techniques thus far devised for systematic comparisons.