...even when these statements are in the guise of testimonials. Explanation of Rule 2: Identification In order to avoid errors in the case of chemical compounds,...against adulterations, lack of potency or strength, and the mistaking of one chemical for another, it is necessary to have at hand suitable tests. Tests, etc....

...admitted, even if the false statement is subsequently corrected or omitted. Rule 2.—IDENTITY.—In order to avoid errors in the case of chemical compounds,...against adulterations, lack of potency or strength and the mistaking of one chemical for another, it is necessary to have at hand suitable tests. Tests, etc.—If...