This extensive kingdom of Nature presents us with a variety of objects
destructive to human life; their agency, however, is on many occasions
involved in impenetrable obscurity, and we are not even able to discover
whether their deleterious effects depend upon certain definite
principles, or upon the combination of circumstances connected with the
individuals upon whom they act; and which thus render many substances
_relatively_ poisonous, that are innocuous to the general mass of
mankind. With regard to the chemical laws by which animal compounds are
governed, and the principles upon which their analysis may be conducted,
the same observations will apply as those with which we introduced the
consideration of vegetable poisons.
Cl. IV. SEPTIC POISONS.