There is a law of exact equivalence which pervades all nature. This law while perhaps most emphatic in mathematics, in music and in chemistry, is none the less true in the evolution of mineral, vegetable and animal development. The same is also true of all the various diseases when considered in relation to their antecedents.
It was not until the germ theory attracted the attention of scientists or rather was brought to light by scientists that much attention was paid to the antecedent of diseases; the effect was only considered and treated by our physicians. Each separate disease or ailment must be the equivalent of the producing cause, and any remedial agent that cancels or cures the disease must stand as the equivalent of the antecedent producing it. This proposition being correct, would lead us to first consider the importance and value of a prophylactic.
We all know that vaccination