1890: Antitoxins - The book of science

Antitoxins
Humoral theory
Paraclete
Commentary

Emil von Behring, Shibasaburō Kitasato immunology

Antitoxins

Diphtheria bacilli
and tetanus bacilli
produce toxins
To protect themselves
infected animals
produce antitoxins
Emil von Behring
and Shibasaburō Kitasato
identified these antitoxins
and showed that trans-
ferring them to another animal
conferred immunity.

Humoral theory

That transferring serum
from the blood of a horse infected with diphtheria
conferred immunity to diphtheria in human beings
supported the theory that fighting disease
is the work of liquids in the blood
not of its cells
and had little to do with the four humors of ancient medicine
or maintaining a healthy balance of humors
by bleeding, cupping, emetics, or purges.

Paraclete

Blood, black bile, phlegm, and yellow bile,
according to the ancients,
mediate between the pure soul
and the impure body,
which, if it were balanced,
would be sure,
but I would rather a less messy cure,
a fresh breeze, a light rain,
the smell of a violet,
or a kiss on the cheek.

Serum is the liquid in blood that rises to the top of a test tube when left overnight, leaving blood cells and clotting proteins settled at the bottom. Paraclete is a word from the Greek for the Holy Spirit, but more generally means mediator or advocate.

Humoral theory is now discredited; cells produce antitoxins and perform other tasks in protecting animals from disease. Serum therapy was used to successfully fight diphtheria and tetanus, and Kitasato later developed an antitoxin for anthrax, but if you search for serum therapy today in wikipedia you get the article on vaccination.