1928 · Frederick Griffith
The Significance of Pneumococcal Types
What this work is
Griffith's 1928 paper on pneumococcal types. He injected mice with heat-killed smooth pneumococci of one type together with living rough pneumococci of another. Some mice died, and smooth colonies of the dead strain's type grew from their blood. He called the change transformation.
Then and now
Griffith showed that dead smooth pneumococci injected with living rough ones could leave smooth colonies in a dead mouse's blood. Molecular biology made his transformation the first step in the proof that genes are made of DNA. He never named a substance, and nobody has seen a gene.
Verdict
UNSCIENTIFIC
The work only partly follows the scientific method inside its paradigm, and the paradigm itself does not pass. The worse layer decides. The verdict is unscientific.
1·This work · inside the paradigm
MIXED
Partly follows the scientific method within Germ Theory.
2·Paradigm · Germ Theory
UNSCIENTIFIC
Fails the tests. The worse layer decides.
How the verdict is decided
The verdict grades both layers: the paradigm this work assumes, and how the work was carried out inside it. Both must be scientific for the whole thing to be scientific. A clean method inside an unscientific paradigm is unscientific. An unscientific method inside a better paradigm is unscientific. A split on either layer is mixed. The worse layer decides.
1·This work
Did this work test its claim with methods that are independent, falsifiable, and non-circular?
MIXED
This work claims that dead smooth pneumococci of one type, injected into mice together with living rough pneumococci of another, transform the rough strain into the virulent smooth form of the dead strain's type. The tests split.
Independently Verifiable
Fail
The dead mouse and the smooth colonies from its blood are visible, but the step that makes those colonies 'Type I' is clumping in a serum raised from cultures already called Type I.
Falsifiable
Pass
Dozens of mice stayed well and produced no smooth colonies, and Griffith printed those failures in his tables, so the transformation could simply have failed to happen.
Non-Circular
Fail
The Type I serum was made from cultures classified as Type I by that same serum, and that serum is then the only evidence the new colonies are Type I rather than reverted Type II.
Why
The colonies are visible, but they become Type I only by clumping in serum raised from cultures already called Type I. Many mice stayed well and produced no smooth colonies, and those failures sit in his tables. That same serum is both the definition of the type and the only evidence the new colonies belong to it.
2·Paradigm · Germ Theory
Does the framework this work assumes pass the three tests?
UNSCIENTIFIC
Independently Verifiable
Fail
An injected animal dying and colonies growing from its blood are visible, but a 'serological type' exists only as clumping in blood serum the typing system itself produced.
Falsifiable
Fail
Griffith himself says a Group IV strain found in sputum 'does not prove that strain to be the cause of the disease,' so an organism without illness is read as carriage, never as disproof.
Non-Circular
Fail
Animals were immunized with cultures classified by agglutination, and the resulting blood serum then served as the standard proving that agglutination sorts bacteria into real biological races.
Why
Germ theory rests on a visible event: inject an animal with a cultured organism and the animal sickens; grow the organism from its blood afterward. That much a stranger can watch, and Griffith's mouse experiments run on it. What the framework adds on top is this paper's entire vocabulary: the serological race, the S antigen, the type as a stable thing a bacterium belongs to. Those exist only as clumping in blood serum built from earlier typing. And when a strain shows up in a healthy throat, the field says carriage rather than disproof, a move Griffith himself makes about Group IV strains in sputum. The organism gets named as the disease. What made the host open to it is never the question.
From the work
The mouse was killed when ill 3 days later and smooth virulent Type I pneumococci were growin from the blood and from the subcutaneous seat of inoculation.
It must, however, be re- membered that the isolation on a single occasion of a Group IV strain from a sputum, especially in the later stages of the pneumonia, does not prove that strain to be the cause of the disease.
though agglu- tination was of the rough character, i.e. the deposit was readily shaken up, it occurred up to the full titre 1 in 160 of a smooth Type I serum.