It took 150 years for the result!!

Posted on: October 9, 2006

The chemist John Dalton, who framed the atomic theory, was color blind. He started thinking of the reason of his colorblindness. He thought it probable that the fluid that fills the eyeball behind the lens (termed as Vitreous humor) was tinted blue, unlike the colorless fluid of normal eyes.

Dalton proposed that after his death his eyes should be dissected and the color of the vitreous humor determined. After his death in July 1844, physician Joseph Ransome dissected his eyes and found the vitreous humor was perfectly colorless. Ransome thought, the cause of colorblindness lies beyond the eyes and he preserved the eyes in a jar.

In 1994, after the death of Dalton’s death the experiment he started was finally finished. Molecular biologists of England took a small sample of Dalton’s retina and extracted DNA. Using the known gene sequences for the opsin gene of the red and green photopigments, they amplified the relevant sequences and found that Dalton had opsin gene for only for red photopigment, but not for the green photopigment. Dalton was greendichromate.

It took 150 years for the final result!!


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