Neurons drawn by Ramon y Cajal. Courtesy of the Cajal Institute

Working alone at the turn of the 20th century in Spain, Santiago Ramón y Cajal (1852-1934) ventured into science as both an artist and a pathologist, and became the first person to see a neuron. Working by gaslight, he made thin slices of brain tissue and subjected them to the same silver-nitrate chemistry he used to capture images on photographic plates.

Cajal’s graceful drawings of neurons show them as separate, individual cells. He was the first to realize that the nervous system is not a network of continuous fibers, as was widely believed at the time.

The strange thing is that every one of Cajal’s immortal drawings is marred by an odd bit of deliberate vandalism: a blue cataloging stamp, often placed directly in the middle of the artwork.

In my article in Quanta, I take readers into the vault in Madrid where Cajal’s drawings, artwork, and scientific instruments are preserved.  I met the person who was responsible for the stamp placed on all of Cajal’s priceless artwork, and he answered the mystery of the curious blue stamp.  It was a building custodian who was responsible, and to him we owe much.

Read the story here:  Why the First Drawings of Neurons Were Defaced

Ramon y Cajal’s notebook. Note the blue stamp.
Courtesy of the Cajal Institute.