A notebook records a malaria clue

He noticed a fluorescent screen glowing during cathode-ray experiments in Würzburg.

His laboratory observation launched tests of a phenomenon later called X-rays.

The observation preceded the first famous hand radiographs and later clinical use of X-rays.

Once developed, the new radiation allowed physicians to see bones inside the living body without surgery.

While working in British-ruled India, he observed pigmented structures in the dissected mosquito.

The date later became World Mosquito Day, commemorating a result reached in India rather than Britain.

The work depended on Indian settings, patients and assistants, although standard retellings often focus almost entirely on Ross.

In Lassance, he found the parasite now called Trypanosoma cruzi in the blood of two-year-old Berenice.

The young patient was the first documented human case of the disease later named after Chagas.

Chagas connected a parasitic organism, an insect vector and a human case in his research.