Masks Worn during Experiments with Plague. Manila, Philippines (1912)

In 1912, the Philippines was a colony of the United States and had been so since 1898, following the Spanish-American War. At the time, the U.S. was in the process of trying to establish control over the Philippines, which involved a number of military conflicts and a great deal of social and political upheaval.

In terms of the bubonic plague, it was a significant public health concern in the Philippines at the time, and the government was taking steps to control its spread. This would have included measures such as quarantine, hygiene education, and the wearing of masks by those conducting experiments and treating infected individuals. The bubonic plague, also known as the "Black Death," was a highly contagious and often fatal disease caused by the bacterium Yersinia pestis. Masks worn during experiments with the disease would have been designed to cover the mouth and nose, and to prevent droplets from the wearer's breath from spreading the disease.

In terms of symbolism and spiritual meaning, masks have often been associated with ritual and protection. Wearing a mask during experiments with the plague would have conveyed a sense of fear and caution, as well as a desire to protect oneself and others from the disease. In some cultures, masks have also been seen as a way to ward off evil or to purify the self. Overall, the Philippines in 1912 was a place of significant change and challenge, as the country was in the midst of a difficult transition from Spanish colonial rule to American colonial rule.