In the early 20th century, a curious invention emerged from the depths of scientific exploration: the Kilner screen. These glass slides or plates, coated with a toxic coal tar dye called dicyanin, possessed an extraordinary ability to reveal the invisible realm of ultraviolet (UV) light. While their applications were diverse, from capturing the ethereal beauty of UV spectra to venturing into the realm of aura photography, the Kilner screen’s legacy is intertwined with the risks it posed.

The origins of the Kilner screen can be traced back to the inquisitive mind of Walter John Kilner, a British chemist fascinated by the properties of dicyanin. He discovered that when glass was treated with this dye and then exposed to UV light, the glass would fluoresce, emitting a vibrant blue glow. This phenomenon, known as fluorescence, opened up a new avenue for exploring the unseen world of UV radiation.


One of the earliest applications of the Kilner screen was in the field of UV photography. Scientists employed these screens to capture images of the UV spectrum, a portion of the electromagnetic spectrum that lies beyond the visible range of human eyes. These images revealed the unique patterns and characteristics of UV light, allowing scientists to gain a deeper understanding of its properties and applications.


However, the Kilner screen’s allure extended beyond the realm of science. It also found a niche in the burgeoning field of spiritualism and psychic research. Aura photography, the practice of capturing images of the purported ‘aura’ surrounding a person, gained popularity in the early 20th century. Believers in this phenomenon claimed that the Kilner screen could enhance the visibility of auras, revealing the subtle energy fields that supposedly emanate from individuals.

Aura photography, however, never gained scientific acceptance. There is no credible evidence to support the existence of auras, and the images obtained using Kilner screens were often dismissed as artifacts of the photographic process or the subjective interpretations of the photographer. Nevertheless, the Kilner screen remained a popular tool among amateur photographers and spiritualists seeking to capture the ethereal essence of the human spirit.

Despite their fascinating applications, the Kilner screen’s legacy is clouded by one major drawback: the toxicity of dicyanin. This coal tar dye, the very substance that enabled the screens’ fluorescent properties, also posed a significant health risk. Exposure to dicyanin could lead to skin, eye, and lung damage, as well as nausea, vomiting, and respiratory problems.

Consequently, the use of Kilner screens gradually declined in the mid-20th century as concerns about dicyanin’s toxicity grew. While they served as a valuable tool for exploring the early days of UV photography and aura research, their limited applications and inherent health risks ultimately led to their discontinuation.

The Kilner screen remains a fascinating chapter in the history of science and technology, a testament to human ingenuity and the pursuit of understanding the unseen. While their legacy is marked by both innovation and risk, they serve as a reminder of the potential both perils and triumphs that can accompany scientific exploration.