Jaundice Vitamin D production. Bilirubin count is lowered through bowel movements and urination, so frequent and effective feedings are especially important. Yellow discoloration of the skin, especially on the palms and the soles, but not of the sclera or inside the mouth is due to carotenemia—a harmless condition. Jaundice itself is not a disease, but rather a sign of one of many possible underlying pathological processes that occur at some point along the normal physiological pathway of the metabolism of bilirubin in blood. When red blood cells have completed their life span of approximately 120 days, or when they are damaged,
Hand-colouring of photographs 1839. Coloured powder was fixed on the delicate surface of the daguerreotype by the application of heat. Variations of this technique were patented in England by Richard Beard in 1842 and in France by Étienne Lecchi in 1842 and Léotard de Leuze in 1845. Later, hand-colouring was used with successive photographic innovations, from albumen and gelatin silver prints to lantern slides and transparency photography. Parallel efforts to produce coloured photographic images affected the popularity of hand-colouring. In 1842 Daniel Davis Jr. patented a method for colouring daguerreotypes through electroplating, and his work was refined by Warren Thompson the following year.