On this day (September 16) in the year 1852, the following article appeared on page 1 of the "Boston Daily Evening Transcript": - - - - - - - - - - - - - COLORED DAGUERREOTYPES. A communication in the National Intelligencer announces that W. Niepce St. Victor, nephew of Daguerre, has made the discovery of colored Daguerreotypes, and exhibited his pictures to the public. Three of his pictures are now before the public in London, and the new art is called heliochromy, or sun- coloring. They are copies of colored engravings, the one a female dancer, the other male figures in fancy costumes; and every color of the original most faithfully impressed on the prepared silver plate. In the proceedings of the Paris Academy of Sciences, the following account of the discovery is given: The idea struck young St. Victor that there was some relation between the color which a body communicates to a flame and the color the light develops on a plate of silver which had been chlorinated, and he therefore commenced a series of experiments to test its correctness. He knew that strontium gave a purple color to alchoholic flame; he therefore prepared a plate of silver by passing it through water saturated with chlorine and the chloride of strontium. He then applied the back of a drawing, containing red and other colors, against the plate, and exposed the whole to the light of the sun fifteen minutes, when the colors of the picture were produced on the plate, but the red one far better defined than the others. To produce the six other rays of the solar spectrum, the same method used to produce the red color is followed with other substances. The chloride of calcium for an orange, the chloride of soda of potassium, or pure chlorine, for yellow; and beautiful yellows have been produced by a solution of hydrochloric acid and a salt of copper. The green ray was produced by boric acid and the chloride of nickel; the blue ray was obtained by a double chloride of ammonia and copper, and a white ray with the chloride of strontium and sulphate of copper. A silver plate, prepared with water acidulated with hydrochloric acid and the battery, gives all the colors by the action of light, but the ground of the plate is always black. St. Victor found that all the substances which produced colored flames produced colored images by means of light. The plate upon which to produce these effects must be prepared with very pure metallic silver. The baths are made, one- fourth, by weight, of chloride and three-fourths of water. After the plate is well polished by tripoli and ammonia, it is immersed in a bath at one stroke, and allowed to remain a few minutes. It is then removed from the bath, rinsed in clear water, and held over a spirit-lamp till the plate becomes a cherry color, at which point it is exposed to the light in the camera. It takes two hours of exposure, but the process will yet be shortened. The whole process, to be successful, must be nicely managed. -------------------------------------------------------------- 09-16-97