the white silhouettes (if I may use the term) were made by the action of some light. If you wanted to copy them you had to copy them out of the light; otherwise the whole mass would get black, and that was the difficulty. In other words, the white impression could only be examined by candle or some other weak light, and they ultimately became shrouded in darkness and were lost--so we have now none of those pictures. While they were experimenting in England, a man named Niepse, a Frenchman, was at work upon the same subject--the action of light upon various materials, but in a somewhat different direction. In 1813, or probably before that time, he discovered that certain kinds of bitumen were soluble in oil of lavender, and that when you exposed these pieces of bitumen to some light the oil of lavender would not dissolve them any more. He conceived the idea (how, is not on record), but he thought that if he could coat plates with this bitumen and then expose them to light in a camera he could get a picture upon this bitumen, and where the light had acted the bitumen would be insoluble in oil of lavender. Where the light had not acted that he could dissolve it out. He proceeded to do this, and succeeded in getting pictures upon metal plates. He then, afterwards, etched the plates and thus got a perfect drawing or picture. So he used it simply as a means to produce a picture by etching. Now, understand, using the camera, he obtained an impression upon metal plates coated with bitumen. After exposing the plates in the camera he washed them in oil of lavender and then an etching fluid, and cut the impression into the matter and then they were printed. Some of these pictures are still in existence, they say. I have never seen any of them. After a time the plates were cleaned, and by the help of an etcher’s tools or an engraver’s tools they were cut still deeper and made very good engraving plates; so that his object was not simply to etch them but to produce plates for engraving.