sitter this metallic plate, and I have here one of just such plates. Now, into this plate-holder are fitted “kits” as we call them to hold different sized plates. Unfortunately part of this apparatus is lost; _i.e._, to say all these little details of kits, but they could all be made out of little pieces of wood. Now, the daguerreotype is this: They take a silver-copper plate (a piece of copper plated with silver. When they first did this, they used to solder upon copper plates a piece of silver, then put it in a press and roll it out. After that time, in latter years when the galvanic battery had been discovered and was in common use, they electroplated it). Now, this particular plate was put into a holder that was held like that. Now the small boy was given one of the buffers or he was put at a wheel that had upon it a backing of felt and on the front of it was chamois leather (it is now long gone on this one--been rubbed off). This plate was then rubbed with a great deal of dexterity and you had to be very careful that you did not scratch it. That was the most important thing about them. It spoilt the picture if you scratched them. They had to be perfectly smooth. As I said, this was sometimes done by holding the plate on a wheel, but the ordinary way was by using one of these buffers. The silver plate was taken out by undoing this screw at the corner. Now, the first thing to do with it, then, is to make it sensitive. It is merely a silver surface now. It was made sensitive by placing it in one of these boxes (showing it) called coating boxes. Now that plate was put into that box (showing the same box), and see there is the lime in the box and it is now probably forty years old, having never been disturbed. In that lime was placed bromine, and it was then covered with a glass cover that fits over this glass trough or dish--it is rather deep. This was then placed with a little pressure--in order to keep the box tight and not let the bromine fumes get all over the studio--and they put the plate in here and pulled this over, so, leaving it there a certain number of minutes, and by action of the bromine vapor it becomes coated with bromide of silver. Then they either put some iodine into this same box or they had an iodine box. After the plate was in there a few minutes, they took it out and put it in there and gave it a dose of bromine. It was found, and by whom I am not sure, that the addition of a little iodine or a small proportion of iodide of silver with iodine of silver gave better effects. So it was then taken out and it was sensitive to light. Now, Daguerre discovered all that. This was then put in the plate holder and exposed in the camera and he got a picture. And it bothered him a great deal, for it faded. If he put that hypophosphite of sodium on it that our friend Herschel discovered, it cleaned the whole picture off. There was not enough of it. So he watched and watched and was weary with making these pictures and having