But it is a negative, so called because everything in it is reversed—not only from left to right, but in the details of the image. Mother’s dark blue gown looks light, for example, and baby’s white dress, dark.
To get our picture as it should be, we must place the negative in contact with a sheet of paper coated with a gelatine containing silver. This emulsion, as the coating is called, is, as we might readily infer from the presence of the silver, sensitive to the action of light in much the same manner as was the original film. We place the negative and paper in contact, then, in what is called a printing frame, so that light may shine through the negative and impress the image on the sensitive paper. It is obvious that the light parts of the negative will let through the most light, and that consequently the silver emulsion on the paper underneath will be most blackened, while the dark parts will hold back the light and the emulsion on the paper underneath will be less affected. In other words, the very faults that we noted in the negative, from a picture point of view, automatically right themselves. Mother’s dress looks dark and baby’s dress white—just as the lens saw it.
We then have the picture in its finished form.
The story of the making of the camera is as interesting as that of the making of the pictures by the camera.
Back in 1732, J. H. Schulze discovered that chloride of silver was darkened by light and all unwittingly became the father of photography. In 1737, Hellot, of Paris, stumbled on the fact that characters written with a pen dipped in a solution of silver nitrate would be invisible, until exposure to light, when they would blacken and become perfectly legible. However, it was not until early in the nineteenth century that these two discoveries were put to any practical use, as far as photography was concerned.
Artotype Copy of the Earliest Sunlight Picture of a Human Face
Miss Dorothy Catherine Draper, taken by her brother, Prof. John W. Draper, M.D., LL.D., in 1840.
People of an artistic turn of mind had been in the habit of making what were called “silhouettes.” The sitter was so posed that the light from a lamp threw the profile of his face in sharp shadow against a white screen. It was then easy enough to obtain a fairly accurate silhouette, by either outlining the profile or cutting it out from the screen.
It occurred to a man by the name of Wedgwood that this profile might be printed on the screen by using paper treated with silver nitrate, and he not only succeeded in accomplishing this, but also in perfecting what was then called the “camera obscura,” the forerunner of the kodak of today. The camera obscura consisted of a box with a lens at one end and a ground glass at the other, just like a modern camera. It was used by artists who found that by observing the picture on the ground glass they could draw it more easily. Wedgwood tried to make pictures by substituting his prepared paper for the ground glass, but the paper was too insensitive to obtain any result. Sir Humphrey Davy, continuing Wedgwood’s experiments, and using chloride of silver instead of nitrate, succeeded in making photographs through a microscope, by using sunlight. These were the first pictures made by means of a lens on a photographic material. But none of these pictures were permanent, and it was not until 1839 that Sir John Herschel found that “hypo,” which he had himself discovered in 1819, would enable him to “fix” the picture and make it permanent.