practically confined to the processes of M. Testud de Beauregard, MM. Gamier and Salmon, and Mr. Pouncy.
The decision of the Commission was, that the process of MM. Gamier and Salmon and that of Mr. Pouncy were about equal in result, the latter requiring, however, an exposure of nearly four times as long as the former; but being at the same time simpler in manipulation. M. Poitevin had not entered the competition or contributed specimens; but recognizing in him the originator of all the processes of carbon printing, the Commission felt bound to acknowledge his merit. Instead, therefore, of awarding the whole amount as one prize to any individual, it was resolved to divide it, awarding a gold medal, value 600 francs, to M. Poitevin as the originator of carbon printing; a similar medal to MM. Davanne and Girard for contributions to the improvement and stability of silver prints; a silver medal, value 400 francs, to MM. Gamier and Salmon, for their carbon printing process; and a similar medal to Mr. Pouncy, for his process.
A further prize of 2000 francs, offered by the Due de Luynes for the same purpose, was awarded to M. Poitevin in 1862. In 1867 he received the prize of 8000 francs, offered for the best mechanical printing process with fatty ink, based upon photography.
Early in 1864, a suggestion for the production of carbon prints was made by Mr. Obernetter, of Munich. In his process, paper is treated with a solution of sesquichloride of iron, chloride of copper, hydrochloric acid, and water. After drying, the paper is exposed under a negative, and then developed in a solution of sulphocyanide of potassium, sulphuric acid, a little of the sensitizing mixture and water, and then washed. The image is formed of sulphocyanide of copper: if the print be exposed to an atmosphere of chlorine, the image is con-
