The “Troy Times” understands that Mr. Hill has perfected his discovery, so far .as regards transferring all the color by a single operation. The only desideratum remaining is an aid in reducing the time required for making pictures from thirty minutes, to, if possible, lees than as many seconds. A similar difficulty, but not so serious, occurred in the bringing out of the daguerrean discovery. Iodine, &c, were found to answer the purpose for the latter, but Mr. Hill has to deal with many colors, and a chemical that serves with one, may spoil or prove useless without the other. The stick is now on the yellow.— [We saw the above in a great number of our daily papers 1-st week. It certainly looks like the old story, as the " stick " has always been on the yellow.