We have already noticed the method recommended by Professor Cossar Ewart of preserving fresh fish with boracic acid and salt. Mr Roosen of Hamburg has patented another method, which was lately tested in Edinburgh. The process consists in the salmon being placed in an air-tight compartment among a solution of boracic acid, salt, and water, and a heavy pressure being applied, the solution penetrates and thoroughly disinfects the fish, which are prevented from decaying, and retain all their strength and nourishment. On the 15th of February, a steel barrel, made for the purpose, and capable of holding about three hundred pounds of fish, was filled with salt water containing about fifty per cent. of boracic acid, and into this compound five splendid salmon, fresh from the Tay, were placed. The air having been entirely withdrawn, the barrel was hermetically sealed, a pressure of six atmospheres, or ninety pounds to the square inch, being applied. After standing for seventeen days, the barrel was opened on the 4th of March, and all the salmon were found in as fresh and healthy a condition as when they were first placed among the solution. The flesh of the fish was of a beautiful colour, and could not be distinguished from that of a fresh salmon placed alongside of it, while the blood began to flow freely immediately on the salmon being cut up. The salmon was served up at a luncheon, on the following day, in different forms of cooking, and the general opinion was that the new method of preservation was upon the whole successful. The fish was of good flavour and colour; it could be separated in nice flakes, and the curd was well preserved. A NEW BOILER-FEEDER.