On page 411, Vol. XII., of the SCIENTIFIC AMERICAN, and in subsequent numbers, we expressed our opinion that crystallizable sugar was not obtainable from the Sorgho cane. We did so, having the authority of eminent chemists and practical refiners to support our opinion; and as far as they had examined, they were right. But neither they nor we had gone quite far enough, for we have received a sample of beautiful crystallized sugar, prepared by Mayland Cuthbert, of Philadelphia, also some samples of the same from E. G. Ward, of New Bedford, Mass., equally good. We carefully examined them and were at a loss to account for it. Has the great problem of converting syrup into sugar been solved ? thought we ; it cannot have been. We were in an inexplicable difficulty concerning this phenomenon until we saw a communication in the Prairie Farmer, from Dr. Ostrander, of Lexington, 111., whose experiments, if confirmed by subsequent investigations, seem to solve the difficulty. He says :— " I purchased a sugar (crushing) mill of two iron rollers, 5J inches in diameter, and 14 inches long, and had new gear wheels cast, both of a size, to give equal motion to the rollers. I commenced grinding and boiling, and soon found that six gallons of juice would make one gallon of superior syrup. I then built a mill with wooden rollers, 18 inches in diameter, and went at it in good earnest, and found that it now took eight gallons of juice for one of syrup. Upon investigating the cause, I found there were two jnices distinct from each other in the cane, viz.: a crt/slalli-zable and an uncri/stallizable saccharine juice. The iron rollers expressed both, the wooden rollers only one. The juice run from the iron rollers granulated easily, while the juice from the wooden rollers could scarcely be said to grain. My cane was twice frozen solid before it was worked or cut." The above announcement will stimulate additional researches into the nature of the Sorgho plant, and we shall hope to see Dr. Ostrander's position carefully tested. If found to be correct its future value for sugar-making will become a question of importance in an economical point of view. FRENCH SILK MANUFACTURE—The production of cocoons in France has been diminished from about 58,500,000 pounds in 1853, to about 15,750,000 in 1856. The aggregate production of silk in the world is estimated at a value of $200,000,000.