MESSRS. EDITORS.Owing to the extreme state of isolation in which we exist, having communication with Upper California and the civilized world only at intervals of four or five months, I have just received my last batch of your journal since the 1st of December last. In the number for December 26th you give an abstract of the result of Dr. Hayes' experiments and observations on the conversion of uncrystallizable sngar(glucose and f ungin with melissic acid) into cane sugar, and state "the chemical change referred to Dr. Hayes pronounces to be something entircly new." This fact I discovered in the summer of 1856, in the course of a series of experiments on the generation of the alkaloid daturin ; and the facts were announced in the California press, and thence copied into several European jonrnals. These results were SUbjected to revision, and confirmation received of their correctness, in investigations instituted into the nature of the sugars of different varieties of datura and staphelia, the pomegranate, and various indigenous plants of the Peninsula, in the months of November and Deoember last. The saccharine secretions on concentration yielded in some instances a few concretions of irregular tabular crystals' of glucose, in others a gummy uncryst.allizable mass, polarized strongly to the left, and precipitated gold, silver and copper from their solution in the metallic state without the aid of heat. After an exposnre of a fortnight to atmospheric action I found the sirup filled with a mass of crystals, which appeared under the magnifier oblique rhombic prisms ; the solution precipitated nitrate of silver but slowly, and polarized strongly to the right. This change has, in the intervening period, affected more than 95 per cent of the original substance. I must not occupy yonr space in detailing the minuties of the experiments, but will add that the direct solar radiation greatly facilitates the conversion ; that the change proceeds very slowly, or not at all, in hermeti-cally-closed vessels ; and that I have hitherto obtained no clue to the cause of the phenomenon. R. L. D'Aumaile. La Paz, Baja California, May, 1858. [Although the remarks made by our correspondent are on a subject the discussion of which we have for some time avoided, we insert them, because they show that even in our western wilds there are persons who stndy science and obtain results as accurate and as valuable as any that are promulgated from our colleges of the north.Eds.