The "Onondaga Giant" is the work of the sculptor, and out of a single large block of the gypseous limestone (an upper member of the "Onondaga Salt Group") which forms large beds in the immediate vicinity. This stone is very strongly marked by lines of deposition, causing bands of different shades extending in horizontal layers, perfectly even and parallel through large quarry masses. In the present in stance these layers are so disposed--in the way the sculptor chose his block--as to cut lengthwise through the whole body, and to mark off different leads over the entire figure. Thus the left hip and left breast present (cameo-like) a layer different and higher than the one which forms the corresponding parts on the right side of the body. The head, too, with its different elevation of chin, nose and forehead, is very strongly marked in the same way. These linings are well-known peculiarities in the original deposition of a stratified rock, and are not features assumed in the petrifaction of any organic body. Further peculiarities of the Onondaga gypsum are very noticeable in the block, and among them is the peculiar style of decomposition by which the whole lower part of the figure is affected, as also one side of its head. Here the soluble earths, with any portions of carbonate of lime, have been dissolved away, and the pure granular sulphate (snowy gypsum) remains, standing up with ragged, uneven, cavernous surfaces, which is a feature very noticeable everywhere in weather-worn fragments of this rock. This decomposition or rotting of the lower side of the left leg gives a very vivid semblance to the corruption of actual flesh, and has doubtless had much to do with the ready reception which the "petrifaction" theory has found among the mass of visitors--even including many men of intelligence and general education. If such persons will refer to works which treat of petrifaction in all their various kinds of transformation and in all the thousand genera and species of fossil organisms, they will find that although bones, shells, and the hard parts of animals, changed to stone, yet preserving their original outlines, are of constant occurrence, yet there is not a single instance on record of fossil flesh; of the fat, muscle or sinew of man or beast changed into stone or into any substance resembling stone. To a person acquainted with the nature of petrifaction, the slow substitution of mineral for animal matter, particle by particle, the reason why humor of other flesh does not undergo the same change will be apparent. This is truly not entirely in accordance with popular belief, nor with the ever-recurring stories in our public journals. "A fish nearly a foot long, petrified to solid stone" has lately been cited in your columns as another instance of the petrifactions of the Onondaga Valley. I visited this yesterday at the Museum of the Onondaga Historical Society, at Syracuse, and found (what