27 CHAPTER II. ON PETRIFACTIONS, OR FOSSIL ORGANIC Opinions of early Naturalists respecting Petrifactions.-On the Process called Petrifaction in some Instances rapidly effected. -Experiment of Dr. Jenner on the Petrifaction of recent Bones. Living Reptiles occasionally found in solid Stone.Remarkable Difference in the Condition of Fossil Remains in adjacent Strata; Instance of this at Westbury Cliff, Gloucestershire. The four grand Divisions of the Animal Kingdom.Distribution of the Remains of certain Classes and Orders of Animals in each Division through the different Rock Formations.-Remains of Monkeys hitherto undiscovered in a Fossil State. Observations on Fossil Organic Remains, as serving to identify Strata in distant Countries. IF it had been predicted a century ago, that a volume would be discovered, containing the natural history of the earliest inhabitants of the globe, which flourished and perished before the creation of man, with distinct impressions of the forms of animals no longer existing on the earth,-what curiosity would have been excited to see this wonderful volume; how anxiously would Philosophers have waited for the discovery! But this volume is now discovered; it is the volume of Nature, rich with the spoils of primeval ages, unfolded to the view of the attentive observer, in the strata that compose the crust of the globe. The numerous and varied forms of organic beings, whose remains are there distinctly preserved, often differ so much in structure from any known genera of animals, that we can scarcely hazard any probable conjectures respecting their modes of existence. Nor is it merely the forms of unknown animals that we discover in the different strata, we also learn the order of succession in which they were created. It is only within a comparatively short period, that these fossil organic remains have engaged the attention of naturalists. It is true that in remote times, the occasional discovery of shells and bones of large animals imbedded in rocks did not escape the attention of philosophers; but the shells were supposed to belong to species now living, and the bones to a gigantic race of men that perished during some great inundation, or had been buried by earthquakes. Other hypotheses equally remote from truth, serve to show how little attention had been bestowed on this department of Natural History. The celebrated botanist, Tournefort, from the regularity of form in many fossil remains, was induced to believe that they were stones that grew and vegetated from seeds. "How could the Cornu Ammonis," he observes, "which is constantly in the figure of a volute, be formed without a seed containing the same structure in the small, as in the larger forms? Who moulded it so artfully, and where are the moulds ?" As fossil organic remains, particularly shells and zoophytes, are found many hundred and even thousand feet below the present surface of the earth, the first inquiry that naturally suggests itself is, How did they come there? It is impossible that the animals when living, or their exuvia when dead, could pass through such vast depths of solid rock. A few of them might fall into vertical fissures, and remain there*, but they could never in this way enter into strata almost entirely composed of organic remains. Beside, the strata now deep under the dry ground, are chiefly filled with the remains of marine animals; nor do we generally find these animal remains confusedly aggregated; different genera or species occupy particular strata, or are associated with certain genera or species of the same class, and never with others. It is therefore evident that they were not brought into their present situations by vast in * Instances of oviparous reptiles found living in the midst of solid stone sometimes occur. At the colliery on Rothwell Haigh near Leeds, a living lizard or newt was found in a bed of coal at the depth of 180 yards from the surface. I saw it in the year 1819 soon after its discovery; it was preserved in spirits, and was about five inches in length. I could not perceive that it differed from the living species. The animal had probably crept into the mine along one of the levels that drain off the water, or down the sides of the shaft. In all instances where toads have been found in solid stone, it is reasonable to believe that they entered through fissures that have been subsequently closed. That these animals will live without food for a great number of years, is proved by the following circumstance. The late Sir Thomas Blacket, of Britton Hall in Yorkshire, had one cellar which was only opened once a year, as it contained some particularly choice wine which was never brought to table but on the annual celebration of his birth-day, which was on the 21st of December, or St. Thomas's day. The butler when taking out the wine, observed a small toad crawling along the stone floor. He placed the toad under a wine bottle, and thought no more of it till he went into the cellar the following undations, and buried under the earthy matter which a subsequent inundation cast over them. Neither could zoophytes, fish, or large reptiles, or the inhabitants of bivalve or univalve shells, have lived and flourished in the midst of solid stone. We are therefore led to the conclusion, that each stratum which contains these organic remains was once the uppermost covering of the globe, and that the animals for the most part lived and died near where their bones or shells are now found, and were covered by successive depositions of strata, in which following races of living beings flourished, and in like manner left their remains. Animal or vegetable substances are found im year, when on removing the bottle he was much surprised to see the toad immediately leap. This circumstance he mentioned to Sir Thomas, who descended with his visitors into the cellar to look at the toad; after which the bottle was replaced, and the poor animal was kept a close prisoner till the succeeding year, when he was again uncovered and found alive as before. The same annual experiment was continued for more than twenty-five years, when the wine was exhausted, the cellar cleared, and the toad, who was still living, was thrown out of doors. Having heard of this circumstance from a person who had lived in the family part of the time, I questioned the old butler respecting it, and he fully confirmed the truth of the story. It is much to be regretted that extraordinary facts relating to the natural history of animals should not be recorded immediately when they occur, otherwise they are soon forgotten, or are intermixed with fabulous additions which destroy the entire credit of the account. A few years after the death of the butler, I inquired of Mrs. Colonel Beaumont, the present highly intelligent possessor of the mansion, whether any written narrative of the above circumstance was preserved in the family; but she told me that she had never heard of it, as the fact occurred during her infancy. bedded in rocks, and are more or less impregnated with mineral matter, and hence have been called petrifactions. The process of petrifaction consists in the infiltration of mineral matter into the pores of bone or vegetables. In some instances the animal or vegetable matter has been almost entirely dissolved or removed, and the mineral matter so gradually substituted, as to assume the perfect form of the internal structure either of the plant or animal. The process of petrifaction may be more rapidly effected than has generally been supposed. In the year 1817 I paid a visit to the celebrated Dr. Jenner, at Berkley, who informed me that he had made several experiments upon recent bones, by burying them in the dark mud from the lias clay in less than twelve months the bones became black throughout, and when dry, they were harder, heavier, and more brittle than recent bone, and the surface was shining. The specimens which he showed me, presented the same appearance as the fossil bones in the lias clay. The effect was probably produced so speedily by the presence of the sulphate of iron, and other saline ingredients with which that stratum abounds. As this stratum is the most remarkable of all the secondary series, for the large animal remains which it contains, particularly of the saurian or lizard order, and as the bones are frequently covered with crystals or incrustations of pyrites, I will venture to hazard a conjecture respecting the manner in which these crystals, or incrustations of pyrites, or sulphuret of iron, are formed. The stratum before mentioned, contains sulphate of iron or green cop |