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distinct attachment of a rib on both sides to each vertebra by a ball and socket-joint. It is remarked, that in this tribe of animals the relative positions of the ball and socket are reversed from their usual situation, the socket being attached to the extremity of the rib, and fitted to a protuberance from the body of the vertebra, instead of the extremity of the rib being applied to an indentation between two adjacent vertebrae. Hence the ribs do not in any degree interfere with the motion of the vertebrae upon each other, as in other animals.
The muscles by which these motions are performed, are also described by Mr. Home; but the distribution of them cannot readily be understood, Without reference to the drawings which accompany the paper.
At the termination of each rib is a small cartilage, which rests for its whole length on the inner surface of the corresponding abdominal scutum, to which it is connected by a short muscle.
The scutum being thus moved by a rib from each side, its posterior edge lays hold of the ground, and becomes the support by which the adjacent portion of the body is propelled forwards, and by a series of alternate motions is capable of renewing the impulse with considerable rapidity.
Mr. Home remarks, that in the Draco volans the wings, by which the animal flies, are supported by ribs, which form the skeleton of them; but in this instance the elongated ribs are super-added, for the sole purpose of forming the wings, and do not, as in the snake, assist in the process of respiration, at the same time that they are employed in giving progressive motion.
The principal objects of these experiments is to determine the proportions in which oxymuriatic acid or chlorine combines with various metals; but the author has also extended his inquiry to the relative proportions, in which oxygen also, and sulphur, unite with some of the same metallic substances.
Of copper, Mr. John Davy notices two compounds, to which he gives the names of Cuprane and Cupranea. The former is the same as the resin copper of Boyle, which may be obtained by heating together one part of copper with two parts of corrosive sublimate. This compound is also the same as that named by Proust, white muriate of copper, who obtained it by together muriates of tin and copper; and Proust observed that the same compound might be procured, by heat, from the common deliquescent muriate of copper.
This compound is fusible by heat below redness, and in close vessels is not decomposed by a strong red heat; but if air be freely admitted, it is dissipated in white fumes. It is insoluble in water, but
