OF THE MEDICAL SCIENCES. EDITED BY ALEXANDER FLEMING, M.D., AND W. T. GAIRDNER, M.D. FEBRUARY TO DECEMBER 1848. WITH TWO LITHOGRAPHIC PLATES AND SEVERAL WOODCUTS. EDINBURGH: SUTHERLAND AND KNOX, GEORGE STREET. that, as the diameter of the nerve diminishes, its proportional cohesion in creases. I-MEDICAL PHYSICS, CHEMISTRY, AND NATURAL HISTORY. ARTICLE 1.-On the Elasticity and Cohesion of the Principal Tissues of the Human Body. By M. G. WERTHEIM.M. Wertheim, who has already published numerous determinations of the elasticity of inorganic substances, has now extended his experiments to the animal tissues. These experiments were made by loading a strip of the substance to be examined, of known length and diameter of section, with increasing weights, and measuring the increase of length in its extended state, and that to which it returned when the weight was removed, and finally ascertaining the weight required to produce rupture. The results of his experiments are contained in an extensive series of tables, for which we must refer to the original paper. The general conclusions deducible from them are the following. By dessication, the elasticity and cohesion of all the tissues increases, and approximates more nearly to that of inorganic substances.-Annales de Chimie et de Physique, December 1847. The specific gravity of the tendons, muscles, and veins, diminishes with age: But this change is not generally observed in the bones, nerves, and arteries. In the latter, owing to thickening and ossification of the coats, it is sensibly increased. The increment in length of a bone is proportional to the weight by which it is extended, exactly as is the case with inorganic substances, and wood; but this does not hold good with the soft parts in their natural state of humidity, the law of their increment in length being represented by a curve approximating to a hyperbola. Bones, tendons, and nerves, increase in elasticity with the age of the subject, but the reverse occurs in the muscles. The elasticity and cohesion of bones is greatest, then come tendons, nerves, muscles, veins, and arteries. The nervous trunks have, in proportion to their section, an amount of cohesion inferior to their immediate branches, and then again to the cutaneous nerves; so VOL. I.-NO. I. 2.-Professor ROGERS on the Absorption of Carbonic Acid by Sulphuric Acid.— At the meeting of Association of American Geologists and Naturalists, held at Boston in September last, Professor W. B. Rogers gave an abstract of a series of researches lately made by himself and Professor R. D. Rogers, on the absorption of carbonic acid by different liquids. In these investigations the important fact was ascertained, that sulphuric acid at 60° Fahrenheit, absorbs carbonic acid gas in the large proportion of 94 per cent., and that Nordhausen acid absorbs 125 per cent. Professor Rogers pointed out how this fact must affect the accuracy of certain methods of determining the amount of carbonic acid in the free atmosphere, as in the experiments of Boussingault and others, and of that contained in the air of mines, and in the air expired in respiration. The use of the sulphuric acid as a drying agent in these processes, as well as in the apparatus of Fresenius for analyzing the carbonates, was thus shown to be attended with serious errors, in consequence of the absorption of the carbonic acid by the dessicating agent. 3. Dr JOHN DAVY on the Urinary Secretion of certain Animals considered in connexion with their Temperature, Food, &c.-In birds, possessing of all animals the highest internal temperature, whether they be graminivorous or carnivorous, the urine consists chiefly of lithate of ammonia. A |