Report on the progress of human anatomy and physiology in the year 1843-4 / [Sir James Paget].

  • James Paget
Date:
1845
Catalogue details

Licence: Public Domain Mark

Credit: Report on the progress of human anatomy and physiology in the year 1843-4 / [Sir James Paget]. Source: Wellcome Collection.

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    in food, fuel, and lighting, in Paris, lie estimates the daily produce of carbonic acid at 115,932,871 cubic inches; and the speedy diffusion of such a quantity is not surprising, when it is added that the surface of the ground “ within the walls” of Paris measures 1354,229,533 square inches ; so that if the whole of the carbo¬ nic acid produced in twenty-four hours, were produced in an instant, it would form a layer on the surface less than an inch in thickness. To this it may be added, on the authority of Mulder,* * * § that the results, similar to the above, which were obtained by De Saussure, as to the quantity of carbonic acid contained in the atmosphere at various times and places, have been confirmed by Verver, whose experiments, like those of Boussingault, were performed by means of Brunner’s aspirator. He says also that he has instituted examinations to determine the quantity of ammonia in the atmosphere, and that it is so ex¬ tremely small, that it is not possible that plants should derive their nitrogen from it; it is not more important, as a constituent of the atmosphere in its relations to the organic kingdom, than many other of the innumerable substances that are ex¬ haled into the air, and brought down again with the rain.f But if this be true, there must be differences in the quantity of ammonia in the atmosphere of different places, which is very improbable. For Dr. John DavyJ has found traces of its presence in several samples of rain-water collected at Ambleside ; [and in many fogs in England, it may be detected by the action of the air on slightly reddened and moistened litmus'paper. In London fogs it is evident to the nose and eves ; and, as in these, so about Ambleside, it is probably brought down with soot, for Dr. Davy describes a layer of carbonaceous matter, like particles of soot, often covering wide extents of the surfaces of the Westmore¬ land lakes. Such layers are abundant enough on the surface of water in London ; after a night of still frost, great quantities of soot might be swept from the surface of the ice. May we not suppose that the minutely-divided carbon which floats in the atmosphere, is constantly disinfecting it by absorbing not ammonia alone, but many other gases, and holding them in its pores till it falls, or is washed down by rain, and yields them to be decomposed by plants ?] It would be beyond the limits of this Report, to enter far on the subject of the purification of the atmosphere from the changes produced by respiration. It must suffice to refer to the papers of Prof. Draper,§ Dr. Gardner,|| and Mr. Hunt,5] (especially to that of the first,) on the decomposition of carbonic acid by plants, under the influence of those rays alone of light, which occupy the most luminous part of the spectrum, the orange, ijellow, and green rays ; and to the observations of Wohler** and Morren,f f on the removal of carbonic acid, and production of oxygen, by certain of the minutest and most abundant infusoria. ANIMAL HEAT. An extensive series of observations has been made by M. Roger on the temperature, of children in health and various diseases. In nine examinations of infants from one to twenty minutes after birth, the temperature, (observed in these and in all the other cases, in the axilla,) was from 99-95 to 95 45. Immediately after birth the temperature was at the highest; but * Physiol. Scheikunde, pp. 113, 160. t Mulder considers that the real source of the nitrogen of plants is in the ammonia formed by the combination of the nitrogen of the moist atmospheric air, contained in the porous earth, with the hy¬ drogen given off from the decaying organic compounds. By a similar process, ammonia is formed by the decomposition of water and atmospheric air in all porous bodies, provided they are moist and ex¬ posed to the air at a certain temperature; a similar production of ammonia from water and atmos¬ pheric air is a part of the process by which nitre is formed in many natural nitre-caves. 1 Edinburgh New Philos. Journal, July, 1844. § Philosophical Magazine, Sept. 1843, and many subsequent parts. || American Journal of Science and Arts, Jan. 1844 ; and Edinb. New Philosoph. Journal, July 1844 ^ Philosoph. Magazine, 1843-4, various parts. Annalen der Chemie und Pharmacie, Bd. xlv, p. 206; aud Schmidt’s Jahrbuch. Oct. 1843, Bd xl. tt In Mulder, Physiol. Scheikunde, p. 117 t and Ann. de Chim. et de Phys. Sept. 1844. 14 Arch. Gen. de Medecine, Juillet, A6ut, &e. 1844.