A treatise on the tonic system of treating affections of the stomach and brain: comprehending an account of the causes and nature of impairment of the constitution, indigestion, determination of blood to the head, impairment and morbid excitation of the brian, paralysis, apoplexy, and insanity / [Henry Searle].

  • Searle, Henry.
Date:
1843
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the tonic system of treating affections of the stomach and brain: comprehending an account of the causes and nature of impairment of the constitution, indigestion, determination of blood to the head, impairment and morbid excitation of the brian, paralysis, apoplexy, and insanity / [Henry Searle]. Source: Wellcome Collection.

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    Density of the Atmosphere. When the den¬ sity of the atmo¬ sphere is great, neither rain nor moisture de¬ scends ; on the contrary, the buoyancy of the air occasions the speedy ascent of moisture from the earth by evapora¬ tion. When the den¬ sity of the atmo¬ sphere is much reduced, its buoy¬ ancy is diminish¬ ed, allowing the moisture in the higher strata to coalesce into clouds, and to de¬ scend in the form of rain. Temperature. If the tempera¬ ture be very high, the evaporation will be rapid, and both the surface of the earth and the atmosphere will become dry, and the weather sultry and cloud¬ less, as in tropi¬ cal climates. If the tempera¬ ture be moderate, the exhalations from the earth will proceed less rapidly. If the tempera¬ ture be very low, little or no evapo¬ ration will go on, and the air will be ^dry and frosty. If the tempera¬ ture be high, the elasticityofthe air will be brought into operation, which will in a slight degree counteract its de¬ ficient buoyancy; and if the atmo¬ sphere be still, it will be highly charged with e- lectricity. If the tempera ¬ ture be moderate, considerable eva¬ poration and de¬ scent of moisture taking place at 4 the same time, the whole atmo¬ sphere, especially the lower strata, will be highly charged with hu¬ midity. The tempera¬ ture and density of the atmosphere can never be at theirlowestpoints at the same time; but often in this climate the den¬ sity is inferior when the tempe¬ rature is only ten or fifteen degrees above the free¬ zing-point. Diseases induced. f A very high temperature of the atmosphere produces general vascular excitement, occa¬ sioning profuse perspiration, swelling of the extremities, vertigo, syncope, hemorrhages, phrenitis. To this over-excitement succeed emaciation, lassitude of body and mind, fevers of various kinds, liver affections, &c. A dense air counteracts, in a slight degree, the tendency [to some of the above diseases. f To these states of the atmosphere, unless preceded by exceedingly cold weather, it would be difficult to ascribe any pernicious influence, , whether upon a sound or impaired condition of ' the whole or of any part of the human frame; but when preceded by frosty weather, they are abundantly productive of inflammations of the [_air-passages, hemorrhages, rheumatism, &c. [ Cold, by its sedative agency, diminishes the circulation of the blood on the surface and ex¬ tremities of the body, and occasions in aged people apoplexy, palsy, and sphacelus of the feet; in others, inflammatory affections of the internal organs, diarrhoea, and other functional disturbances. In certain asthmatic patients a dense atmosphere, by its weight upon the inner J surface of the air-cells, overpowers their al- j ready diminished resilience, and thereby in¬ creases the dyspnoea. This form of the disease is improperly denominated spasmodic asthma, and is erroneously considered to arise from constriction of the air-cells, whereas these ca¬ vities are most probably in an opposite condi¬ tion—in a state of forced distention, owing to the increased pressure upon their internal sur¬ face. v_ A warm and impoverished state of the atmo¬ sphere induces languor in invalids, and in per¬ sons of lax fibre; those subject to rheumatism, to chronic affections of the brain or of the joints, are sensible of its effects. It is also fa¬ vourable to dropsy and hemorrhages. It has been stated that certain asthmatic pa¬ tients suffer under a dense atmosphere, while a warm and rarified air relieves them ; it dis¬ tresses those who are subject to other forms of the same disease, the dyspnoea being increased in consequence of the combined effects of vas¬ cular excitement occasioned by a high tempe¬ rature, and of muscular relaxation resulting from deficient density of the atmosphere. The effects are, turgescence of the blood-vessels, and consequent contracted calibre of the air-pass¬ ages, accumulation of mucus, increased weight of the lungs, and relaxation of the air-cells. Mild wet weather, especially if it succeed frost, occasions inflammation of the lungs, la¬ rynx, fauces, and nares; rheumatism, hemor¬ rhages, drcpsies, and defluxions of all kinds. There are but few diseases of the inflamma¬ tory and febrile classes wTiich may not result from exposure to this unfavourable weather ; * but those organs which are predisposed by prior disease are the most liable to inflammation from such a cause. The occurrence or the sup¬ pression of hemorrhages may arise from the re¬ vulsion of blood which takes place from cold feet.