Remarks on the narrow limits of so-called rational medicine : read before the South Hants Medico-Chirurgical Society / by J. Stevenson Bushnan.

  • Bushnan, J. Stevenson (John Stevenson), 1808?-1884.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: Remarks on the narrow limits of so-called rational medicine : read before the South Hants Medico-Chirurgical Society / by J. Stevenson Bushnan. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    evidence, Imve the force of demonstration. If a metal lieatcd in a given quantity of atmospheric air, acquires Aveight, it is known, beyond doubt, without any further trial, that the weight which the metal acquires is exactly the same as that lost by the atmospheric air. If a given quantity of sulphate of baryta he heated with charcoal, the weight of carbonic acid produced indicates at once how much oxygen the sulphate of baryta has lost, or gives the proof that the sulphate is thus changed, not into a sulphuret of baryta, hut into a sulphuret of barium. If a given measure of water absorb a gaseous body—say ammonia—and the same mea- sure of the new compound is found to weigh less than that measure of water, it is demonstrated, without further proof, that the water has expanded in the operation. Again, if the exact relation between the length of the column of mercury, and the length of the column of water, which the atmospheric pressure suj)ports respectively in a vacuum he ascertained, the specific gravity of the mercury is inferred with absolute certainty—since a given bulk of mer- cury is as many times heavier than the same bulk of water, as the column of water is longer than the column of mercury, Or if the specific gravity of mercury be first known by some other means, and also the length of the column of mercury supported in a vacuum by the pressure of the atmosphere as in the barometer, then the length of the column of water supported in vacuo by the atmosphere is inferred with cer- tainty, because the column of water so supported is as many times longer than the column of mercury as the mercury is heavier than the Avater. Further, if it he found by actual trial that a column of mercury standing on a square inch and rising to thirty inches, Aveigh nearly fifteen pounds, then it is inferred Avith certainty that the equivalent column of Avaler rising to h(!tAV('on thirty-three and thirty-four feet, and