The calibration of the Waller gas balance and the Connell anaesthetometer / by W.M. Boothby and I. Sandiford.

  • Boothby, Walter M.
Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: The calibration of the Waller gas balance and the Connell anaesthetometer / by W.M. Boothby and I. Sandiford. Source: Wellcome Collection.

    11/14 (page 377)
    D = 0.716 T = 4 A' = 1.2282 grams weight of air at 780 mm. and 21°, air 40 per cent saturated with water vapor, M = 6.5 per cent. 0.1542 X 0.716 X 4 0.4416 + 1.2282 [4 + (4 X 0.065)] weight of ether and alcohol. 0.4416 5.6737 = 7.78 per cent by To change percentages by weight to percentages by volume, allowing for the alcohol content of ether, the following procedure is necessary: Alcohol content of ether = 3% by weight 7.78% X 0.03 = 0.23 per cent alcohol by weight 7.78% X 0.97 — 7.55 per cent ether by weight 1 L ether at 780 mm. and 21° = 3.1531 grams 1 L alcohol at 780 mm. and 21° = 1.9601 grams 1 L air, 40% saturated at 780 mm. and 21° = 1.2282 grams 0.23 grams alcohol = 0.117 L = 0.15% by vol. — 1.17 mm. tension of alcohol 7.55 grams ether = 2.394 L = 3.09% by vol. = 24.1 mm. tension of ether 92.22 grams air = 75.085 L 3.24% by vol. = 25.3 mm. tension of alcohol 100.00 grams mixture — 77.596 L an<t ether In order to get such close agreement between the calculated tension and the true tension, it was necessary to slightly modify the Connell meter by introducing a Muller water valve in the air vent between the vaporizer and the ether container. If this pipe is freely open, ether diffuses back through it, thereby increas¬ ing the delivered mixture by 5 to 10 mm., depending on the amount of heat that is conducted to the ether container from the electric heater under the vaporizer. From the table, it is seen that ordinary barometric and tem¬ perature variations affect the tension very little. The follow¬ ing calculation shows that the vapor tension of ether as delivered by the apparatus likewise adjusts itself to barometric changes due to an elevation above sea-level: