Item:
Water sight feed flow meter (O2, CO2, N2O) with chloroform & ether bottles

Date of manufacture:
circa 1920

Manufacturer:
Coxeter.

Description:
The flow meter system to the left would have had a plain glass jar, filled with water to the level of the bar. Below that bar, each flow meter down-tube is perforated at intervals with holes. In use, increasing gas flow would depress the water in the tube causing gas to escape from increasingly low holes. These levels were calibrated in units of flow which would be read from a card attached to the bottle. The chloroform vaporiser bottle is coloured green while the ether bottle is clear. It is not known why the glass is coloured green,as the recommended colour for bottles for storing chloroform is brown. The chains would have been attached to the filler corks to prevent accidental loss.

Note that there are no needle valves to control individual flows. Flow control would have been achieved by adjusting the cylinder valve. Early flow controllers (20110016) would later be replaced by Adams valves (20110051 & 20110053) used in conjunction with Coxeter bobbin flow meters that included needle valves (20110018)

Boyle vaporisers - early design. The vaporisers are of an early design. Later, Boyle introduced the plunger for use on ether vaporisers that redirected the through-vaporiser gas flow to bubble through the liquid anaesthetic and cause the output vapour concentration to be maximised. He also invented the outer metal reservoir to combat the excessive internal cooling that occurrs with these vaporisers.

Category:
flow control

Accession Nr.:
20110025
.
Discussion:
This assembly is similar to the system attached to the earliest Boyle's "outfit" except for the addition of the chloroform vaporiser. The "outfit" first appeared in 1917 as a modification of Gwathmey's (USA) Nitrous oxide, ether and oxygen machine. It was subsequently repeately developed by Boyle. Chloroform was added in 1920.

References:
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