The administration of nitrous oxide and oxygen for dental operations / by Frederick W. Hewitt.

  • Hewitt, Frederic W. (Frederic William), Sir, 1857-1916.
Date:
1901
Catalogue details

Licence: Public Domain Mark

Credit: The administration of nitrous oxide and oxygen for dental operations / by Frederick W. Hewitt. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    the Societe de Biologic, on Feb. 9th, 1878, he stated'^ that he found the effects of toxic gases upon Hving organisms to be dependent upon their tension when breathed. Nitrous oxide was a gas which, at the ordinary atmospheric pressure, would only produce anaesthesia when administered pure, i.e., free from air. Un- fortunately, however, in administering nitrous oxide free from all air, asphyxial phenomena soon become developed. But if a mixture of one half nitrous oxide and one half air were administered in a closed chamber in which the ordinary barometric pressure could be doubled, then the blood would receive just as much nitrous oxide as when the gas was adminis- tered pure at ordinary pressures, and just as much air as would be breathed under natural circumstances. In this way prolonged anaes- thesia would be possible and asphyxia pre- vented. As we shall subsequently see, Bert's original proposition as to the necessity of em- ploying perfectly pure nitrous oxide for the production of anaesthesia was not true. He soon saw, moreover, that by using oxygen instead of air it would be unnecessary to dilute the nitrous oxide to anything like the extent above indicated, so that a compara- tively small increase in barometric pressure would be needed. On the nth May, 1878, Bert stated^ that