The cessation of respiration under chloroform, and its restoration by a new method / by R. Milne Murray.

  • Murray, R. Milne (Robert Milne), 1855-1904.
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: The cessation of respiration under chloroform, and its restoration by a new method / by R. Milne Murray. 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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    pressures, it is capable of recording accurately much greater variations than Marey’s instrument can indicate. In the latter instrument the limit of elasticity of the rubber membrane is soon reached, when increments of pressure fail to effect proportionate movements of the lever. Thus the characteristic features of many tracings demanding such record are lost. The special nature of the tracings obtained by this instrument will appear further on. I have explained that the chloroform was adminstered by means of the second T tube. The concentration of the vapour was regulated by the size of the receptacle for the chloroform and the diameter of its neck. The same size of tube was always employed; and if this were dipped into a narrow-necked bottle containing a large quantity of chloroform, the vapour would be in its most concentrated form, whereas were it placed in a large jar containing a small quantity of the anassthetic on cotton wool, the vapour would be in a dilute condition. Further, the quantity given could be still further diluted by admitting a larger quantity of air by the tap, and by cutting off some of the vapour by partly closing the pinch-cock on the chloroform tube. I made some experiments by having a Wolff’s bottle attached to the main tube, and by connecting the registering apparatus to the other neck of the bottle; but as the results of several experiments did not vary from those of the simpler apparatus, I abandoned this arrangement as being needlessly cumbrous. From such an arrangement it will be seen that every inspiration will draw air out of the tambour, and will be indicated by a fall in the lever, while expiration will force air into the tambour, and will cause a rise of the lever. In the case of the records obtained by the manometer, the opposite is the case. The fall of the lever represents an expiration and the rise an inspiration. The apparatus having then been arranged as described, the animal was allowed to breathe air alone until signs of returning reflex appeared. The respiratory rate now generally fell to 7 or 10 respirations in 10 seconds—i.e., from 40 to 60 per minute, varying chiefly according to the size of the particular animal. The clock was now started, and a tracing of the respiration taken for 10 or 15 seconds. The chloroform tube was then dipped into the receptacle, and the moment noted on the paper. In many of the tracings, the respiratory movement was recorded continuously until cessation. In others (these extending over several houis) the respiration was taken before and after each change in ad- ministration or withdrawal, and at regular intervals of time. In this way I could note the effects of concentrated and dilute vapour, given continuously or intermittently, and I have there- fore observed the mode of respiratory cessation under the follow- ing conditions:— 1. The continuous administration of the concentrated vapour. 2. The alternate administration of concentrated vapour and an.