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and preceded by the signs of returning consciousness, which indi- 

 cate the rcadniinistration of the anaesthetic agent, and enable the 

 surgeon thus to anticipate interruption. Protract the inhalation yet a 

 little longer, and the inspiration becomes a snore ; the pulse, "which 

 may or may not have been previously accelerated, beats slowly; 

 while the pupil is frequently, though not invariably dilated. 



Some little familiarity with these phenomena is required to 

 enable the surgeon so to graduate inhalation as to continue the 

 patient in this state of tranquil and deep sleep with safety. 



There is no doubt that it can be done if necessary. I have fre- 

 quently myself maintained insensibility nearly or quite complete 

 for thirty minutes, and even for a longer period. While the snore 

 is heard, the patient does not revive ; yet the snore is an unnecessary 

 symptom, and is an indication for the temporary suspension of in- 

 halation, when a few inspirations of unadulterated air soon re-esta- 

 blish quiet respiration; and the patient is liable, at any moment, to 

 swallow or give other indication of approaching consciousness. The 

 cumulative effect of ether, before alluded to, is at this time to be 

 borne in mind. Young subjects, too, require less than adults; so 

 that after eight or ten minutes of insensibility in the adult, or a 

 considerably shorter period in the young subject, the system has 

 been impregnated with ether, and inhalation may be discontinued 

 even before the snore is heard, without apprehension that the sub- 

 ject will rapidly recover. The signs of returning consciousness are 

 the limit on one side of that degree of anaesthesia, which it is im- 

 portant to maintain during most surgical operations, and are indi- 

 cations for the reapplication of the inebriating agent, when it is 

 desired to protract insensibility. 



At the other limit of the second stage of anaesthesia, is a far more 

 important indication of over-narcotized vitality ; and here is the pro- 

 tection against danger. Without this safeguard, I conceive that it 

 might well be hazardous to overshadow animal existence by this 

 mysterious and powerful agency. The sign is the diminution of the 

 force and frequency of the pulse. 



In a case of the early administration of ether, at which I was 

 present, and which has been reported, the danger from over nar- 

 cotism was quite as imminent as in any case, not fatal, I have seen 

 since alluded to. As a bystander, on that occasion, I casually felt 

 the pulse, and found it barely distinguishable; and though it subse- 

 quently still decreased, the means at once adopted for the restoration 

 of the patient, proved ultimately successful. This occurrence pointed 



