ANESTHETICS. 



15 



and the agent was thereupon abandoned. Dr. 

 Ozanam, in his recent revival of inhalation of car- 

 lonicacid to produce insensibility, administered 

 it along with common air, 3 parts to 1. He 

 found this mixture safe ; and it produced com- 

 plete anesthesia, from which the patient recov- 

 ered without difficulty ; but it does not appear 

 that the use of this agent has yet become in any 

 manner general. The condition of trance, som- 

 nambulism; or artificial sleep, as induced in con- 

 nection with the agencies or methods of influ- 

 ence passing under the names of " Mesmerism," 

 "animal magnetism," "Braidism" or "hypno- 

 tism," "psychometric impression," "spiritual- 

 ism," &c., has been of late years often resorted 

 to, and in some of these forms for a time much 

 vaunted ; but though in exceptional cases, or in 

 the hands of particular persons, painless sur- 

 gical operations have been doubtless secured 

 tinder some or all of the influences named, yet 

 their effect is far from uniform, or even cer- 

 tain ; and at the present day, none of them are 

 relied on as suitable to take the place of the 

 material anaesthetics. 



Dr. Valentine Mott, in his monograph upon 

 "Pain and Anaesthetics," prepared at the re- 

 quest of the U. S. Sanitary Commission (Wash- 

 ington, 1863), in considering the philosophy of 

 of anaesthetics, and their value to the surgeon, 

 justly remarks, not only that pain is useless, but 

 also that it is positively injurious to the pained ; 

 and he cites from difierent authorities the ex- 

 pression of a truth which is stated by Gooch, in 

 the words, "Mere pain can destroy the powers 

 of life." But when complete insensibility exists, 

 both pain and nervous shock are, so far as the 

 operation is concerned, avoided. " The most se- 

 vere operation during anaesthesia," says Dr. Mott, 

 ."produces little or no effect upon the pulse, 

 because the nervous centres receive little or no 

 impression." But again, except where the con- 

 scious cooperation of the patient with the sur- 

 geon is required, and in all cases in which the 

 locality or peculiar nature of the operation may 

 not forbid the administration of anaesthetics, 

 the unconsciousness, helplessness, and complete 

 relaxation which those agents can produce, is 

 often a matter of the highest convenience and 

 advantage. The use of anaesthetics thus allows 

 the surgeon to undertake cases in which, with- 

 out them, he could not safely think of oper- 

 ating; and it also allows him to take more 

 time. Considerations such as these show that 

 their employment practically extends the do- 

 main of surgery; and moreover that, primd 

 . it should lessen the danger and the mor- 

 tality of operations. 



Dr. Detinold, in 1847, M. Ozanam later, and 

 some other medical authorities, have argued 

 that in the inhalation of ether, chloroform, or 

 other anaesthetics, the insensibility obtained is 

 due to action of carbonic acid resulting from 

 the decomposition of such substance within the 

 system. M. Ozanam went so far as to say that 

 carbon is in all cases the true anaesthetic ; and 

 that so-called anaesthetic agents possess their 



power just in the proportion that they are more 

 largely composed of carbon. But if this were 

 true, amyleue should be a more potent anaesthetic 

 than ether, and ether itself than chloroform; 

 whereas the reverse is true in both cases. 

 Again, the experiments and observations of 

 Flourens and Longet go to show that the spe- 

 cific anaesthetic agents, not less than morphine, 

 strychnine, alcohol, &c., produce their effects 

 by a direct and positive depressing action upon 

 the nervous centres. Thus, they are all (save, 

 perhaps, nitrous oxide and even on this point 

 there is room for question) positive poisons; 

 and in undue quantity they produce death in 

 that mode (naturally, and usually in fact) in 

 which we say it begins in the nervous system. 



Nitrous oxide, by freely yielding oxygen, is, 

 like common air, only in still higher degree, a 

 supporter of combustion. Of course, in the 

 outset of its inhalation, it is in proportionate 

 degree a supporter and quickener of the func- 

 tions of life. By hurrying on decomposition in 

 the system, it rapidly generates carbonic acid, 

 and loads the blood with this product. Ether 

 is not a supporter of combustion, but is com- 

 bustible; and its decomposition may to some 

 extent increase the proportion of carbonic acid 

 naturally contained in the blood. But chloro- 

 form is neither a supporter of combustion nor 

 combustible ; and it is doubtful whether it un- 

 dergoes decomposition in the system at all. 

 All anaesthetics, however, after a preliminary 

 stage of excitement, longer or shorter, then 

 forthwith begin, by inducing a torpor or in- 

 activity in the nervous centres, to depress and 

 to lower the respiration, if not also the heart's 

 action ; and as a consequence, they occasion the 

 retaining for the time in the blood of much of 

 the carbonic acid, naturally forming in the 

 system, which would under a normal respi- 

 ration be continually expelled. Still further, 

 wherever gaseous anaesthetics are administered 

 by means of a containing reservoir or bag. so 

 that the patient breathes the same material over 

 and over, even the carbonic acid which is ex- 

 pelled, for the time, mingles with the anaesthe- 

 tic, increasing in quantity, and being reinhaled. 

 These facts would show, that with chloroform, 

 there is a single source of increase of carbonic 

 acid in the blood this being, however, not 

 the cause, but the consequence, of the anaes- 

 thetic action; that with ether, there are two 

 such sources ; while with nitrous oxide, there 

 are three sources of increase of carbonic acid. 

 And unquestionably the retained carbonic acid 

 will contribute its share to the depth of the 

 stupor that results; if, indeed, in the case of 

 nitrous oxide alone, it may not be in a large 

 degree the really effective agent. At all events, 

 it is probable that the action of carbonic acid, 

 generated or retained in the blood during anaes- 

 thetic inhalation, may in some cases modify 

 materially the symptoms attending or following 

 upon then- use. 



The stages of anaesthesia are strictly com- 

 parable to those of intoxication (carried to 



