ANESTHETICS. 



19 



i o years devoted to examination and experi- 

 ment in connection with the anaesthetics in use, 

 reported during July, 1864 ("Lancet," July 

 16; "Amer. Jour, of the Med. Sciences," 

 Oct., 1864). This committee urge the dangers 

 attending the deeper degrees of the effect of 

 chloroform, and they concede much in favor 

 of ether, as that in the outset it is not so 

 purely depressing, and that at the same degree 

 of insensibility it does not to the same degree 

 depress the heart's action, as chloroform. Ke- 

 garding chloroform as in a degree hazardous, 

 and ether as inconvenient, they suggest that 

 some more eligible anaesthetic is still to be 

 desired. In chloroform inhalation, they think 

 that 44- per cent, of rapor, with 95 per cent, 

 of air, is the maximum that can be required ; 

 3J per cent, of vapor being a suitable average. 

 They do not find that anaesthetics have in- 

 creased the rate of mortality. 



Painful dental operations, especially the ex- 

 traction of teeth, occupy in reference to the 

 use of anaesthetics a sort of middle ground, as 

 admitting of resort either to general or to 

 local anaesthesia. In any case, owing to the 

 extreme sensitiveness of the dental nerves, 

 and the excruciating pain the extraction (at 

 least) of the teeth occasions, the anaesthetic 

 action requires to be very decided, and the 

 state of insensibility profound ; and it is cer- 

 tainly supposable that this circumstance consti- 

 tutes an explanation in part of the compara- 

 tively greater mortality (already referred to) 

 from chloroform and ether in dental practice. 

 During the past fifteen years or more, resort 

 has been had, unavailingly, to mesmerism ; to 

 the congelation or freezing of the gums, which 

 however was found liable to be followed by 

 rheumatic pains in the part, or other diffi- 

 culties; and to the passage of an electrical 

 current through the nerve at the moment of 

 seizing and extracting the tooth: but these 

 methods have in succession been laid aside ; 

 and though the two last named have been 

 revived from time to time, almost or quite 

 to the present date, by individual practition- 

 ers, they find no favor with the profession at 

 large. 



In the early part of the year 1863, Dr. G. Q. 

 Colton revived the use of nitrous oxide as an 

 anaesthetic in dental operations. He states 

 (Dec., 1864) that he has successfully adminis- 

 tered the gas to more than 3,000 patients, and 

 that in no instance has he known any ill effects 

 to attend the operation. He prepares the gas 

 by heating nitrate of ammonia in a retort, and 

 collects it in a barrel, from which it displaces 

 water previously contained its purification 

 being completed by letting it stand for some 

 hours over a remaining portion of the water. It 

 is of the utmost importance that this gas should 

 be perfectly pure ; and it is presumed to be so 

 when a little of it inhaled by way of test does 

 not excite cough. The gas is inhaled through 

 a tube from a rubber bag, the contents of 

 which only the patient respires for the time, 



the nostrils and the corners of the mouth 

 being closed. About six gallons are used for 

 one inhalation; the anaesthesia is usually in- 

 duced in about one minute's time, and passes 

 off in a like or less period. Two or more teeth 

 may in the mean time be extracted ; and after 

 waiting a few minutes for the bleeding to sub- 

 side, the dose may be repeated ; and so on, several 

 times in succession, if required. The rubber bag 

 should in every case be emptied and cleansed 

 before receiving a new charge. If not in all 

 respects, still, a wholly desirable anaesthetic, it 

 would nevertheless appear that nitrous oxide is 

 at once the most agreeable to the patient, and 

 the most safe (at least for the brief operations 

 in which it has been employed) of the general 

 anaesthetic agents now in use. Dr. A. C. 

 Castle ("Boston Med. and Surg. Journal," 

 March 3, 1864) mentions three cases in which 

 its employment was followed by decidedly un- 

 pleasant symptoms, in the head, the chest, and 

 the nervous system, respectively, and in per- 

 sons previously in good health ; but the gene- 

 ral testimony of those acquainted with its use 

 appears to show that such results are rare. 

 The agent is already employed by many den- 

 tists in New York and Xew England, if not 

 also in other parts of the country. 



Various forms of local application of chloro- 

 form or ether, or of their vapors, have been 

 resorted to for the purpose of securing local 

 anaesthesia, but usually with uncertain, and 

 often with very incomplete, success. Perhaps 

 the most efficient of all these has been M. 

 Eichet's modification of M. Guerard's process 

 in its simplest form merely letting ether 

 fall, drop by drop, on any external part to bo 

 benumbed, and playing on it at the same time 

 with the current of air from a common bellows. 

 M. Founder's " chloracetization " application 

 of chloroform and glacial acetic acid has been 

 found often to occasion too much irritation 

 and smarting to allow of its use. Chloroform 

 applied on lint or in test-tubes for ten or fifteen 

 minutes sometimes produces total insensibility. 

 The process of congelation, by applying a 

 freezing mixture of pounded ice and salt, and 

 which is familiar to medical men, is still earn- 

 estly recommended by many authorities, for 

 superficial operations; though in this confi- 

 dence Prof. Gross does not share. Dr. Arnott 

 ( " Med. Times and Gazette," quoted in the 

 "Boston Med. and Surg. Journal," Oct. 1, 

 1863) has recently repeated his recommenda- 

 tion of artificial cold, both as an anaesthetic, 

 and for the relief of inflammations : and he 

 proposes a new method that of cooling in a 

 freezing mixture, and to below Fahr., an 

 iron, brass, or copper instrument of suitable 

 form, or two such to be used alternately, and 

 applying on the part to be benumbed. The 

 local application of carbonic acid for the relief 

 of pain has not been attended with su< 

 As to passing an electric current through the 

 nerve of a tooth at the time of extraction 

 effected by placing one pole of a battery of 



