126 REPOKT — 1869. 



nitrous protoxide, or " laughing gas," in London hospital practice. This " gas," 

 at first condemned from mere experiments on rabhits as the most deadly of all the 

 anaesthetics, proves to be in man the least deadly. In one hundred thousand cases 

 there has been perhaps no death due to the gas itself. One or two accidents have 

 been noted in dental practice from foreign bodies, loose teeth, or the cork used 

 to keep the jaws asunder slipping into tlie relaxed glottis. This gas neither 

 enters into combination with the blood, as ether for instance, nor does it produce 

 change in the blood as carbonic oxide, nor is it changed itself; it is, in a word, 

 quite passive, and offers to the notice of physiologists, the author believes, a pas- 

 sive agent, taking the place of atmospheric air in the lungs. 



As to the physiology of common " sleep," opposite instances were cited of sleep 

 from venous congestion, and sleep from vascular anaemia. In sleep the pupils are 

 contracted in children and fontanelles depressed. The ophthalmoscope, too, bears 

 out Mr. Durham's theory of anasmia ; or, is it because we sleep, the brain becomes 

 anffimic (independent of vaso-motor or ganglionic action, as urged by Mr. Moore) ? 

 Sleep is the chief remedy in delirium tremens ; and here digitalis is superior to 

 chloral as a remedy. 



Even the spectroscope can detect no change in the blood when the nitrous 

 oxide is inhaled — indeed there is not sufficient time in the forty or fifty seconds 

 during which the gas begins to act before sudden asphyxia takes place, for the 

 complex changes to occur supposed by Dr. Marcet and others ; even the same ten 

 gallons of gas thus unchanged may be inhaled over and over again by the same 

 patient with like results of complete insensibility, going off almost in a moment 

 when the inhalation is stopped, and atmospheric air allowed into the lung. The 

 author in previous memoirs in the ' Transactions,' from observation in London 

 hospitals in over 20,000 cases of chloroform administration, papers read at New- 

 castle, Oxford, &c., was led to doubt that the principle on which the Clover 

 apparatus, that of cardiac syncope, is constructed is always true, so that patients 

 die of cardiac exhaustion in every instance ; he thinks now, if any fact or sugges- 

 tion were wanting to complete the proof, it is this cardiac exhaustion under this 

 gas far greater than under chloroform, and yet the patients invariably recover in 

 three to four minutes ; the pulse under chloroform never sinks, it rises ; the pulse 

 under this gas gradually sinks till it is almost imperceptible. 



The iustantaneousness of the insensibility and tlie waking up are not unlike the 

 falling asleep under ordinary sleep ; deficient oxidation runs parallel with the sleep, 

 but the change is a "vital" one; oxidation alone will no more explain it than 

 explain a fit of chorea or epilepsy. The microscopic examination goes deeper, and 

 shows the blood-corpuscles and brain, or gi-ey matter (protagon) , altered by one set of 

 anresthetics but not by others ; the author, in fine, concludes that deaths from 

 chloroform are more frequent from emotion or fright on the part of the patient 

 than cardiac exhaustion from deficient oxidation. 



Experiments with methylene on animals, or chloral or ether "mixtures," so 

 strongly recommended from theoretic ideas by the Eoyal Medical and Chirurgical 

 Society (though previously abandoned in Austria, where they had been enforced 

 by government authority), experiments with the nitrous oxide, on the supposition 

 that it is more dangerous than terchloride of carbon, with voltaic narcotism, 

 or with some patent mixture or ether, are experiments that frighten patients and 

 lessen their faith in simple chloroform, and things that cause confusion, founded 

 on the theory of deficient oxidation alone, and have only retarded the progress of 

 anaesthetics ; nor is a fatty heart one of the chief sources of danger, at least as far 

 as is shown by 300 cases of deaths from chloroform collected by the author from 

 journals, — mostly cases of healthy adidt men attacked with sudden apncea from 

 alarm or fright at viewing the preparation of kni^"es, saws, &c. for the operation, 

 the tears and grief of friends, &c., or of men who were bad subjects for opera- 

 tion, with healthy heart, from the presence of delirium tremens, want of sleep, 

 want of food, &c. The Association would now confer a great benefit on the public 

 if these 300 or .350 cases were carefully tabulated, and the deductions as to age, 

 sex, disease, character of accident (apncsa or asphyxia), post-mortem result, &c. 

 were marked out. Electricity to the diaphragm has proved in many late chlo- 

 roform cases most valuable, since the idea of apncea, in place of fatty heart, has 



