pound, and is to a certain extent oxidized in the epithelial tissues lining the lungs, is another factor which serves toexplain its slowness in producing anesthesia.

Dr. W. H. Porter estimates that each gramme of ether consumed in this way requires for its complete oxidation. about two and a half grammes of oxygen.

This condition of chemical combination consumes great quantities of oxygen, and like all processes of oxidation naturally produces great quantities of heat.

This heat irritates the centripetal nerve endings in the pulmonary organs, and accounts for the phenomena witnessed during the first stage of ether anesthesia.

It, too, serves as an explanation of why the heart and lungs are not apt to fail early, as sometimes occurs with chloroform.

It further illustrates why there is an apparent failureof respiration as the anesthesia becomes more pronounced. The centripetal nerves of the respiratory system have become somewhat exhausted from over stimulation, and hence, are losing their excitability; this condition continues until the reflex respiratory irritation ceases to be any longer a factor in keeping in action the medullary centers, which, from this point on, during the anesthetic state, must receive their stimulation from the irritation of the poorly oxygenated blood flowing through the medulla.

We are taught that the medullary centers are kept in motion primarily by irritation from the oxygenated blood, and that they are only secondarily influenced by reflex impulses received from without the centers.

Therefore, so long as the blood containing a requisite amount of oxygen continues to reach the medulla, the functional activity of the cardiac and respiratory centers will continue.

But when the necessary amount of oxygen, from any cause, is withheld from the medullary circulation, at once

the depressing influences of ether anesthesia become manifest, or, in other words, the danger line has been reached.

Here the ether should be withdrawn and the blood be allowed to renew itself again with the life-sustaining oxygen. Such, briefly, are the most generally accepted and, to my mind, the most reasonable conclusions as to the physiology of ether anesthesia.

No subject has been more widely discussed, no question more thoroughly investigated, but, unfortunately for the interest of true scientific knowledge, the discussions have principally consisted in the enunciation of individual opinions, which have generally convinced none but the originators of investigations largely limited to the field of theory, and therefore inconclusive and of no practical importance in clinical medicine.

In my humble judgment the physiology of ether anesthesia has been given undue prominence, to the neglect of the more important practical aspects of its proper administration.

No amount of purely theoretical investigation can ever take the place of extended clinical experience and careful personal observation.

Nearly all the theoretical conclusions on the physiological effects of ether have been the results of experiments upon the lower animals, and not upon human beings.

Every physiologist will readily admit that in anesthetizing the human being certain factors come into play which are not met with in the lower animals.

The administration of an anesthetic is after all more a practical matter than a theoretical condition. This being true, the only opinions that are entitled to any great weight and consideration are those which are the results of large personal experience in the operating-room, and not from theoretical deductions-the evolution of the physiological laboratory.

ETHER VERSUS CHLOROFORM.

BY WM. H. ELLIOTT, M.D., SAVANNAH, GA.

In some cases the choice of an anesthetic is made for the surgeon, because one or the other may be contraindicated, or because one may be known to be so safe in certain classes of cases that its use is generally endorsed by the profession.

Chloroform is considered safe in children and in obstetric practice. It is contraindicated in large, weak or fatty heart, and it is said to be especially dangerous where orthopnea exists. It goes without saying that chloroform must be promptly discontinued in any case where alarming symptoms attend its use.

Ether is contraindicated in prolonged operations about the face and mouth, in affections of the genito-urinary system, in valvular disease of the heart, in stenosis of the larynx or trachea, and generally in affections of the respiratory organs, in cases of fracture, where the struggles of the patient may lacerate the tissues and possibly convert a simple into a compound fracture, in abdominal operations because of its liability to cause excessive vomiting, and lastly, in those cases of emergency in which an operation has to be performed a short time after a solid meal.

Moreover, ether is dangerous in the presence of the actual cautery and open artificial light.

But the question I am to discuss is not which anesthetic is best adapted to any particular case, but which one should we adopt for general use in ordinary cases. The

answer should be the safer one, and it would seem a simple thing to accept the answer given by the statistics and the medical profession of the north, and say ether.

But do the statistics settle the question? So far as figures go it would seem that they do. Before accepting this conclusion, however, some facts must be taken into consideration.

The chief danger in the administration of chloroform is from paralysis of the heart, and the risk is greatest at the beginning of the inhalation; the more concentrated the vapor the greater the danger. When the patient is so far under the influence of the anesthetic as to breath easily and regularly, this danger is pretty well over and then comes the danger of failure of respiration. This is a dan

ger

of lesser degree, because paralysis of the heart is usually sudden, and that without remedy; while failure of respiration is likely to be gradual in its approach and is more amenable to treatment. It is to be noted here that deaths from chloroform occur during the administration and will always be charged to the anesthetic.

In ether, on the other hand, the chief dangers are not during the inhalation but after, and come in the form of respiratory or genito-urinary complications, especially suppression, and occasionally there is unaccountable collapse. Should a fatal result ensue it would be more likely charged to disease than to the anesthetic.

Some years ago an important suggestion bearing on this question came from Dr. H. C. Wood of Philadelphia, a great authority on anesthesia. He learned from a physiologist that dogs responded to anesthetics differently in this country and in Europe. This led him to suggest that chloroform might be safer in a warm climate. Certainly the experience of the southern surgeon with the Confederate.

soldier would seem to favor the truth of this idea. More recently, in Dennis's System of Surgery, Dr. Wood says:

"There is very great reason for believing that chloroform is less lethal in hot climates than in colder regions. The British surgeons of India aver with one voice that they can administer it without evil effect. The anesthetizers of the extreme southern or gulf tier of American States are almost equally urgent in claiming safety for the use of chloroform, whilst on the continent of South America it is solely employed, again with alleged freedom from ill effect." He adds: "The only explanation of these facts which seems to me plausible is that at high temperatures chloroform vapor diffuses very rapidly, and consequently escapes from the blood and from the lungs with extraordinary rapidity." To settle this question finally we must have further statistics from the surgeons and hospitals of the South.

Holding the views that I do in regard to the dangers of chloroform, I must caution the administrator to give this powerful anesthetic very slowly at first, in a well ventilated room, and with the vapor largely diluted with a plentiful admixture of air. This last can best be secured by using a coarse towel with a large mesh. I here enter my protest against the common custom of telling the patient to take deep inspirations. This is especially dangerous at first, and is just the way to overwhelm the heart by an overdose of the vapor.

Later on when the danger is through failure of the respiration, the administrator must watch the breathing and the capillary circulation with an intentness that will allow no interruption or distraction. The eye should note respiration and complexion, and the finger be kept on the temporal artery.

So far as I can judge then, it is in the power of the ad