Appendix to Second report of the Commissioners : minutes of evidence, February to March, 1907.
- Great Britain. Royal Commission on Vivisection (1906)
- Date:
- 1907
Licence: Public Domain Mark
Credit: Appendix to Second report of the Commissioners : minutes of evidence, February to March, 1907. Source: Wellcome Collection.
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![is the particular discoverer of any new discovery ; that there are several just on the point of discovery. Was anybody on the point of discovering by clinical obser- 4677. It would assist him in knowing what theexact M.A. R. condition of his patient was and what remedies he Cushy, ought to apply ?—Yes, indicating that he ought to be M.A., M.D, vation what these other gentlemen discovered by experiment ?—No, I think not. Traube had clinical interests; he worked as a clinician, and his work in physiology was largely suggested by his clinical work ; and he went to animals to work out how digitalis acted, in fact, because he evidently failed to do so in his patients. Brunton’s interests, of course, were always clinical, and apparently he went to animals in order to explain the problems he could not solve in patients. 4669. He was not satisfied of the accuracy of the ‘theory about the action of digitalis before him ?— Yes, that is what I understand. The danger of trust- ing exclusively to clinical examination for therapeutic advance may be exemplified by the same drug. It is undoubtedly of value in certain forms of pneu- monia, and is useless or deleterious in others. If it were adopted in all cases the mortality statistics would probably be scarcely different from those of cases not treated with it, and the result would be the experimental methods, however, directs the clinician’s attention to this phase of pneumonia in relation to digitalis, and the finds that the statistics of cases of pneumonia in which the heart is involved are improved by digitalis. 4670. These experiments of Brunton and Schmiede- purposes in general physiology, but they were experi- ments directed specially to the action of digitalis ?— Yes. 4671. You have told us what they discovered, and you say that further experiments have given more precise knowledge still ?—Yes. 4072. And you think they are leading to still further precise knowledge ?—Yes, they sre leading to a more precise knowledge of the exact point of the action of digitalis on the heart. 4675. We cannot foresee what other witnesses” opinions may be, and there may be some who contest that. Perhaps you would explain, if you can explain, what the precise further discoveries are ?—It is a little difficult to put it into words. 4674. I do not mean exactly, but the direction of them. You have told us that they discovered that digitalis acted on the heart muscle ?—Yes. 4675. Does that remain true?—That remains true, but it is further defined. The idea arose about that time, partly from Schmiedeberg’s work, that the con- traction of the heart was prolonged under digitalis, whereas this is not true in mammals, at any rate; the contraction of the heart is not prolonged, but is strengthened only, it is not actually longer than before. And then the further point came out that digitalis acted in two ways. It acted first on the heart muscle and then indirectly through the controlling nerve of the heart, the pneumo-gastric. And those two points are of considerable importance, because it is found, for example, in patients, that sometimes the heart is not slowed under digitalis at all owing to this controlling nerve not acting, while in ordinary persons the heart is distinctly slowed through the control nerve being active. Now, one point is that this slowing of the heart is so common that physicians are apt to regard it as an indication of the action of digitalis; and when the slowing is absent, they think the digitalis is not acting and give more digitalis, give larger doses. But in certain cases this slowing is absent, or is quite slight in amount, and yet the ful] action on the heart muscle is taking place ;.so that there may arise a danger from larger doses than are actually being given. Later work showed that one must not depend too much upon the slowing of the heart which had been supposed to be quite a gure sign of the action of digitalis. 4676. Would you say that that further discovery, that digitalis acted through the nerve in the way you _have described, was a thing not merely to satisfy what you may call a physiological curiosity on the part of the operator, but was something practically useful to a doctor in practice ’/—Yes, I think so, simply in show- ing the doctor that this secondary action upon the ‘muscle direct might be present when the slowing was absent. there is no slowing, or very slight slowing, and yet the direct muscular action is going on. 349. : careful in applying more digitalis, 4678. (Sir William Church.) Was the action of digi- talis on the walls of the vessels known before ?—It was known,; at least, it was suspected from the time of Traube and Brunton. 4679. But not before ?—No. 4680. You might have mentioned that perhaps as another point which was discovered of the action of digitalis ?’—I intended to bring that out when I said that their essential discovery was increase of blood pressure through a new agency, which had been missed entirely before, namely, the action on the vessels as well as on the heart. All the work since Traube and Brunton has been to show that digitalis is a much more complicated problem than was supposed before their time, that it affects a much larger number of systems. 4681. (Chairman.) Were these other experiments which led to the discovery of the action on the vessels 4582. And are experiments directed to increasing that knowledge now going on from time to time in regard to digitalis?—Yes, there is a constant series of new questions coming up. As one question seems to. be decided, it is found that it only suggests a furtker- one. The knowledge of digitalis which has been eb- tained in the Jast quarter of a century is much greater time. been elucidating its action further in different direc- tions. 4683. Have those experiments been experiments of the same description so far as regards the operation as those you described before ?—Of recent years much more work has been done on mammals under digitalis by exposing the heart. That is the essential change that has come. The heart is exposed instead of taking the indirect method of examining through the vessels —the heart itself has been exposed, and its movements have been observed, and have been recorded. 4684. That, I presume, is an operation that is done under anesthetics P—Yes, It cannot recover from an operation like that. 4686. Then I presume it is killed in the usual way when the operation is over ?—It is killed at the end of the experiment, certainly. In those experiments where the heart is exposed, of course the respiration hag to be carried on artificially, and if the animal does not. die of a large dose of digitalis, as is ordinarily the case, it dies at once when the respiration apparatus is stopped, 4687. Then those are cases in which the ordinary rule would apply, that anesthetics would be adminis- tered, and the animal would not be allowed to recover consciousness P—Yes, eens And they would not require any certificate P— 0. 4689. You have given us in digitalis the case of the of a drug in use. Now I think you are going to tell us of examples in which experiments have guided you in knowing whether a particular drug or medicine . should be accepted for use at ali?—Yes. Another result ; of experimental inquiry is that the physician demands. more certain evidence of curative action before accept- ing 4 drug. For many years lead had been used to arrest hemorrhage from the lungs, the lead being given by the stomach generally in the form of pills. Its efficacy was unquestioned, apparently, by physicians. is only absorbed in small quantities, and very slowly. This, of course, does not imply that it is useless in bleeding of the lungs, but it removed the basis of the underlying theory on which it had been used, and aroused the clinicians to more careful analysis of the cases in which they had previously used it, the result being that it was found that not the lead but the opium with which it had been administered was the efficient principle in arresting the haemorrhage. So that experi- mental inquiry in this instance, as in many others, is D eee](https://iiif.wellcomecollection.org/image/b3218217x_0025.jp2/full/800%2C/0/default.jpg)
