Report of the Royal Commission on the practice of subjecting live animals to experiments for scientific purposes : with minutes of evidence and appendix.

  • Great Britain. Royal Commission on Vivisection
Date:
1876
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Licence: Public Domain Mark

Credit: Report of the Royal Commission on the practice of subjecting live animals to experiments for scientific purposes : with minutes of evidence and appendix. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    396/450 (page 366)
    App. IV. stopped in 7 minutes 10 seconds ; and, consequently, that the interval between the last respiratory effort and the cessation of the heart’s action was 3 minutes 45 seconds. [Then follows a series of experiments in which the plug was withdrawn at different intervals, and the dogs delivered from the pains of death, and were subsequently operated on again. The committee say ;—] These results lead to the conclusion, 1st, that a dog may be deprived of air during a period of 3 minutes 50 seconds, and afterwards recover without the application of artificial means ; and 2ndly, that a dog is not likely to recover if left to itself after having been deprived of air during a period of 4 minutes 10 seconds. For some time after the occlusion of the tube in the trachea the force of the respiratory efforts was so remarka,ble that it was determined to adopt some means of measuring it The following were the results :— Experiment 15.—A medium-sized dog was treated in the above way. The respiratory efforts commenced at •2 minutes 5 seconds. As apnoea advanced they became more powerful, and from 3 minutes 20 seconds and onwards they were very violent till 4 minutes 45 seconds, when they ceased. The needle showed the heart to be moving up to 8 minutes. This dog drew the mercury up the tube, by its violent inspiratory efforts, a height of four inches, and that height was attained in almost the last attempts at respiration, -4 minutes 45 seconds after the estalilishment of the apnoea. On examination the lungs were found to be congested, but there were no ecchymosed spots or blood in the tubes. [Then follow similar experiments which produced similar congestion of the lungs.] In the following experiments the great force of the inspiratory efforts was demonstrated in another way. Experiment 18.—A guinea-pig was held so that its nose was immersed in mercury, the animal being upside down, and the nose inserted sufficiently deep in the merely to prevent the jiossibility of getting any air. The respiratory efforts commenced at 35 seconds, and ceased at I minute 37 seconds. On examining the lungs they were found full of globules of mercury, which had thus been drawn up by this weak animal a distance of an inch or two, and that in spite of gravitation. .... Experiment 19.—A terrier was deprived of air by plunging its head into liquid plaster of Paris, the object being, to see, through the whiteness of the plaster, whether any of the fluid obtained access to the lungs. Respiratory efforts commenced at 1 minute 35 seconds, and ceased at 4 minutes, the heart beating till 5 minutes. On examining the lungs the white plaster was found throughout the bronchial tubes. From these preliminary experiments on the effects pro- duced by simply depriving an animal of air, the Committee passed on to the consideration of drowning. The first point to be ascertained was, “for what period can an “ animal be submerged and yet recover without the aid “ of artificial means ? ” Experiment 20.—A medium-sized dog was fastened to a board and submerged in a large bath. It was removed in 4 minutes, but although the heart went on acting for 44 minutes longer, it neither gasped nor moved. [Two similar experiments follow.] It having been thus ascertained that 4 minutes drowning kills, it was determined gradually to shorten the time, in order to find out what was the limit of time at which immersion proved fatal. Experiment 23.—A dog was bound as before to the board and immersed for 3 minutes 15 seconds. On being taken out of the water no respiratory efforts were made; the dog was dead. Bloody froth escaped from its mouth, and its lungs were full of the same material. Experiment 24.—The same as above, but the dog’s head was kept under water 2 minutes only. The dog gasped once or twice, and then died. Lungs full of blood and watery froth.” [Five other dogs were then submerged, and removed at graduated intervals of time.] Having seen that a dog lives after being submerged 1 minute, and dies after being submerged 1 minute 30 seconds, another experiment was performed. Experiment 30.—A large dog was submerged 1 minute 15 seconds. On being removed, it perfectly and almost immediately recovered. Thus, then, the remarkable fact appeared that, whereas in simple apnoea recovery may be possible after the depri- vation of air for 3 minutes 50 seconds (Experiment 13), and subsequent experiments showed that a dog simply deprived of air almost certainly recovered after 4 minutes, 14 minutes immersion in water suffices to destroy life; Now, to what is this striking difference due? With reference to this question the following experiments were performed :— It was resolved in the first jilace to eliminate the element of exhaustion produced by struggling; it was thought that possibly the violent struggles of the animal to gain breath when its limbs were confined might exhaust it and hasten the catastrophe. Experiment 31.—A cat was placed in a cage, and the cage plunged under water. The animal’s limbs were at perfect liberty, and there were no violent struggles. After 2 minutes the cage with the cat in it was taken out, and the cat was dead. Experiment 32.—A dog was treated in the same way, but the cage was kejit submerged in the water only 14 minutes. The dog died. There had been no struggle. Thus it was seen that struggling had nothing to do with the early fatal result, as it happened equally soon when there were no struggles. It was next determined to eliminate the element of cold, and for that purpose the following five experiments were performed, in which cold was applied to no part of the surface except the animal’s head. [All the dogs died.] Still further to clear up this question it was determined to place two dogs under precisely similar circumstances, with the single exception that in the one case the free access of water to the lungs should be permitted, and in the other case prevented. The following were the experiments Experiment 38.—Two dogs of the same size were fastened to the same plank and submerged at the same moment, but one of them had previously had its wind- pipe plugged in the usual way and the other had not. At 2 minutes they were taken out together ; the one that had. been plugged at once recovered, the other died.” [This was repeated, and the Committee add]— These experiments satisfactorily show that the difference between apnoea produced by plugging and that by drowning is not due to submersion, to depression of temperature, or to struggles.' ...... The fact that animals do not recover after so short a period of immersion is mainly due to the entrance of water. [Three other experiments were tried with windpipes plugged, after which chloroform was used.] Experiment 43.—A medium sized dog was rendered insensible by chloroform and drowned. It was kept in in the water for 24 minutes. Its respiratory efforts were by no means violent, and were in this respect in strong contrast with those of the unchloroformed dogs. [Two other experiments of a similar kind followed, which proved]— That by simply depriving the animal of the power of making violent respiratory efforts the period during which submersion may be continued, and yet recovery follow, is at once prolonged. The value and conclusiveness of these chloroform experiments, as showing the essential connexion between the early fatal result in drowned animals and the violent inspiratory efforts that fill the lungs with water, need not be pointed out. .... Various means of resuscitation were employed in many of the experiments performed by the Committee, and with variable results. [Then follow seven experiments, in all of which, save one, the animals died.] Experiment 51.—The same dog as had been previously used in Experiment 13 was again deprived of air, as before, and on the use of Dr. Marcet’s, instrument 1 minute after respiration had ceased it again recovered. [This poor dog, therefore, recovered from death twice. The Committee then say]— No definite conclusion concerning the relative value of the various methods of artificial respiration can be drawn from these experiments. For this subject the Committee would refer to the “ Report of the Experiments upon the Dead Human Body.” .