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
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.
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![poisoned motor nerves of the fore limbs and trunk, but found vent through the unpoisoned motor nerves of the hind limbs. In order to bring out these results well, the dose of poison must not be more than sufficient to poison frog lay bare the sciatic nerve on one side, . . • . • place a ligature under it, near where it divides into two branches, and tie the ligature tightly round the leg above the knee. The circulation of the lower right leg will thus be completely arrested; but, inasmuch as the nerve is not included in the ligature, there will be complete nervous connection betweeen the right lower leg and the rest of the body. Poison wdth curare .... In a fresh strong frog dissect out a gastrocnemius (or any other single muscle), dividing both insertion and origin, and ligaturing its blood vessels, thus leaving it connected with the rest of the body by its nerve only. Poison the frog with curare. the organs of consciousness are intact, and the ordinary tokens of sensation are used to determine whether the impulses caused by stimulation of the peripheral termi- nations reach the conscious central nervous system or not. But the facts may also be readily shown in the absence of the brain, when reflex action is taken as a proof of a centripetal impulse having reached the spinal cord. In the former case, the frog should be placed under chloroform during the laying bare of the roots. In the latter the medulla should be previously divided in the neck. The frog being placed on its belly, make an incision in the middle line of the back, from the upper end of coccyx to the level of the fore limbs. Having hooked back the flaps of skin, carry the median incision down to the spines of the vertebrae and dissect away the longitudinal muscles on either side, so as to lay bare the bony arches, and then hook back the muscles on either side, or cut them away altogether. With a small but strong blunt pointed pair of scissors cut through, on either side, the arch of the last (eighth) vertebra (be careful not to thrust the scissors in too deep), and remove the piece so loosened. Proceed then to the next arch above and so remove, three arches. The roots of the nerves will be seen lying in the spinal canal. Snip away the remains of the arches, on each side, until the last three (or four) roots are quite clear, being very careful not to touch the nerves with the scissors. The frog being completely at rest, draw the ligature tight, observing the frog all the while. If the animal be in good condition, some movements will be visible in some parts of the body as evidence either of sensibility or reflex action. Now cut the nerve between the ligature and the cord; some movement mil probably be again witnessed. Lift the peripheral stump of the nerve carefully up by means of the ligature, and sUp it upon the curved shielded electrodes which may he held in the hand, or, better, fixed on a movable stand. To prevent any escape of the current, slip a fragment of india-rubber sheeting beneath the nerve and electrodes, so as to isolate these from the cord and from the rest of the nerves. Pass a moderately strong interrupted current through the electrodes. If there be no escape of the current the animal will not move in the slightest. Repeat'the observation with the nerve root next above (the 8th), with this difference; place the ligature as near as possible to the walls of the spinal canal; divide the nerve between the ligature and the waU, and place the central instead of the peripheral stump on the electrodes. Ligature and section as before produce movements. A very moderate current applied to the central stump wiU produce very considerable movements in various parts of the body; i.e. signs of sensation or reflex action, as the case may be. Ligature or section of the posterior roots of spinal nerves produces movements in various parts of the body. Stimu- lation of the peripheral stump produces no movement whatever; stimulation of the central stump produces con- siderable movements. These movements, be they simple reflex aetions or more complicated voluntary movements set going by conscious sensations, are evidences of centripetal sensor impulses, excited in the posterior sensory roots. Page 402.—In a fresh strong frog lay bare the roots of the spinal nerves and divide the posterior roots of the 7th, 8th, 9th, and 10th nerves on the right side and the corresponding anterior roots on the left side. The left leg will remain motionless, being simply dragged along by the rest of the body, but never moving of itself. (If the brain has been previously destroyed or separated from the spinal cord, the right leg will be drawn up as usual, but not the left leg.) witnessed in the frog. It can only be shown in the higher animals, the cat or dog being best adapted for the purpose. The method adopted is very similar to the above, the arches of one or two vertebrae being carefully sawn through or cut very carefully freed from the connective tissue surrounding them. If the animal he strong and have thoroughly recovered from the chloroform and from the operation, irritation of the peripheral stump of the anterior root causes not only contractions in the muscles supplied by the nerve, but also movements in other parts of the body indicative of pain or sensations. On dividing the mixed trunk at some little distance from the junction of the roots, the con- tractions of the muscles supplied by the nerve cease, but the general signs of pain or of sensation still remain. Page 411.—In a frog with divided medulla, ligature the hind limbs, leaving the nerves free as directed in chap. 31 for curare, and afterwards inject a small dose of strychnia. and sympathetic fibres of the submaxillary gland in the dog. The animal was placed under the influence of the chloroform, when no less than 15 different dissections were made to obtain a fistulous opening. After which the author says, p. 473, “ The animal must previously be “ allowed to recover from chloroform, or no increase [of “ saliva] will be observed.” Page 474.—After division of both nerves the secretion of the submaxillary gland, which in the normal state only goes on when the gland is directly or reflexly excited, becomes constant and abundant. This effect does not occur until some time after section, and may last for days or weeks. A similar condition of the gland is produced by the introduction of curare into the blood which is supplied to the gland by its arteries. Page 477.—Give the dog a hearty meal, so as to distend its stomach completely, and make it lie close against the intestinal walls. Anaesthetise the animal by chloroform, taking care that the vapour is mixed with a sufficient proportion of air. Lay it on its back on the table, shave off the hair from the epigastric and hypochondriac regions, and remove the hairs carefully by a sponge, so as to prevent the risk of their getting into the peritoneal cavity. Make a vertical incision, about an inch and a half to one side of the linea alba, preferably the left, and parallel to it, extending downwards from the lower edge of the costal cartilages to a distance somewhat less than the diameter of the flange of the cannula. Divide the muscles parallel to the course of their fibres. Tie every bleeding point before opening the peritoneum, so that no blood shall get into its cavity. Open the peritoneum on a director. Lay hold of the stomach with a pair of artery forceps at a point where there are not many vessels, and draw it forwards. Pass two threads with a curved needle into the gastric walls, at a distance from each other about equal to the diameter of the tube of the cannula, and bring them out again at a similar distance from the points where they were introduced. Make an incision into the gastric walls, between the two threads, rather shorter than the diameter of the tube of the cannula. Put a pair of forceps, with the blades together, into the incision, and then dilate it by separating the blades till it is large enough to allow the cannula to be introduced. Push the cannula into the stomach up to its outer plate. Tie the stomach to it by the' threads, and then pass their ends through the edges of the wound in the abdominal wall in such a way as to fasten the stomach to it, and at the same time to keep the cut edges in appo- sition. No other suture is required. Leave the cannula uncorked for at least half an hour after the operation is finished, for when the dog recovers from the chloroform it will vomit, and if the cannula be corked the fluid contents of the stomach are apt to be forced passed the side of the cannula into the abdominal cavity. Feed the dog on milk for one or two days, and if the operation be performed in v/inter, keep it in a place warmed night and day. The day after the operation the edges of the wound will be much swollen, hut the swelling will subside in a day or two. After the wound has begun to heal, the cicatrix may thicken, and the outer plate of the cannula begin to press too much on the skin, so that it ulcerates. If this should occur, the cannula must be lengthened by screwing the two flanges further apart. The cannula maybe closed by an india-rubber stopper, or by a cork. If the dog tears out the cork with his teeth, soak it in decoction of colocynth, or put a little phosphoric acid on its outer end. In order to collect the juice, let the animal fast for several hours, so that its stomach may be quite empty, but not for more than a day, as the mucus membrane would become covered with a thick coating of mucus. Let an assistant pat the dog and keep him quiet, with](https://iiif.wellcomecollection.org/image/b21302893_0415.jp2/full/800%2C/0/default.jpg)
