The Pedestrian's Record

104 the pedestrian's record. congestion cannot take place unless the nerves be first involved in diseased action, and the experiments which led to the elucidation of the true nature of con­ gestion. Sir Joseph Lister, whose lectures on pathological anatomy and practical surgery we had the good fortune to attend at Edinburgh, performedthe follow­ ing experiments :—He applied,previous to slaughter, two bandages firmly around and about the knee- joints of a sheep. The animal having been killed, both legs were amputated just above the bandages, when the skin was carefully dissected up from the leg, and taken off the right side, viz.. A, in order to expose the metacarpal or leg vein. This being done, the external coat of the vein was painted with liquor ammoniae, and the skin was again replaced ; and this leg, together with B (the one taken from the left side), was laid aside until the following day. After a lapse of twenty-four hours the legs were reproduced, and B was now placed upon the table, and the leg- vein was exposed, which, be it remembered, had undergone no treatment withammonia or otherwise. The vein was now opened, and from it the blood in a perfect state of fluidity was poured into a plate. The coats of the blood-vessel whence this fluid was obtained had not been killed or devitalized by the application of caustics, blisters, or any other com­ pound calculated to destroy the integrity of or para­ lyze tissue ; but with the leg A the case was different. This had been dressed with ammonia; by it the coats