“Let me refer to what has been done by Dr. Roy in 1880, partly in the Physiological Laboratory at Cambridge, and partly in the Leipsic Philological Institute, the experiments being carried out on rabbits, cats, and dogs. The animal was placed under curare, artificial respiration was used, that is to say, a tube was pushed down the animal’s windpipe, and worked by an engine in regular puffs in order to keep the blood oxygenated. Then the back, skull, chest, and abdomen were opened. I don’t suppose these were always opened in one animal, as in many cases the animal would have died. No doubt sometimes part of the experiment took place on one, and sometimes on another. The various organs were dissected out. The principal nerves such as the sciatic nerve and so on, were tied in two places and cut. This lasted for many hours. It is stated the animal was under the influence of anæsthetics, but the use of curare is admitted. In the most scientific opinion, when curare is used, it neutralizes the use of the anæsthetic. I feel myself at a great disadvantage in treating of these matters as compared with the gentlemen beside me; but if I am making a mistake, I trust I may be corrected. In this instance, however, I believe I am right. Curare creates paralysis, it paralyses the muscles and prevents the animal resisting or showing the symptoms by which alone the existence of anæsthesia can be tested.”--_Mr. Reid’s Speech in House of Commons_, April 4th, 1883. “It was first sought to obtain information upon this subject by investigating the manner and extent to which the action of the heart is affected by obstruction of the renal arteries and the other large branches of the aorta; the facts obtained by taking this line of inquiry were not however of a kind fitted to throw light upon the problem which it was specially desired to solve. It soon became evident that an investigation of the manner in which the renal secretion and circulation are nominally regulated, and the relation which these bear to the regulating mechanism of the systemic circulation, would be best fitted to supply information of the kind required. The method employed, was to record graphically the changes in volume of one or both kidneys, while at the same time the changes in the blood-pressure in the aorta and the rapidity with which the urine was secreted were also recorded on the same revolving cylinder or, as continuous tracings, upon the paper of Ludwig’s kymograph. The method used for recording the changes in volume of the kidney is the same in principle as that of the plethysmograph. The kidney is enclosed in a rigid metal box, the arrangement being such that while the organ can freely expand or contract, and while the changes in volume are recorded by a lever writing with a light glass pen upon the kymograph paper, no obstruction is offered to the entrance and exit of blood by the renal vessels nor to the outflow of urine by the ureter. The kidney