Should the horse be seized where no medicine can be obtained, then extract blood from free openings till fainting takes place. Several small depletions are very weakening, and a large quantity of the vital fluid drawn at different times is far less likely to overcome the disease than one full venesection. Open both jugulars: allow the blood to flow from both veins till the water rushes forth or the animal falls, when, insensibility being produced, everything like spasm disappears, and the bladder will mechanically empty itself. Should not such a relief ensue, the greased arm may be inserted up the rectum, and gentle pressure made upon the gorged viscus. Advantage is thus taken of the animal's insensibility to adopt a mode of relief which we dare not hazard while consciousness is retained. CALCULI. Stones within the urinary apparatus are designated by various names, that are derived from the situations in which they are found. Thus =renal calculus= represents a stone which has been discovered within the pelvis of the kidney. =Uretal calculus= implies a stone found within the tubes leading from the kidneys to the bladder; but calculi of this kind are as yet unknown in the horse. =Cystic calculus= signifies a stone which resides in the cavity of the bladder. =Urethral calculus= denotes a stone which was detected within the passage leading from the bladder. Of these the cystic are altogether the largest, and the renal, at a considerable distance, rank as the next in magnitude. All consist of carbonate of lime or of common chalk, held firmly together by the secretion of the mucous membrane. The symptoms which characterize renal calculus are not well marked. The urine may become purulent, thick, opaque, gritty or bloody. Exertion may provoke extreme anguish, resembling a severe fit of colic; but the attack is distinguished from genuine gripes by the back, during the pain, being always roached. However, the most decided symptom is of a negative nature; being the absence of stone in the bladder to account for the diseased urine. The inference is, moreover, strengthened if, when the hand within the rectum is carried upward, pain and alarm are elicited; or if pressure made upon the loins causes the animal to shrink. Cystic calculus is denoted, as is the previous kind of stone, by certain conditions of the urine. Added to these general signs, the water, when flowing forth, will often be suddenly stopped, and every emission is followed by violent straining. Abdominal pains also are present; but the back is rather hollowed than roached. The point of the penis is, in particular instances, constantly exposed; and the horse, when going down hill, sometimes pulls up short, either to recover from torture or to relieve the bladder. [Illustration: A CERTAIN METHOD OF ASCERTAINING IF THERE BE CALCULUS IN THE BLADDER.]