Soap and lime-water not only relieve the painful symptoms occasioned by the stone, by wearing off its sharp points, and rougher parts, which used to irritate the tender membrane, which lines the bladder; but, when this membrane has been wounded or lacerated by the stone, there is nothing, that will heal it more speedily than lime-water; which the ingenious Dr. Langrish has found to be remarkable also for its effects in curing the bladders of dogs, after being fretted with soap-lees[135]. The power of soap and lime-water to alleviate the painful symptoms attending the stone is so great, that, as far as I remember, I have only met with one patient, who did not find himself considerably relieved by them. But it is to be observed, that this patient neither took them in full quantity, nor persisted in their use for a long enough time: and, when he was afterwards cut, the stone taken out of his bladder was almost as thick set with sharp prickles, as the back of an hedgehog: so that, in this case, no remarkable ease could be procured to the patient by the medicines, until they had quite dissolved these sharp points, and rendered the surface of the stone smooth and equal; which was not to be done but after a very long time, especially as the stone was of a pretty hard texture. It may be proper to take notice, that when, along with the stone, there is any ulceration in the bladder, soap does mischief, and lime-water often fails of giving any considerable relief. However, even in this case it is perhaps one of the best remedies we know. 5. Soap and lime-water, taken in large quantities, and persisted in for many years together, appear to be innocent, and no way injurious to health. Lord Walpole, who used these medicines for upwards of eight years, was not only relieved of the painful symptoms of the stone, but had his health improved by them in other respects[136]. His appetite, healthful look, and a degree of spirits uncommon at his age, continued till the end of 1756, when his last illness begin to attack him. And as his health did not appear to be any way injured by these medicines, so, where his body was opened after death, his kidneys and ureters were observed to be quite sound and natural, as was likewise his bladder; only its coats appeared a little thicker than usual, owing probably to the long-continued friction of the stones upon it. Neither the kidneys, ureters, nor bladder, were loaded or crusted with any calcarious matter; an effect most unjustly ascribed to soap and lime-water, since in the urinary passages, to which the air has no access, they cannot deposite their calcarious part[137]; and since the white stuff observable in the urine of such patients, as take these medicines in large quantities, is only the usual sediment of the urine changed in its nature and colour, with, perhaps, some of the dissolved particles of the stone[138].