"Alkalescent urine, and phosphatic urinary calculi"

London Medical Gazette
(7 November 1846)Presentation before the Westminster Medical Society.

The first meeting of the WMS of the 1846-47 session was held in the rooms of the Ethnological Society, 27 Sackville Street. "The attendance of members was numerous, and the very greatly increased comfort and accommodation offered at the new place of meeting gave great satisfaction to the members present." Snow's paper, and subsequent discussion, occupied the entire meeting.

"He said, that when the bladder remained constantly full, as in paralysis of the organ, the urine was known to become alkalescent from decomposition. He had met with a case of incontinence of urine four years ago, in which the whole of the urine became highly ammoniacal, from about half an ounce remaining constantly in the bladder; and he afterwards performed experiments to ascertain if a still smaller quantity remained unvoided, might not have the same effect. Newly voided urine was kept at the temperature of 100 degrees, dropping from one vessel into another about the rate at which it enters the bladder; the glass vessels were emptied every six or eight hours; about thirty drops, however, always being left in the lower one, whilst the upper one, after being washed out, was filled again with newly voided urine. It was found that the urine in the lower vessel became strongly alkalescent, and remained so as long as the experiment was continued, whilst in the upper one it was always fresh. He considered that these experiments would assist to explain a number of circumstances connected with phosphatic deposits and calculi, and would suggest an important improvement in the treatment of a numerous class of cases. With a calculus, or any foreign body in the bladder, it was impossible that it could be completely emptied of urine, and even the urine imprisoned in the pores of a calculus would be enough to cause decomposition in many cases; accordingly it was found, that if a foreign body found access into the bladder, it became nearly always covered with phosphates, and every kind of vesical calculus was liable to become encrusted with them; whilst they, on the other hand, scarcely ever became covered by any other deposit. It was believed by the best authorities, that foreign bodies caused chronic inflammation of the mucous membrane of the bladder, when it poured out alkaline mucus which decomposed the urine. This might be true in some instances; but a pea, or a bit of fibrine, indeed the most inoffensive substance, was certain to become covered with the earthy phosphates. When the urine became ammoniacal from the decomposition of the urea, the ammonia, besides throwing down the triple phosphate from the urine itself, produced great irritation of the mucous membrane of the bladder, and caused it to pour out quantities of phosphate of lime mixed with mucus.

Patients suffering from injuries and diseases of the spine were well known to be subject to alkalescent urine, and, indeed, often died of diseases of the bladder and kidneys; he enumerated the various explanations which have been given of this, and offered the following: that the muscular coat of the bladder was, like the other voluntary muscles, subject to partial as well [852/853] as complete loss of power; and that when weakened by an affection of the spine, it might be able to void the urine, but not to contract in that vigorous and perfect manner necessary to expel the last drop of urine; more or less would be left behind each time, and this would cause decomposition, which, by its continuance, would irritate and cause disease of the bladder; and that the decomposition, in course of time, might be propagated up the ureters, and cause phosphatic deposits in the pelvis of the kidney. He thought that the debility of extreme old age, and states of great nervous irritability and depression, caused alkalescent urine, generally, by withholding the power from the bladder to empty itself completely; and that the phosphatic diathesis, in the proper sens of the term,-viz., the secretion of the phosphates in excess by the kidneys, was extremely rare.

He recommended injecting the bladder, in these cases, every day, or every other day, with warm water, to wash it well out, and thus preserve its mucous membrane and the urine form disease, until time and other remedies might fully restore the impaired function of the muscular coat of the bladder, or remove whatever prevented its being duly emptied. He considered this practice would greatly improve our treatment of stone in the bladder, by enabling us to keep the urine in a healthy condition; healthy urine, according to Dr. Prout, being the best solvent of all kinds of calculi we could hope to possess.

The case of incontinence of urine alluded to at the commencement, occurred in a female after a very tedious labour. He (Dr. Snow) was made aware of the complaint between two and three weeks after the labour, as she then had ceased to pass urine in the usual manner; the urine was highly ammoniacal, and quantities of phosphate of lime mixed with mucus, like soft mortar, came away with it; the genital organs were excoriated. There was an incrustation of phosphate of lime around the or [sic] uteri and upper part of the vagina, he considered, from the ammoniacal urine irritating the mucous membrane. There was no fistulous opening; the incontinence of urine appeared to depend on a morbid adhesion of the cervix uteri to the anterior wall of the vagina, and the patient gradually recovered from it in the course of a few months. On being called to the patient, and passing a catheter, he found that about half an ounce of urine was always present. On washing the bladder well out, the urine which flowed the rest of the day was neutral to test-paper, although, just before, the excretion had been so much decomposed. By injecting the bladder about every alternate day, for several weeks, the urine was prevented from ever getting into the same alkalescent state. Other treatment was also used.

Mr. Hancock considered that Dr. Snow had not sufficiently distinguished between the triple phosphates, which he (Mr. Hancock) considered were secreted by the kidneys, and phosphate of lime, which was secreted by the mucous membrane of the bladder when irritated by a calculus, or any foreign body. A uric acid, or other calculus, did not become covered with triple phosphate unless alkalies were given as a remedy, which rendered the urine alkaline; but it might be coated with phosphate of lime, from its irritating the bladder. He was of opinion that the alkaline urine in injuries of the spine depended on the altered secretion of the kidney, and that it ceased as the patient regained his strength. He had had a patient in the hospital with an injury of the spine, in whom the urine was alkaline; he partly recovered, and it became acid; on his relapsing, it became alkaline again, and so continued till his death, and triple phosphate was found in the pelvis of his kidneys: that patient's bladder was injected, but it did not render his urine acid.

Dr. Frederick Bird thought that, in the case related, there had been a fistulous opening between the bladder and vagina, and that it had become cured by the morbid adhesion of the cervix uteri.

Dr. Sayer mentioned the case of a lady who died of mollities ossium, becoming deplorably deformed; her illness commenced after a confinement, three years before her death, and was accompanied by alkalescent urine, and a copious deposition of phosphates.

Dr. Snow thought that the irritation of alkalescent urine in the bladder might cause such a secretion of phosphate of lime as should lead to softening of the bones; he fancied, that the pelvis of the patient whose case he had related, had altered its form, on account of the phosphate of lime secreted before the treatment began.

Snow sent his paper, perhaps with some revisions, to the editor of LMG on 9 November, two days after delivering his remarks. It was published shortly thereafter as:

"Some remarks on alkalescent urine and phosphatic calculi," by John Snow, M.D., Lecturer on forensic medicine at the medical school, Aldersgate Street. LMG 38 (20 November 1846): 877-81. Snow sent it as a letter, concluding with "54 Frith Street, Soho Square. Nov. 9, 1846."