but in a state of complete solution. Of all these component parts, the most important is an animal product named _urea_, which exists in about the proportion of one in thirty to the water containing it, while the other materials taken collectively, water excepted, yield only about double the quantity of the urea: hence, when the urine is disordered, its specific gravity[17] is increased or diminished, as the case may be; according to the abundance of the urea, and the various proportions of the saline ingredients of the urine, so is the urine thick, thin, acid, or alkaline, pale, or what is called high colored. The various conditions of the urine are ascertained by producing chymically certain decompositions, or by suffering the urine to effect its own changes, which, on being suffered to “stand,” sooner or later it will. Healthy urine is perfectly transparent and of a light amber color; it yields an odor when warm resembling violets. Its taste (for pathologists trust not only to sight and smell) is saltish and offensive. As the urine cools, it throws up what may be said to be a “urinous smell.” As decomposition proceeds, the urine becomes cloudy, thick, with shining floating patches on the surface; and lastly, a thick deposite coats the bottom and sides of the vessel, the whole giving forth at the same time a fetid ammoniacal exhalation, as is perceived on entering public urinals. The rapidity with which these several mutations occur, affords some criterion of the healthy or disordered state of the excretion we are talking about, and hence the usefulness of examining especially the urine of persons laboring under any disorder of the urinary system and functions connected therewith. A patient will complain, for instance, of irritable bladder. The symptoms of that complaint, as far as pain and frequent desire to micturate exist, very closely resemble those affections known by the name of “Diabetes,” but which is distinguished from the bladder affection in question by the quantity and character of the urine. I purpose herein to enumerate, in as familiar a manner as is possible, the various disordered states of the urine which my experience has rendered me familiar with, and to present the same as heretofore, in the form of cases that have fallen under my notice. Now, the urinary disorders that I purpose to collect a description of, and exemplify, may be thus enumerated:— First, where too great a quantity of urine is voided. Secondly, where too little is discharged; and also, where suppression of it entirely occurs. Thirdly, those states where the urine deposites a sediment, of which two kinds are mostly prevalent, namely, the Lithates or Acid, and the Earthy or Alkaline. Fourthly, a brief exposition of the many but less frequent morbid changes of the urine, in which certain salts and substances, not existing in healthy urine, are precipitated or held in solution.