" The following are the general characteris tics of the urine in inflammatory affections. It is darker than usual, and of a yellow, brown, or reddish-brown tint ; it has an acid reaction, and is generally of a high specific gravity. With respect to its most important consti tuents, the urea is either absolutely increased, or is at the ordinary physiological average, or may be a little below it ; the uric acid is always absolutely increased, and so are the extractive matters, especially the alcoholic extract. The salts are always absolutely di minished, especially the chloride of sodium. The sulphates, on the other hand, either ap proximate to the physiological average, or are not far below it.
" Assuming as the mean of numerous ana lyses, that the urea constitutes 39 per cent. of the solid residue of normal urine, I have found it as high as 46•8 in inflammatory af fections. (In abdominal typhus, with a quick small pulse, I have seen it as low as 22.) " The physiological average of uric acid may be placed at:1.5 per cent. of the solid residue ; in the phlogoses I have observed it amount to nearly 3 per cent., and Becquerel even found it rise as high as 5.9 per cent. The quan tity of extractive matter, &c., which in normal urine amounts to 23.5 per cent. of the solid residue, rises in inflammations to 43 per cent. The fixed salts, which in healthy urine con stitute about 25 per cent. of the solid residue, diminish here to 12 per cent. The sulphate of potash, which in healthy urine forms about 10 per cent. of the solid residue, I found to vary in inflammation between 7 and 9 per cent.
" The composition of the urine becomes changed if much blood is abstracted during the inflammation. It becomes clearer, speci fically lighter, and the amount of urea de creases absolutely and relatively.
"At the height of the inflammation, or (per haps it would be better to say) at the time when the fever puts on the synochal type most strongly, the urine is usually clear and deeply coloured ; it subsequently forms a sediment of a yellow or red colour, composed of uric acid and urates." I shall now proceed to describe the state of the urine as it is observed in different diseases.
Pericarditis.— A man aged 36. Acute pe ricarditis; pulse 108, full, and hard ; urine clear, deep red colour; specific gravity 1023.5; indications of albumen by heat. Analysis showed :— In the above case, after a large quantity of blood had been drawn, the urine changed as follows. Colour, that of health ; acid re action ; devoid of albumen ; specific gravity 1018. Its composition was now,— The first of these analyses is that of in flammatory urine. The second shows the effects of the copious bleedings in reducing the excretion nearer to the normal standard.
With respect to the presence of albumen in the urine in this and other inflammatory affections unconnected with disease of the kidneys, there is in my mind no doubt what ever that the opinion is founded in error. There is no institution in the world at which the question has been so thoroughly investi gated as at Guy's Hospital; and our daily ex perience still confirms the opinions arrived at by Dr. Bright in his first experiments. It will be observed that the test of heat (a most inefficient one in itself) is alone referred to in the above-described case ; and I have little doubt the precipitate produced was composed of phosphate of lime, a common source of fallacy which I pointed out some years ago in connection with this subject.*