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XXII. Remarks on the Extractive Material of Urine, and on the Excretion of Sulphur 
and Phosphorus hy the Kidneys in an unoxidized state. By Edmund Ronalds, 
Ph.D., Giessen. Communicated hy Golding Bird, A.M . , M.D., F.R.S., fyc. 
Received April 25, — Read June 18, 1846. 
Some months back, at the instigation of Dr. Golding Bird, I undertook some 
experiments to ascertain whether, in cases of diseased and imperfect function of the 
lungs or liver, when the normal quantity of carbon could not be discharged from the 
system by those channels, the kidneys undertook an extra duty, and whether under 
such circumstances an excess of carbon could be shown in the urine above that 
usually secreted under healthy conditions. 
Should this question be answered in the affirmative, and should it be found that a 
larger amount, of carbon was excreted by the urine in persons affected with such 
diseases, a practical application might reasonably be made of the fact. For by 
stimulating the kidneys to still greater exertion, the amount of work required of the 
lungs or of the liver could be lessened, and thus a better chance offered them of 
being restored to a healthy state. 
The method proposed for solving this problem was, to precipitate the urine of dif- 
ferent patients suffering from diseases of the kinds mentioned, with basic acetate of 
lead, keeping it slightly alkaline by the addition of a few drops of ammonia, then to 
ascertain the amount of organic matter contained in the precipitate, and in particular 
the amount of carbon, and lastly to compare these quantities with those obtained 
in a similar manner from the urine of healthy individuals. 
In endeavouring to determine the amount of organic matter in the lead precipitate 
by burning, as likewise in determining the quantity of carbon by an elementary ana- 
lysis of the same precipitate with oxide of copper, results were obtained which did 
not agree, and many difficulties arose which it is not necessary to state now, but 
which rendered it absolutely necessary to separate by some means the organic matter 
from the oxide of lead before submitting it to analysis, and even that we might ob- 
tain accurately its quantity. Whilst employed in seeking an accurate mode of sepa- 
ration, Dr. Scherer’s paper appeared on the extractive matters of urine*, in which a 
successful mode of separation is described, and the question at issue answered. Dr. 
Scherer finds that the extractive or colouring matter of the urine contains a larger 
quantity of carbon and hydrogen when obtained from persons in whom the normal 
function of the lungs, of the liver or of the skin is deranged, than when taken from 
* Annalen der Chem. und Pharm. lvii. 180. 
