122 REPORT— 1869. 



On the Solvent Treatment of Uric-Acid Calculus, and the Quantitative Determi- 

 nation of Uric Acid in Urine. By the Rev. W. V. Haecoukt, F.R.S., Sfc. 



The author of this paper having been apprized of the presence of a calculus in 

 the bladder of considerable size*, and consisting in all probability of uric acid, re- 

 solved upon giving a trial to the solvent alkaline treatment as proposed by l)r. 

 Roberts, Physician to the Manchester Roj'al Intirmary, of which the lirst notice 

 ■will be found in the Eeport of the British Association for 1861, and of which he 

 has given a full account in his ' Treatise on Urinary and Uenal Diseases.' 



In one of the leading experiments made by Dr. Roberts, he passed the urine of 

 a patient who was taking citrate of potash at the rate of 40 grains in 5 ounces of 

 ■water every two hours, over a fragment of uric calculus, and by this process re- 

 duced it in twelve hours from 180-5 to 174 grains, or at the rate, in twenty- four hours, 

 of 13 grains. If the action within the bladder resembles that without it, though 

 the action on an entire calcidus could not be expected to equal that on a fragmen- 

 tary piece, yet there was reason to expect a difterence between the quantity of 

 uric acid normally excreted and the excretions under the effect of the alkaline 

 treatment, determinable by chemical analysis. With this view the author insti- 

 tuted a series of experiments in his own laboratory, which, though they did not 

 fully realize his expectations, throw some light on this important subject. The 

 method first employed of precipitating the uric acid was that in ordinary use by 

 hydrochloric acid. The first seven determinations, from the 20t]i of August, 

 1868, to the 26th inclusive, were made each day on the urine of the preceding 

 twenty-four hours, in a neutral or slightly alkaline state, brought to that state by 

 doses of from 120 to 105 grains of citrate of potash. The quantities of uric acid 

 obtained varied from ll'08to 8'43 grains. In the subsequent daily determinations, 

 down to the 5th of September, acid reactions were interpolated, due to the use of 

 smaller alkaline doses, which lowered proportionably the amount of uric acid ob- 

 tained ; and when no alkali had been taken for two daj^s, and the urine was in 

 consequence strongly acid, the quantity of uric acid found was only 2-35 grains. 



From this time commenced a course of large quantities of citrate of potash, 

 amounting, during fourteen days, to 315 grains in twenty-four hours, taken in a 

 state of eft'ervescence, in do!;es of 45 grains, dissolved in 3 fluid-ounces of waterf . 

 For ten of these days hydrochloric acid was used to precipitate the lu'ic acid ; 

 and the determination of this gave from 11 -90 to 6-00 grains. The preference, 

 however, assigned by Dr. Thudichum, in his able and well-known treatise on the 

 'Pathology of the Urine,' to nitric over hytirochloric acid, as having given him 

 better results, led the author subsequently to employ his method. Tlie quan- 

 tity of citrate of potash taken in twenty-four hours was then raised to 350 grains 

 for four consecutive days. On the first of tliese days the uric acid found was 1'54 

 grain, on the second 1'23 grain. These results were so extraordinary that, for 

 the purpose of corroborating them, or disco^•ering any error. Dr. Thudichum was 

 requested to imdertake an analysis of a portion of the urine of tlie latter day. Ac- 

 cording to his analysis the uric acid amounted to no more than 0'775 grain. 



This result led to one of two conclusions; either independently of any question 

 of the solution of the calculus the presence of the lu-ic acid in the bladder had 

 been almost entirely prevented by the alkaline treatment, or the process for ob- 

 taining it was altogether unreliable. The latter alternative appearing the most 

 probable, more attention was given to the method of determination. One half of 

 a urine which had yielded 8-42 grains with hydrochloric acid, was treated with 

 }r> per cent, nitric acid and kept at the temperature of 90° F., the alkalinity and 

 dilution ha^^ng been brought to a standard corresponding with the urine analyzed 

 by Dr. Thudichum. The uric acid thus obtained weighed 2-07 grains, showing a 

 loss by this method of 6-35 grains. The alkalinity was now determined for every 



* The size of the calculus, as determined by Mr. Spencer Wells, and confirmed by Sir 

 H. Thompson, was 1-5 inch in one of its diameters. 



t The tides of acidity and alkalinity in urine, consequent on digestion, which occur at 

 different periods of the day and night, deserve attention in the distribution of alkaline 

 doses, especially when the quantity taken is small enough to leave an aj)prehension of 

 uric acid being deposited in the bladder. 



