364 



The third was a gentleman of 43, who had passed three small cal- 

 culi, and whose urine had for a short time been constantly turbid, 

 and occasionally deposited red sand. 



By the use of soda-water, these symptoms were diminished, but 

 returned in some degree even during the continued use of it ; and 

 his urine became also loaded with mucus. 



By taking twenty grains of magnesia every night, the uric acid 

 diminished in quantity, but did not disappear entirely, even by the 

 continued use of magnesia for three weeks in the same quantity. It 

 was then repeated ^every night and morning for a month, and suc- 

 ceeded in restoring the urine to a perfectly healthy state. Upon a 

 return of the disorder, he had recourse again to the magnesia, with 

 the same effect. 



The fourth patient was subject to gout, and occasionally voided 

 abundance of red sand, consisting of uric acid. He was subject to 

 heart-burn, and to other pains attendant upon weakness of stomach, 

 for which he had been in the habit of taking tincture of bark and 

 other spirituous medicines. He had also tried the use of alkalies, 

 but could not continue them on account of the unpleasant sensation 

 they occasioned in his stomach. 



Magnesia was accordingly given, at first three times a day, and 

 afterwards in a quantity of twenty grains twice every day ; and it 

 had the effect of lessening the disposition to form uric acid, and ap- 

 peared also at least to suspend the attacks of gout for a greater 

 length of tune than he had been accustomed to. 



Comparative trials were afterwards made of the effects of the al- 

 kalies and of magnesia upon healthy urine. 



Two drachms of subcarbonate of soda seemed to Mr. Brande to 

 produce its full effect upon the urine in a quarter of an hour after it 

 had been taken, occasioning a precipitation of the phosphates of lime 

 and magnesia, and giving other indications of its presence, by re- 

 storing the blue colour to litmus-paper. 



When supersaturated carbonate of soda was taken, the precipita- 

 tion of the phosphates was less distinct and less rapid, as they re- 

 mained dissolved for some time by excess of carbonic acid in the 

 urine, and then began to appear as a pellicle at the surface by gra- 

 dual escape of the carbonic acid in the form of gas. 



In experiments with potash, the results were the same as when 

 soda was employed. 



Magnesia had also the same effect of occasioning a precipitation 

 of the earthy phosphates ; but on account of its insolubility, a greater 

 length of time was required to produce the effect. 



Lime-water also required as much as five hours to produce a sen- 

 sible precipitation ; and even then it was not nearly so distinct as 

 from the alkalies. 



Since the effects of soda or potash were altered by the presence of 

 carbonic acid, the acid itself was tried alone, by taking twelve ounces 

 of water highly impregnated with carbonic acid ; and as it evidently 

 passed off by the kidneys, and appeared in the urine of a healthy 



