X30 EFFECTS OF MAGNESIA ON URIC ACID. 



The urine voided after tweoty minutes also deposited a 

 tploud of the phosphates; but the transparency of that 

 ^voided two hours after the alkali had been taken was not 

 disturbed. 



Here, therefore, the effect of the alkali upon the urine 

 was at its maxiinuu), probably in less than a quarter of an 

 hour after it had been taken into the stomach, and in less 

 than two hours, the whole of the alkuli had passed off, ;, 



ISxperimeht 2. 0« Soda, with excess ofCdrhbmc AHd, 



Action of the The same quantity of soda, dissolved in eight punce8 of 

 supercarbo- water, very highly impregnated with carbonic ^cid, was 

 ihe urine. taken under the same circumstances as in t||^ former 

 experiment, and the urine was voided at nearly similar in- 

 tervals. 



The. separation of the phosphates was lefs distinct, and 

 less rapid. In two hours after the urine had been voided, 

 there was asraall deposit, composed principally of phosphate of 

 lime ; there was also a distinct ptllicle on the surface, con- 

 sisting of the triple phosphate of ammo^nia and magnesia. 

 This appearance, produced by the escape of the, carbonic 

 acid, which had before retained the ammoniaco-magnesiau 

 phosphate in solution, and which now occasions its deposi- 

 tion on the surface, is by no means uncommon, even in the 

 mine of healthy persons : in the present instance, it appears 

 to prove, that carbonic acid passes off from the stomach by 

 the kidn^es, for after taking the alkajis in water very highly 

 impregnated with it, the pellicle is uniformly produced, and 

 is also much more abundant and distinct, than under any 

 other circumstances. 

 Potash similar 1" similar experiments with potash, the results were in all 

 in its action, cases as similar as could be expected in researches of this 

 nature, 



JExperiment 3. Ow Magnesia, 



Action of mae- Magnesia wns taken, under circumstances similar to tho«e 

 npsiaoothe. of the soda in the former experiment: in the quantity of 

 urine. ba^ i^ drjachm, it produced no sensible effect upon the urine 



4^i"M^S;lb^!:<^i^**l^. 4?yv, i^^3>^;^ HI^^" in the dcse of a 



drachm 



